The Double Cluster re-visited

 

The Double Cluster - NGC 869 and NGC 884. Modded Canon 200d DSLR with Dual Band Filter and 135mm Samyang Lens.

Map Credit: freestarcharts.com

" Both Kurt and Pip have never believed that they have done the Double Cluster justice. When you look at this pair of open star clusters, through binoculars or a widefield eyepiece on  a telescope at low magnification, it is truly magnificent.  The Double Cluster, viewed through the JPO's tripod mounted 11x80mm.binoculars, is a joy to see in its jewel like appearance. If you have a pair of binoculars and it's a clear night in the Northern Hemisphere, why not try and find it between Cassiopeia and Perseus? - Joel Cairo CEO of the Jodrell Plank Observatory.

"The Double Cluster in Perseus, catalogued as NGC 869 and NGC 884, is a striking pair of young, massive open star clusters located in the Perseus arm of the Milky Way Galaxy. Situated at an approximate distance of 7,500 light-years (2.3 kpc) from Earth, the system lies within the Perseus OB1 association, an active star-forming region rich in hot, luminous stars.

Both clusters are estimated to be relatively young, with ages on the order of 12–14 million years, placing them in a comparable evolutionary stage. Their stellar populations are dominated by early-type B-class main-sequence stars and a notable complement of evolved blue and red supergiants, evidence of rapid stellar evolution in high-mass stars. Integrated spectral analyses indicate a near-solar metallicity, consistent with their origin in a typical Galactic spiral-arm environment.

The clusters are physically separated by only a few hundred light-years, suggesting a common origin from the same giant molecular cloud. Their projected angular separation on the sky is approximately 30 arcminutes (roughly the apparent diameter of the full Moon), making them easily distinguishable yet visually connected in telescopic and binocular observations.

Photometric studies of NGC 869 and NGC 884 reveal high stellar densities in their cores, with mass estimates of several thousand solar masses each, placing them among the most massive open clusters in the Milky Way. Their combined luminosity and concentration of bright, blue stars make the Double Cluster an archetypal laboratory for studying the early dynamical evolution of clustered stellar populations.

Owing to their brightness (apparent magnitudes ~+4.3 and +4.4) and their location near the Perseus–Cassiopeia border, the Double Cluster has been recognized since antiquity, though it was first catalogued systematically by Hipparchus around the 2nd century BCE. Today, the system remains a prominent observational target for both professional astrophysical research and amateur astronomy, offering insight into star cluster formation, stellar evolution, and Galactic structure". - Professor G.P.T. Chat visiting astrophysicist at the Jodrell Plank Observatory.

The Heart of the matter

 

IC 1805 and Melotte 15.

"The above images captured at the Jodrell Plank Observatory and also by the PIRATE robotic telescope on Mount Teide, Tenerife (credit telescope .org, Open Observatories, Open University) show the Heart Nebula, IC1805 in increasing detail and reducing field of vision. The top, widefield image was captured with the JPOs modded Canon 200d Camera with a Dual Band filter and a Samyang 135mm lens. The other two were captured by the PIRATE telescope with SHO filters. Pip Stakkert used a number of processing techniques to emphasise the nebulosity". - Kurt Thrust current Director of the JPO.

"The Heart Nebula (IC 1805) is a large emission nebula located in the Perseus Arm of the Milky Way, within the constellation Cassiopeia. At an estimated distance of approximately 6,000–7,500 light-years from Earth, it extends over nearly 200 light-years in diameter, making it one of the more prominent star-forming complexes in the northern sky. Its common name derives from the overall morphology of its extended H II region, which, in wide-field optical images, presents an outline reminiscent of a stylized human heart.

The nebula is primarily excited by the young stellar population of the open cluster Melotte 15, situated near the nebula’s center. This cluster, containing numerous hot O-type and early B-type stars, serves as the dominant ionizing source for the surrounding gas. The intense ultraviolet radiation emitted by these massive stars ionizes the hydrogen in the surrounding molecular cloud, producing the characteristic red glow of Hα emission. Stellar winds and radiation pressure also drive large-scale feedback processes that shape the morphology of the nebula, generating bright ridges, cavities, and dark, pillar-like structures of dense gas.

Of particular note is the brighter nebulosity concentrated near the nebula’s core. This region surrounds Melotte 15 and exhibits a higher surface brightness due to the proximity of the ionizing sources and the resulting density contrast between ionized and neutral gas. Within this core, the interplay between radiation, stellar winds, and turbulence has carved out intricate filaments and luminous fronts, where shock compression has enhanced local gas densities. These conditions are conducive to ongoing star formation: observations at infrared and radio wavelengths reveal embedded protostars and compact H II regions tracing younger generations of stellar objects still enshrouded in dust.

In summary, IC 1805 exemplifies the dual role of massive stars in galactic ecology: while their radiation and winds sculpt and erode the parent molecular cloud, they also trigger subsequent episodes of star formation. The central bright nebulosity of the Heart Nebula, therefore, represents not only a visually striking concentration of emission but also the dynamic hub of stellar feedback and continuing stellar genesis within the complex". -Professor G.P.T Chat and Karl Segin outreach coordinator at the JPO.

The Iris Reflection nebula in the constellation Cepheus

The Iris Nebula in modified SHO format. The PIRATE Robotic Telescope,Mount Teide, Teneriffe.   Data Credit: telescope.org. Open Observatories, Open University. Image Credit: Kurt Thrust.

" Kurt was feeling a little better today and so he and the JPO engineer, Jolene McSquint-Fleming, were busy remaking a diffraction grating for the Seestar S30. They decided to make a grating, which covers the full aperture of the little scope rather than  partially. It will be interesting to see whether this affects the accuracy of the scope's guidance and goto software". - Joel Cairo CEO at the JPO.

The new-recycled magnetic 50 lines/mm
full aperture grating for the Seestar 30

Spectrum produced by the above grating
using the JPO Visitor Centre door security peep hole
as an artificial star.

" If we get a clear night soon, we will try the new grating out and develop a capture process, which enables the removal of stars and hot spots, which otherwise corrupt the  target and calibration spectra". - Kurt Thrust current Director of the JPO.

" The Iris Nebula, cataloged as NGC 7023, is a bright reflection nebula located in the constellation Cepheus, approximately 1,300 light-years from Earth. It is a striking example of a dust cloud illuminated by starlight rather than by its own emission. At its center lies a young, hot star designated HD 200775, whose intense blue-white radiation reflects off surrounding interstellar dust grains. This scattering process preferentially reflects shorter wavelengths, giving the nebula its characteristic bluish hue, much like the mechanism that makes Earth’s sky appear blue.

The nebula spans roughly six light-years across and is embedded within a larger molecular cloud complex. Its structure reveals striking contrasts: bright filaments and wisps where dust strongly reflects starlight, interspersed with dark lanes where dense concentrations of material obscure illumination. Infrared observations have shown that the dust contains complex carbon-rich molecules, including polycyclic aromatic hydrocarbons (PAHs), which are thought to play a role in interstellar chemistry and may represent building blocks of more complex organic compounds.

Unlike emission nebulae, which glow due to ionized gas, the Iris Nebula remains primarily a reflection nebula because the radiation from its central star is not energetic enough to fully ionize the surrounding hydrogen gas. Instead, the nebula’s beauty lies in the interplay of light and shadow, highlighting the distribution of interstellar dust and providing astronomers with insights into the conditions of stellar nurseries". - Professor G.P.T Chat visiting astrophysicist at the Jodrell Plank Observatory.

Enlarged and cropped view of the spectacular Iris reflection Nebula

IC 5070 or the Pelican Nebula in modified SHO format

Ionization fronts and cold gas in the Pelican Nebula. Data Credit: PIRATE robotic telescope SHO filters. Mount Teide, Tenerife. telescope.org Open Observatories, Open University. Image credit: Pip Stakkert at the JPO..

"The Pelican Nebula is a goto target for Northern Hemisphere  summer astro-imagers and sits next to the North America Nebula NGC7000 in the constellation Cygnus. The above narrowband image shows the delicate interplay of light and shadow: the glowing plasma energized by young stars and the cold dark lanes marking where future stars are gestating. The visible filaments trace the ionization fronts—the boundaries between the ultraviolet-irradiated cavities and the shielded interiors of molecular clouds.

In effect, the above image is a portrait of cosmic evolution in progress: the raw interstellar medium being sculpted into stars, planetary systems, and eventually the building blocks of life itself". - Joel Cairo CEO of the Jodrell Plank Observatory.

The North America and Pelican Nebulae in the Constellation Cygnus. Image credit: Kurt Thrust at the JPO

"Our narrow band SHO image, captured with the PIRATE telescope, depicts IC 5070, more commonly known as the Pelican Nebula, a large emission nebula located in the constellation Cygnus, not far from its companion, the North America Nebula (NGC 7000). Both regions are part of an extended complex of ionized hydrogen gas (an H II region) that lies about 1,800 light-years away in the Orion Arm of our Milky Way galaxy.

What we have imaged is essentially a stellar nursery: a vast cloud of hydrogen, dust, and other trace elements undergoing active star formation. The striking forms in IC 5070—its ridges, filaments, and dark channels—arise from the interaction between intense ultraviolet radiation from nearby massive stars and the dense molecular cloud material.

Ionization and Emission

The gas in IC 5070 glows because young, hot O- and B-type stars in the region emit torrents of ultraviolet light.

This radiation strips electrons from surrounding hydrogen atoms, a process known as photoionization. When the electrons recombine with protons, they emit visible light—most notably in the red H-alpha line (656.3 nm). This is why narrowband astrophotography often reveals IC 5070 with a red or magenta dominance.

Dark Dust Lanes

The jagged black regions cutting through the glowing gas are dense molecular clouds of dust and cold gas.

These clouds absorb and scatter visible light, producing the intricate silhouetted structures that make the Pelican Nebula so recognizable. Within these dark regions, protostars are forming, hidden from optical wavelengths but detectable in infrared.

Stellar Feedback

The radiation pressure and stellar winds from massive young stars push against the molecular material, carving cavities, compressing clouds, and triggering further star formation at the boundaries of these regions.

This feedback loop is a defining characteristic of giant H II regions: they are both destroyers and creators—dissipating the nebula even as they seed new generations of stars.

Overall Context

IC 5070, along with NGC 7000, is part of a giant molecular cloud complex spanning several degrees of sky, visible in wide-field astrophotography, (see Kurt's above  image) as a grand tapestry of glowing hydrogen and sculpted dust.

Astronomers often study it as an analog for stellar nurseries in other galaxies, since its proximity gives us a clearer laboratory for understanding massive star formation and interstellar medium dynamics". -Kurt Thrust current Director of the  JPO and Professor G.P.T Chat visiting astrophysicist .

NGC 281 'The Pac-man' Nebula

 

NGC 281- Part of the Pac-man Nebula. Data Credit: PIRATE robotic telescope, SHO filters, Mount Teide, Tenerife. telescope.org. Open Observatories, Open University. Image Credit: Kurt Thrust.

The Constellation Cassiopeia (The big 'W' asterism in the Northern Sky)
A compilation - 3 pane, widefield image.
Captured with the Jodrell Plank Observatory's mini-rig : Canon 600d DSLR
with a 135mm F2 Samyang Lens all on a Star Adventurer EQ mount.
  - Image Credit: Pip Stakkert

" The weather remains poor on the East Coast and sadly Kurt has been laid low by an auto-immune disorder,consequentially, little astronomy has been pursued at the JPO. Kurt did however, enjoy an hour working upon the Pac-man data obtained via the PIRATE robotic scope on Tenerife". - Joel Cairo CEO of the JPO.

NGC 281 in detail

"The NGC 281 nebula, often nicknamed the Pacman Nebula due to its resemblance to the iconic video game character in optical images, is a large, active star-forming region located in the Perseus spiral arm of the Milky Way. Situated in the northern constellation Cassiopeia, this emission nebula lies approximately 9,200 light-years (2.8 kiloparsecs) from Earth. With an angular diameter of nearly 35 arcminutes—comparable to the size of the full Moon—it corresponds to a physical span of over 100 light-years across.

NGC 281 is classified as an H II region, a vast cloud of ionized hydrogen gas energized by the intense ultraviolet radiation from its embedded young stars. At its core lies the open star cluster IC 1590, which hosts a population of hot, massive O- and B-type stars. Among them, the O6 star HD 5005 is particularly dominant, providing much of the ionizing flux that causes the surrounding hydrogen gas to glow in vivid emission lines, especially the characteristic red Hα radiation.

The nebula’s structure is rich and complex, sculpted by stellar winds and radiation. Prominent features include dense Bok globules—cold, dark molecular clumps that appear as silhouettes against the luminous background. These globules are active nurseries where protostars are forming, their growth regulated by the interplay between self-gravity and external radiation pressure. Infrared observations from the Spitzer Space Telescope and more recent surveys with the James Webb Space Telescope (JWST) have revealed numerous young stellar objects (YSOs) and protostellar disks within NGC 281, highlighting its ongoing role as a cradle of stellar birth.

The nebula is also notable for being the site of significant molecular outflows and stellar feedback processes. Winds from the massive stars in IC 1590 compress nearby gas, triggering sequential star formation along the peripheries of the nebula—a process sometimes described as “collect and collapse.” This makes NGC 281 a textbook example for studying how massive stars regulate the evolution of their parent molecular clouds.

From an observational perspective, NGC 281 is accessible with modest amateur telescopes under dark skies, appearing as a faint glowing patch of nebulosity surrounding a small star cluster. Through long-exposure astrophotography, its intricate structure becomes clear, with reddish emission nebulae, dark dust lanes, and striking cavities carved by stellar activity.

In summary:

NGC 281 in Cassiopeia is a luminous emission nebula and star-forming complex, powered by the young cluster IC 1590. Spanning over 100 light-years, it contains dark Bok globules, active protostars, and striking examples of stellar feedback shaping the interstellar medium. Its combination of visual beauty and astrophysical richness has made it both a popular target for amateur astronomers and a significant object of study for professional astrophysics, particularly in the fields of star formation, stellar feedback, and nebular evolution". - Professor G.P.T Chat visiting astrophysicist at he Jodrell Plank Observatory.

Messier 31 revisited

• 
  

 

Messier 31 The Andromeda Galaxy Group. Altair Lightwave 66mm ED refractor and Canon 600d DSLR.
Image Credit Kurt Thrust.

"Our nearest spiral galaxy neighbour the Andromeda Galaxy is riding high in the Northern Hemisphere autumn sky. The weather has been far from kind and the JPO team has been laid low by a rather nasty virus which may be the latest variant of  Covid. Anyway, as the team has been wrapped up warm for a while, Kurt decided to reprocess this data captured in a previous year.

The above image shows the three galaxies M31 (the large central inclined spiral), M32 the elliptical galaxy (appears as a fuzzy spot on the upper edge of the M31 spiral) and M110 a dwarf elliptical galaxy ( just below and to the centre right of M31). 

So let Professor G.P.T. Chat, our visiting astrophysicist, compare and contrast these nearby galaxies (approximately 2.5 million light years distant) with our home Milky Way galaxy". - Joel Caio CEO of the Jodrell Plank Observatory.

Milky Way – Our Home Galaxy

The Milky Way is itself a barred spiral galaxy, somewhat smaller than M31. Its disk extends ~100,000–120,000 light-years, with a mass of about 1 trillion solar masses and a few hundred billion stars. Structurally, it resembles M31: both have stellar halos, bulges, bars, spiral arms, and satellite galaxies. In cosmic terms, the Milky Way is the second major member of the Local Group, and the future collision and merger of the Milky Way and M31 will reshape them into a single giant elliptical galaxy in several billion years.

M31 – The Andromeda Galaxy

Andromeda is the giant of this quartet. With a disk spanning about 220,000 light-years, it is roughly twice the diameter of the Milky Way. Its stellar population approaches one trillion, compared with the Milky Way’s 200–400 billion. In both size and luminosity, M31 slightly outclasses our own Galaxy, and it exerts enough gravitational pull to dominate the Local Group, which also contains the Milky Way and dozens of smaller galaxies.

• Diameter: ~220,000 light-years (about twice the Milky Way’s diameter).
• Mass: ~1.5 trillion solar masses.
• Stars: ~1 trillion.
• Luminosity: ~2.6 × 10¹⁰ solar luminosities.

Notes: A vast spiral galaxy with an extensive stellar halo and a large, bright disk. It dominates the Local Group both in size and gravitational influence.

M32 – Compact Elliptical

Placed against the scale of the Milky Way, M32 looks minuscule. With only ~3 billion stars in a body just 6,500 light-years across, it is smaller than even some of the Milky Way’s largest globular clusters when measured by diameter. Where the Milky Way’s spiral disk is rich in gas and dust and actively forming stars, M32 is stripped bare, almost entirely quiescent. Its compact, blazing core makes it bright for its size, but compared with the Milky Way, it is less than 1% as luminous.

• Diameter: ~6,500 light-years (tiny compared with M31).
• Mass: ~3 × 10⁹ solar masses.
• Stars: ~3 billion.
• Luminosity: ~3 × 10⁸ solar luminosities.

Notes: Dense and bright, especially in its central regions. Its outer stars and gas are thought to have been stripped by M31, leaving only the compact core we see today.

M110 – Dwarf Elliptical

M110 sits somewhere between M32 and the Milky Way in scale. Its 15,000–17,000 light-year span is still tiny compared with the Milky Way’s disk, and its ~10 billion stars are a mere fraction of the Milky Way’s population. Unlike M32, however, M110 retains some irregular features, dust, and evidence of star formation. It is a faint satellite, thousands of times less luminous than the Milky Way, but still large enough to stand as one of the more substantial dwarf galaxies in the Local Group.

• Diameter: ~15,000–17,000 light-years.
• Mass: ~1–2 × 10⁹ solar masses.
• Stars: ~10 billion.
• Luminosity: ~9 × 10⁸ solar luminosities.

Notes: More diffuse than M32, with some evidence of dust lanes and past star formation. Its structure is irregular compared with typical smooth ellipticals, likely reflecting tidal interaction with M31.

Comparative Perspective

M31 and the Milky Way are the two great spirals of the Local Group, differing mainly in scale (M31 being the larger).

M32 is a stripped-down remnant, a tiny elliptical companion of M31, utterly dwarfed by both the Milky Way and Andromeda.

M110 is a diffuse dwarf elliptical, more extended than M32 but still only a faint shadow of the Milky Way’s scale and richness.

Together, these four galaxies illustrate the hierarchy of galactic forms: two massive spirals shaping the Local Group, orbited by much smaller companions that bear the scars of their gravitational relationship with the giants.

The Approaching Collision

• The Milky Way and M31 are moving toward each other at about 110 km/s.

• In roughly 4–5 billion years, their outer halos will begin to overlap, triggering the first close passage.

• The collision will not be like two solid bodies smashing together; instead, stars will mostly pass by one another because of the vast spaces between them. But gas, dust, and dark matter halos will interact strongly, producing shocks, bursts of star formation, and tidal distortions.

The Merger

• After a series of close encounters, the Milky Way and M31 will merge into a single giant elliptical galaxy — sometimes nicknamed “Milkomeda” or “Milkdromeda.”

• This process will take several billion years to settle into a stable form. The final product will likely resemble today’s giant elliptical galaxies, with a vast stellar halo and little organized spiral structure.

---

The Fate of M32

• M32, already stripped and compact, is tightly bound to M31.

• During the merger, it will almost certainly be swallowed whole by the combined Milky Way–Andromeda system.

• Its compact nature means it will survive tidal forces fairly well, likely ending as a dense nucleus or central star cluster within the merged galaxy.

---

The Fate of M110

• M110, being larger and more diffuse, will fare differently.

• It may be torn apart by tidal forces during the merger, with its stars spread out into long stellar streams and absorbed into the halo of the new galaxy.

• Some fraction of its stars may survive as a remnant dwarf core, but it will be much more disrupted than M32.

The Long-Term Result

• The Local Group will transform from a system dominated by two spirals into a single elliptical super-galaxy, containing perhaps 2 trillion stars.

• The smaller companions, including M32, M110, and the Milky Way’s own satellites (like the Magellanic Clouds), will either be absorbed into the giant remnant or left orbiting as faint shells and streams.

• From a cosmic distance, the Local Group will eventually resemble a single luminous elliptical galaxy, drifting in relative isolation as the universe continues to expand.

 In short: M31 and the Milky Way will merge into one great elliptical galaxy; M32 will likely become part of its core, while M110 will be torn apart and assimilated into its halo.

Messier 71, the easy to miss Globular Star Cluster.

 

The Globular Star Cluster Messier 71. Data Credit: PIRATE robotic telescope, BVR filters. Mount Teide, Tenerife. telescope.org. Open Observatories, Open University. Image Credit: Kurt Thrust at the JPO.

" Messier 71, sits in the  small constellation Sagitta the arrow. This area of the sky is associated with the plane of the Milky Way's disc and is literally awash with stars when viewed with binoculars or a widefield telescope. Messier 71 being a small globular cluster, is therefore easy to miss within this plethora of stars. As I processed the data and watched the above image materialise, I  was amazed at how many stars I could see!" - Kurt Thrust current Director of the Jodrell Plank Observatory.

A Comparative Report on the Globular Cluster Messier 71

Messier 71 (M71), located in the small constellation Sagitta, is one of the more unusual globular clusters in the Messier catalogue. At a distance of roughly 13,000 light-years, it appears as a loose, irregular grouping of stars through modest telescopes, and for much of the 19th and 20th centuries it was debated whether M71 was in fact a globular or a rich open cluster. Advances in stellar photometry and spectroscopy have since clarified its nature: M71 is a genuine globular cluster, though a relatively low-mass, metal-rich, and loosely concentrated one. Comparison with the more archetypal clusters Messier 13 (M13), Messier 3 (M3), and Messier 4 (M4) underscores the peculiarities of M71.

Messier 13, the “Great Hercules Cluster,” is perhaps the best-known northern globular cluster. It contains several hundred thousand stars in a compact halo over 140 light-years across, with a dense, bright core that exemplifies the globular class. By contrast, M71 contains perhaps only 20,000–50,000 stars spread across a mere 27 light-years. Its lower concentration and modest size explain why early observers mistook it for an open cluster. Whereas M13 presents a dazzling display of densely packed stars and exhibits a well-defined horizontal branch, M71 has only a stubby red giant branch and no extended blue horizontal branch, making its stellar population appear more subdued.

Messier 3 provides another instructive comparison. Situated in Canes Venatici, M3 is among the richest and most extensively studied globular clusters, hosting over half a million stars and more than 200 known variables, including numerous RR Lyrae stars. Its variable population and prominent horizontal branch have made it a cornerstone for calibrating stellar evolution models. M71, on the other hand, lacks a significant RR Lyrae population and is chemically distinct. Its relatively high metallicity ([Fe/H] ≈ –0.8) is atypical for globular clusters, especially when contrasted with the metal-poor stars of M3. This implies that M71 formed later in the Galactic halo’s history, from interstellar gas already enriched with heavier elements, and therefore represents a younger evolutionary epoch within the globular cluster system.

Messier 4, in Scorpius, provides a comparison from the opposite end of the structural spectrum. Though M4 is one of the closest globular clusters to Earth (about 7,200 light-years), and not especially rich in stars compared to giants like M3 or M13, it nevertheless displays a clear globular morphology with a strong central concentration. M4 is notable for its rich population of evolved stars, a well-populated horizontal branch, and chemical peculiarities linked to multiple stellar generations. In terms of mass and richness, M4 is closer to M71 than are M13 or M3, yet it retains the compact, globular appearance that M71 lacks. The difference lies primarily in concentration: M4 is compact and easily recognisable as a globular cluster, while M71 is diffuse, giving it a hybrid appearance that complicated its classification.

In conclusion, M71 highlights the diversity within the globular cluster family. It lacks the immense stellar density and archetypal morphology of Messier 13, the vast population and chemical simplicity of Messier 3, and even the structural clarity of Messier 4. Instead, it is a relatively loose, metal-rich, and moderately populated globular cluster, whose transitional characteristics blur the distinction between open and globular clusters. Its study provides valuable insight into the chemical enrichment of the Galaxy and the lower-mass limits of globular cluster formation.

Professor G.P.T. Chat visiting astrophysicist at the Jodrell Plank Observatory.

The Wizard of Cepheus NGC 7380

 

NGC 7380 The Wizard Nebula in the constellation Cepheus.
Data Credit: PIRATE robotic telescope, SHO filters. Mount Teide.  Tenerife
telescope.org. Open Observatories, Open University.
Image Credit Pip Stakkert at the JPO.

Annotated version of the image. Credit: astrometry.net.

" Pip has taken his own view on the final colours used in this narrow band image. The original data was captured with SHO filters which were mapped to RGB. Hydrogen alpha emission is particularly strong in NGC7380 and therefore 'green' predominates. Pip has adjusted the colour intensity to bring out the 'red' (Sulphur ll) and  blue (Oxygen lll) datas".

I should like to thank Alan Waffles and Waffles Construction Ltd for coming at short notice, to batten down one of the rooves at the JPO, prior to the arrival of high winds and heavy rain. In the event, the storm  wasn't as bad as was predicted and no damage was sustained".- Joel Cairo CEO of the Jodrell Plank Observatory.

" I asked Karl Segin, the JPO's outreach officer and Professor G.P.T Chat our visiting astrophysicist, to put together a brief description of the Wizard Nebula. I hope, like me, you find this enigmatic object interesting" - Kurt Thrust current Director of the Jodrell Plank Observatory.

 NGC 7380: The Wizard Nebula

NGC 7380, commonly referred to as the Wizard Nebula, is a young open star cluster surrounded by an extensive emission nebula. It is located in the constellation Cepheus, at an estimated distance of about 7,200 light-years from Earth. The nebula spans approximately 100 light-years across, making it a prominent star-forming region visible in long-exposure astrophotography. Its popular name arises from the resemblance of the illuminated gas clouds to a robed, wizard-like figure when viewed in visible light images.

The central feature of NGC 7380 is the open star cluster, cataloged by Caroline Herschel in 1787 and later added to William Herschel’s general catalog. This cluster is only a few million years old and contains a rich population of hot, massive O-type and B-type stars, whose strong ultraviolet radiation energizes the surrounding hydrogen gas. The nebula itself is classified as an H II region, a vast cloud of ionized hydrogen where new stars are actively forming.

The process that created the Wizard Nebula follows the standard sequence of stellar nursery evolution. A large molecular cloud of hydrogen and trace elements began to collapse under the influence of its own gravity. Local density enhancements triggered pockets of rapid star formation. As the most massive stars ignited nuclear fusion in their cores, they released intense radiation and powerful stellar winds. This feedback carved cavities in the surrounding cloud, compressing some regions while dispersing others. The result is the sculpted appearance of bright ridges, dark dust lanes, and filamentary structures that give the nebula its dramatic shape.

Embedded within the nebula are protostars and young stellar objects still accreting matter from their natal environment. Observations in infrared wavelengths, which can penetrate the obscuring dust, have revealed numerous stars still in their formative stages. Some of these may eventually join the cluster, while others will disperse as the nebula continues to evolve.

The fate of NGC 7380 will be shaped by its most massive stars. Within a few million years, these stars will end their lives as supernovae, enriching the interstellar medium with heavy elements and possibly triggering further rounds of star formation in the region. Over time, the gas and dust of the Wizard Nebula will disperse into the wider galaxy, leaving behind the open cluster, which itself will gradually lose cohesion due to gravitational interactions.

Today, NGC 7380 is an object of great interest to both professional astronomers and astrophotographers. It provides a natural laboratory for studying the physics of star formation, stellar feedback, and nebular evolution. Its striking appearance, combined with its role as an active stellar nursery, makes the Wizard Nebula one of the most evocative examples of the dynamic processes shaping our Milky Way galaxy.

The Sun today - 07_09_2025

 

The Solar photosphere captured in white light
using - the JPO's 66mm.Altair Lightwave ED refractor, A Baader safety film objective mounted filter, a QHY5lll462c video camera with stacked UV-IR filter and green light filter. All on a Star Adventurer EQ mount.

"The JPO team was all out today getting kit organised for imaging the eclipsed Moon tonight as it rises above the North Sea horizon from Pakefield Cliffs. Sadly, as the day has gone by the clouds have rolled in and the chances of seeing anything of the eclipse tonight appears to be remote. 

Anyway the clouds did stay away long enough  for Kurt to capture some photons of our nearest and dearest star, 'The Sun'.

We certainly captured a lot of sunspots in the two x 1 minute video clips we took on the day.

We tried, for the first time, using a green filter stacked with our usual UV-IR filter as we had been advised that this can help to resolve more sunspot detail. We think this was the case but a red filter similarly stacked is better for 'show-casing' faculae.

Just take a moment to look at the above image and take in that the Sun's diameter (at the level of the photosphere) is 1.39 million km. By comparison the Earth's diameter measured at the Equator is just 12,760 km. The Sunspots appear tiny in the image but in reality could swallow the Earth whole"

The Solar Photosphere and current Solar Activity

• The photosphere is the Sun’s visible surface—the layer that emits most of the light we see—spanning just 100–400 km thick, with an effective temperature near 5,772 K 
• In this layer, convection emerges as a granular texture - if you look carefully at the above image you can see the granulation:
• Granules—tiny, boiling convection cells—are around 1,500 km in diameter, lasting up to 15–20 minutes 
• .Larger supergranules span up to 30,000 km and last about 24 hours, driving magnetic field flows 
• The photosphere’s granulation drives the movement and emergence of magnetic fields that define sunspots and active regions.

Sunspots & Magnetic Suppression

• Sunspots are cooler (~3,500 K vs. ~6,000 K of surrounding photosphere) due to intense magnetic fields that inhibit convection, appearing dark 
• These strong magnetic structures form the roots of magnetic loops that extend into the chromosphere and corona, often associated with solar flares and energetic events 

Current Solar Activity (Summer 2025)

• As of now, the Sun is in Solar Cycle 25, which reached its maximum sunspot activity around late 2024, with numbers around 160 for smoothed monthly peaks 
• .Recent measurement show sunspot number around 108, with new active regions emerging and moderately elevated 10.7 cm radio flux (~146 sfu) 
• However, activity is gradually declining from the peak, with solar flux levels about half of the cycle’s peak by mid-2025 
• .Daily sunspot counts have varied—ranging between ~130–154 in early August 2025"

-Karl Segin outreach coordinator at the Jodrell Plank Observatory.

The stars of the Summer Triangle asterism

The stars of the Summer Triangle: Deneb, Vega and Altair.
All images and spectroscopy captured and processed
by Kurt Thrust at the Jodrell Plank Observatory

" Kurt asked our visiting astrophysicist, Professor G.P.T Chat, to provide some features to look for in the above spectral line profiles and the stellar physics behind them". - Joel Cairo CEO of the JPO.

" An asterism is a recognizable pattern of bright stars in the sky. It may be formed from some of the brighter stars in a constellation, for example the Plough, which includes some of the stars of Ursa Major the Great Bear or a recognizable pattern of bright stars from several constellations, as is demonstrated by the Summer Triangle,which is comprised from the three alpha stars Deneb (Cygnus), Vega (Lyra) and Altair (Aquila). - Karl Segin outreach officer at the JPO.

Big picture

All three are A-type, blue-white stars, so they share strong hydrogen Balmer absorption and relatively sparse molecular features.

They differ mainly in luminosity class and rotation, which change how those same lines look: Deneb is a supergiant (Ia), Vega a near-textbook A0 main-sequence star (V), and Altair a late-A dwarf (A7 V) and extreme rapid rotator.

Where they sit on the HR diagram

Star Spectral type Luminosity class Evolutionary state

Deneb (α Cyg) ~A2 Ia (luminous supergiant) Massive star evolving off the main sequence; on its way through/around the supergiant phases

Vega (α Lyr) A0 V (dwarf) Middle-age main-sequence star, H-burning

Altair (α Aql) A7 V (dwarf) Main-sequence star; very fast rotator (oblate, gravity-darkened)

What your low-res spectra should show

Hydrogen Balmer lines (Hα, Hβ, Hγ, …)

Strongest near A0 → Vega should show the deepest Balmer absorption.

Altair (A7): Balmer lines still strong, but shallower than Vega; metal lines begin to stand out more.

Deneb (A2 Ia): Balmer lines are strong but shaped by low surface gravity—you may notice broad wings with comparatively narrow cores, and in some epochs wind effects (subtle emission infilling or weak P-Cygni signatures in Hα) even at low resolution.

Metal lines (Ca II K at 393.3 nm, Mg II ~448.1 nm, Fe II blends)

Altair: As the latest-type of the three, it should show relatively stronger metal lines than Vega.

Vega: Cleaner A0 spectrum—metals present but less prominent than in Altair; it’s also a mild metallicity-peculiar standard, so don’t be surprised if some metal features look a tad weaker than “textbook.”

Deneb: Despite being only slightly later than Vega by type, the supergiant’s low gravity enhances certain ionized metal lines (e.g., Fe II, Si II) and can make them more conspicuous than in Vega.

Line widths & shapes

Altair rotates extremely fast (period ~9–10 h), so its absorption lines are noticeably broadened even at low resolution.

Vega is also a rapid rotator but seen nearly pole-on, so its projected line broadening is modest—lines look crisper than Altair’s.

Deneb has low gravity and stellar winds; expect less rotational broadening, but broader Balmer wings and occasional wind-affected Hα profiles.

Continuum slope & reddening

Deneb is thousands of light-years away; interstellar reddening can tilt its continuum redward compared with nearby Vega (25 ly) and Altair (17 ly). If the data reduction didn’t fully de-redden Deneb, its spectrum may look slightly warmer/redder than its type alone would suggest.

Physical contrasts that drive those spectral looks

Temperature (rough): Vega ~9,600 K (hottest), Deneb ~8,500 K, Altair ~7,500 K on average (equator cooler than poles from gravity darkening).

⇒ Explains: Vega’s strongest Balmer, Altair’s stronger metal lines, Deneb’s A-type look despite being a supergiant.

Surface gravity (log g): Deneb is very low (supergiant), Vega/Altair are higher (dwarfs).

⇒ Low gravity in Deneb = narrower cores, extended Balmer wings, and stronger ionized metal lines than you’d expect for a dwarf at similar temperature.

Rotation: Altair’s v sin i is huge → rotational broadening across many lines; Vega rotates fast intrinsically but looks sharper because we see it nearly pole-on; Deneb’s spectrum is dominated more by wind + low gravity than rotation.

Luminosity & radius: Deneb is enormously luminous (hundreds of thousands L☉) with a radius of hundreds of R☉; Vega (~40 L☉, ~2.4 R☉) and Altair (~10–12 L☉, ~1.7–2 R☉) are compact by comparison.

⇒ Deneb’s wind features and low-g line morphologies vs. the neat, pressure-broadened dwarf lines in Vega/Altair.

Environments: Vega hosts a well-known debris disk (you won’t see the disk in the spectrum, but it’s part of its story). Altair doesn’t show a comparable far-IR excess. Deneb has a stellar wind and slight α Cygni-type variability, which can subtly change Hα over time.

Quick “at a glance” checklist for the spectral profiles

Deepest Balmer lines? → Vega (A0 V).

Broadened lines overall? → Altair (rapid rotation).

Balmer wings + possible Hα infill, stronger Fe II/Si II for an A-star? → Deneb (A-supergiant, wind + low gravity).

More prominent Ca II K & other metal lines vs Vega? → Altair (later A-type).

Continuum looks a bit redder than expected? → Likely Deneb (distance + interstellar reddening

Epsilon Lyrae 1 and 2

 

Epsilon Lyrae the multiple star system.
Data Credit: PIRATE robotic telescope (Clear and BVR filters).
telescope.org, Open Observatories, Open University.
Image Credit: Kurt Thrust.

"In a dull moment at the Observatory, the JPO Team fell into conversation about the famous double double star, Epsilon 1 and 2, in the constellation Lyra.No one was sure as to whether they had seen the gravitationally bound stellar system through a telescope eyepiece which resolved the target into four stars. Kurt thought that he had once achieved this with the JPO's 127mm refractor at high magnification but if he had it was so long ago that he could not be sure. We looked through the JPO's extensive archive of images but could find none relating to Epsilon Lyrae. As an afterthought, Kurt programmed the PIRATE telescope to capture an image. Clearly the large aperture PIRATE robotic telescope on Mount Teide had sufficient aperture but insufficient magnification to split the star system into four separate stars". - Joel Cairo CEO of the Jodrell Plank Observatory.

" Joel asked me to provide the following overview for the Epsilon Lyrae star system:

Epsilon Lyrae: The Double Double

Situated near the bright star Vega in the constellation Lyra, Epsilon Lyrae is among the best-known multiple star systems in the northern sky. To the unaided eye, it appears as a single faint star of about fourth magnitude, but through even a modest pair of binoculars it is revealed as a close double — two nearly equal stars separated by about 208 arcseconds. These two components are traditionally labeled ε¹ Lyrae (the western pair) and ε² Lyrae (the eastern pair).

What makes Epsilon Lyrae remarkable is that each of these stars is itself a tight binary. Thus, the system has earned the nickname the Double Double. Through a telescope of about 100 mm (4 inches) aperture under steady seeing, each component can be resolved into two stars. The separations are small:

ε¹ Lyrae (STF 2382) splits into a pair of magnitude 5.1 and 6.1 stars, separated by only 2.6 arcseconds.

ε² Lyrae (STF 2383) splits into a slightly wider pair of magnitude 5.4 and 5.5 stars, with a separation of 2.3 arcseconds.

Both pairs orbit each other over timescales of centuries, and the wider ε¹–ε² pairing is gravitationally bound, though the orbital period is measured in tens of thousands of years. The geometry of the system gives observers a striking contrast: ε¹’s stars are aligned roughly north-south, while ε²’s pair is oriented nearly east-west. This nearly orthogonal arrangement makes the system especially pleasing to amateur astronomers who succeed in splitting all four stars.

From a physical standpoint, the Epsilon Lyrae stars are main-sequence A-type stars, somewhat hotter and more massive than the Sun, shining white due to their surface temperatures of around 8,000–9,000 K. They lie at a distance of about 162 light-years (49.6 parsecs).

In observational astronomy, Epsilon Lyrae is often used as a test of both atmospheric seeing and optical resolution. Smaller telescopes may split the wide pair (ε¹ vs ε²), but only instruments of sufficient aperture and magnification under steady skies will reveal the close binaries that make the system a true Double Double". - Professor G.P.T Chat visiting astrophysicist at the Jodrell Plank Observatory. 

The Realm of Galaxies

 

The Realm of Galaxies in the Constellation Virgo. Seestar S30 402x10 sec subs in Alt-Az mode. Data captured from Suffolk in spring 2025. Image Credit: Pip Stakkert.

"The above image depicts a deep-sky view of the Realm of Galaxies in the constellation Virgo, a region that is one of the richest nearby concentrations of galaxies observable from Earth. This area is dominated by the Virgo Cluster, the central component of the larger Virgo Supercluster, of which the Local Group (containing the Milky Way and Andromeda) is a small part. The line of galaxies (running vertically centre right) is known as Markarian's Chain.

The Realm of Galaxies

The term "Realm of Galaxies," introduced by Edwin Hubble in the mid-20th century, refers specifically to the Virgo Cluster of galaxies, situated at a distance of about 54–65 million light-years from Earth.

This cluster contains more than 1,300 confirmed galaxies, with estimates of up to 2,000 members. The population includes giant ellipticals, spirals, irregular galaxies, and numerous dwarf ellipticals.

The Virgo Cluster is gravitationally bound and exerts significant dynamical influence on the motions of galaxies in the Local Supercluster.

The image above shows a wide-field survey view of the Virgo Cluster core region. Several important galaxies can be identified :

Elliptical Giants (Center-right, glowing regions)

Bright, extended objects with smooth light profiles correspond to giant elliptical galaxies such as M84 (NGC 4374) and M86 (NGC 4406).

These galaxies dominate the dense cluster core and are rich in globular clusters and hot X-ray gas.

M87 (Virgo A)

This supergiant elliptical galaxy is among the most massive galaxies in the local universe, containing a supermassive black hole of ~6.5 billion solar masses, famously imaged by the Event Horizon Telescope.

Spiral Galaxies

Edge-on streak-like structures visible across the field correspond to spirals, such as NGC 4388 or NGC 4438, which are undergoing gravitational interactions and ram-pressure stripping due to the intracluster medium.

Intracluster Medium & Dwarfs

The faint reddish diffuse glow represents background stars, dust, and possibly intracluster light produced by stripped stars from past galactic interactions.

The field is peppered with dwarf ellipticals and irregular galaxies, which are abundant in the cluster but often difficult to discern individually without deep surveys.

Scientific Importance

The Virgo Cluster serves as a laboratory for galaxy evolution, as interactions and environmental effects (tidal stripping, ram-pressure stripping, and mergers) can be directly studied.

It provides an anchor point for the extragalactic distance scale, with Cepheids and surface brightness fluctuations used to refine measurements of the Hubble constant.

The cluster's gravitational well shapes the Local Velocity Field, influencing the peculiar motions of nearby galaxies, including the Milky Way".- Professor G.P.T Chat visiting astrophycist at the JPO.

Comet K1 (ATLAS) in the constellation Hercules

 

Comet K1 (ATLAS) powering through Hercules.
Seestar S30 image credit: Kurt Thrust

" This comet is not to be confused with interstellar Comet 31 (ATLAS) which is currently in the constellation Libra. Comet K1 is on a parabolic orbit around the Sun and is a visitor from the Oort Cloud. Comet 31 is on a hyperbolic course from well beyond the Oort Cloud and the Solar System". - Joel Cairo CEO of the JPO.

"Comet C/2025 K1 (ATLAS) is a newcomer from the farthest reaches of our solar system, making its very first visit close to the Sun. Discovered in late May 2025, it's shooting in on a highly eccentric, tilted orbit, taking it closer to the Sun than Mercury ever gets.

In August, it's still faint—only visible through strong amateur telescopes. But by early October, as it dives toward the Sun, it might brighten enough to be seen with binoculars or small telescopes.

The big question: will it survive the solar heat? With a small nucleus and unusual orbit, it's quite possible the comet may break apart as it zips past the Sun. If it holds together, late November might offer another viewing opportunity when it's closer to Earth but dimmer.

We can think about this comet's “age” in two ways:

Formation Age

• Like most comets, K1 (ATLAS) formed about 4.5 billion years ago, during the birth of the solar system.

• It’s made of the same primordial ices and dust that went into forming planets, but it was ejected outward by the giant planets’ gravity early in solar system history.

Dynamical Age (Time in the Oort Cloud)

• It’s considered a dynamically new comet, meaning this is likely its first ever passage into the inner solar system.

• That implies it has spent essentially its entire existence (billions of years) stored in the cold, dark Oort Cloud, preserved in nearly pristine condition.

Sad to think that its first journey to the centre of the Solar System may be its last". -  Professor G.P.T Chat visiting astrophysicist  at the JPO.

34 Cygni an unusual star in Cygnus the Swan

 

34 Cygni aka P Cygni in the constellation Cygnus.
PIRATE robotic telescope with BVR filters, Mount Teide, Teneriffe.
Data credit: telescope.org. Open Observatories, Open University.
Image Credit: Pip Stakkert at the JPO.

Annotated Image credit Astrometry .net.

Why is 34 Cygni unusual:

• 34 Cygni is unusual because it is not a single star, but a symbiotic binary system. That means it’s made of two very different stars orbiting each other:
• A cool red giant, which has a very extended, bloated atmosphere.
• A hot companion (likely a white dwarf), which shines with intense ultraviolet light.
• The giant loses gas, and the hot companion excites and ionizes this gas, producing a glowing nebula-like envelope around the system. Because of this, 34 Cygni shows features of both a cool star and a hot star mixed together in its spectrum.

34 Cygni is classified as a symbiotic star of type S. Its peculiarities arise from the interaction between its components:

Binary Composition

• M-type red giant donor: contributes strong molecular bands (TiO, VO, CN), characteristic of a cool photosphere (T_eff ≈ 3200–3600 K).
• Hot compact companion (white dwarf): provides ionizing radiation (T_eff > 50,000 K) that excites emission lines in the red giant’s wind.

Spectral Profile Features

• Cool star absorption spectrum:
• Broad molecular bands (TiO, VO) dominating the optical.
• Strong continuum slope toward the red.
• Superposed emission spectrum:
• Hydrogen Balmer lines (Hα, Hβ, Hγ, etc.) in strong emission.
• Helium lines (He I, sometimes He II) from higher excitation regions.
• Forbidden lines ([O III] 5007 Å, [Ne III], [N II]) from the ionized nebular gas around the binary.
• Occasionally, Raman-scattered O VI lines around 6825 Å and 7082 Å, which are diagnostic of symbiotic systems.

Why Kurt Thrust and his team want to capture 34 Cygni's spectrum as a 'try out' for the new diffraction grating affixed to the Seestar S30.

• Most stars show either an absorption spectrum (normal stars) or an emission-line spectrum (nebulae, hot stars with winds).
• 34 Cygni shows a hybrid spectrum, with both molecular absorption and nebular emission simultaneously.
• Its spectral variability over time reflects mass transfer episodes, changes in the red giant wind, and accretion activity on the white dwarf.
• The JPO team has not captured spectral data for this star before and Kurt loves a challenge.

 Summary:

• 34 Cygni is unusual because it is a symbiotic binary, displaying both red giant absorption bands and nebular emission lines. In a low-resolution spectrum you’d see molecular TiO absorption from the cool star, plus bright emission lines of hydrogen, helium, and forbidden ions, giving it a “mixed identity” unlike normal stars.
• Prof  G.P.T Chat has theoretically constructed the following spectral profile simulation for a binary star system like 34  Cygni. We shall compare the theoretical profile with the actual profile captured at the JPO."

- Joel Cairo CEO of the Jodrell Plank Observatory.

Stop press: 

• The clouds cleared and the Seestar S30 plus diffraction grating captured zero and first order spectra for 34 Cygni together with a calibration set for Vega. Yet to see if we can create meaningful profiles from the data using BASS software. This will be the subject of a future post. Jolene, has used the feedback from the performance of the prototype, to make some minor modifications to the design of the grating holder, in order to reduce the overall length of spectra on the Seestar S30's sensor.

"Astronomy is temporarily on hold at the JPO as its sponsor, Anita Roberts will be 75 years old this week and she is the JPO Team's favourite star. There will be much jollity and partying in the JPO Visitor Centre this week!! Give Comet the Cat another 'goldfish'! " - Kurt Thrust current Director of the Jodrell Plank Observatory.