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.

Aurora October 2024 - visible to the naked eye over the Jodrell Plank Observatory.

 

Aurora Borealis -visible from Latitude 52 degrees North
-Taken with a handheld Canon 600d DSLR in the early hours, October 2024.
Image Credit: Kurt Thrust.

"What causes the aurora ?

• The aurora borealis (also called the northern lights) happens when tiny charged particles from the Sun — mostly electrons and protons — reach Earth.

• The solar wind: The Sun constantly releases a stream of these charged particles, called the solar wind.

• Earth’s magnetic field: Our planet has a magnetic field, shaped a bit like a bar magnet, with field lines curving out from the north and south poles. This field usually shields us from most of the solar wind.

• Particles guided to the poles: Some solar wind particles get caught in Earth’s magnetic field and are funneled down toward the poles along those field lines.

• Collision with the atmosphere: When these particles collide with gases high up in the atmosphere (mostly oxygen and nitrogen), the gases become “excited.” As they calm down, they release light — that glowing curtain of green, red, or purple we call the aurora.

• So, the aurora is basically the Earth’s atmosphere lighting up because of a storm of solar particles guided in by the magnetic field.

Why is it usually only near the Earth's North and South poles?

• The Earth’s magnetic field directs incoming solar particles toward the polar regions. This creates a kind of “auroral oval” — a ring-shaped zone around the magnetic poles where auroras usually appear.

• Most of the time, this oval sits well within the Arctic Circle (for the north), meaning the northern lights are a common sight in places like Norway, Sweden, Finland, Canada, and Alaska.

• Why only rarely in the UK at Latitude 52°N?

• The UK is much farther south than the usual auroral oval. For people at that latitude to see the aurora, something special must happen:

• Solar storms: Occasionally, the Sun produces a particularly powerful burst of particles, such as from a coronal mass ejection (CME).

• Solar storms can cause an expansion of the auroral oval: When such a strong storm reaches Earth, it pushes the auroral oval outward, expanding it farther from the poles. During big storms, it can stretch far enough south that the lights become visible from northern England or even further south.

• That’s why the aurora in the UK is rare — it takes unusually strong solar activity to push the lights down that far.

The Solar Disc captured in white light from the JPO in Summer 2024.
The Sun's Photosphere shows lots of dynamic activity with, sunspots and faculae on display. Image Credit: Kurt Thrust.

Imagine the Sun as a great ball of energy, constantly sending out streams of tiny charged particles, like sparks from a bonfire. This stream is called the solar wind. Most of the time, Earth’s magnetic field shields us from the particles, deflecting them away. But near the north and south poles, the field acts like a funnel, guiding some of them down into our atmosphere.

When the particles finally reach the thin air high above Earth, they crash into atoms of oxygen and nitrogen. Those atoms get “excited” for a moment, then calm down by releasing energy as light. That light is what we see as the aurora.

The color depends on which gas is struck and at what height. Oxygen high up glows a soft red, lower down it shines bright green — the most common color. Nitrogen adds streaks of purple or pink. Together, they paint the sky like nature’s neon sign.

Energised atmospheric Oxygen and Nitrogen atoms releasing photons at differing wavelengths creating the red, green, purple and pink auroral colours.
Credit: Pip Stakkert at the JPO.

The shape of the aurora — those tall shimmering curtains — comes from Earth’s magnetic field lines. Charged particles flow along those invisible lines, lighting them up like glowing threads. And because the solar wind is gusty and Earth’s magnetic field quivers under the strain, the aurora doesn’t sit still. It flickers, ripples, and waves, as though the sky itself were alive and dancing.

The Aurora Borealis dancing over the JPO
- Credit: Anita and George Roberts

Usually, this show stays tucked safely within the Arctic Circle, because that’s where the magnetic funnel is strongest. But when the Sun sends a particularly powerful blast — a storm of particles — the glowing oval around the pole expands. On rare nights, it stretches far enough south that people in the United Kingdom, even at latitude 52° north, can look up and catch the northern lights painting their skies". Professor G.P.T Chat visiting astrophysicist at the Jodrell Plank Observatory.

Low resolution Stellar Spectroscopy and the Seestar S30

 

Two 3d printed grating holders with iron dust doped epoxy resin.
(The Seestar S30 uses magnetism to affix external filters).
- Credit: Jolene McSquint-Fleming.

The SolidCad generated grating holder model for 3d printing. 
- Credit: Jolene McSquint-Fleming

The 50 lines/mm transmission grating
(sourced 'off the shelf' from China via the Internet for less than £10)
sitting on a laptop next to a 3d printed grating holder.
- Credit: Jolene McSquint-Fleming 

Ken Harrison's Excel Spreadsheet (SimSpec V4_4a)
- Credit K.M. Harrison

The completed Seestar S30 compatible objective lens mounted
50 lines/mm. transmission grating glued to the
3d printed iron dust doped holder
awaiting attachment (upper face down) and
magnetically to the Seestar smart telescope. 
Credit: Jolene McSquint-Fleming
(distantly related by marriage to Bob Fleming).

"Our ever resourceful engineer at the JPO, Jolene Mc Squint-Fleming, has been beavering away in the JPO's 'Clean-room' to make a Mark 4 prototype objective lens mounted slitless low resolution transmission grating spectrometer for the Observatory's Seestar S30 smart telescope. Previous prototypes have been partially successful in that they delivered stellar spectra using an 80 lines/mm grating. Unfortunately the star (zero order) and its first order spectrum could not be contained within the longest side of the Seestar's deepsky imaging sensor. This is not essential but it does aid spectrum calibration by having a zero point together with the first order spectrum, blue through red, in one field of vision. The JPO team recommend, to anyone wishing to develop an interest in stellar spectroscopy, Ken Harrison's excellent book 'Astronomical Spectroscopy for Amateurs' (The Patrick Moore Practical Astronomy Series) Paperback – 9 Feb. 2011

by Ken M. Harrison (Author). 

The next to last of the above images shows Mr Harrison's Excel spreadsheet which given the application inputs of a telescope, camera and diffraction grating calculates a number of useful spectral related features and confirms whether or not the zero to red first order spectrum will fit on the camera sensor. 

The night sky may be appreciated in many ways. For some, just looking up at the  beauty of the stars and planets is enough but for others finding out how the Universe works is a strong driving force. 

In the distant past, astronomers and scientists believed that all humanity could ever know about stars were their position in the sky, their colour and their apparent and relative brightness. It is no exaggeration to say that the science and practice of spectroscopy changed this severely limited expectation and has provided not only comprehensive information about galaxies, stars, and other cosmic matter but also about the space between them. It might be said that 'Spectroscopy' provided both the foundation and prime tool for  the development of the science of  'Astrophysics'.

The early days of 'Spectroscopy' 

The “fathers” of astronomical spectroscopy are generally considered to be:

Joseph von Fraunhofer (1787–1826)

He built some of the best early spectroscopes and discovered the dark absorption lines in the solar spectrum (now called Fraunhofer lines) around 1814.

His work laid the foundation for using spectra to study the Sun and stars.

Gustav Kirchhoff (1824–1887) & Robert Bunsen (1811–1899)

In the 1850s–1860s, they showed that each chemical element produces a unique spectral “fingerprint” of emission and absorption lines.

They were the first to identify chemical elements in the Sun and stars using spectroscopy, proving that the stars are made of the same elements found on Earth.

Together, Fraunhofer, Kirchhoff, and Bunsen are usually credited as the founders of astronomical spectroscopy.

So what are the Jodrell Plank Observatory goals for the use of spectroscopy and what tools can we use to achieve them?

Kurt and his team have already designed and made a 500 lines/mm spectrometer and have captured and processed stellar spectra for a number of stars using the JPO 127mm Meade refractor. The results have been quite encouraging but capturing and processing data using this telescope-spectrometer  is very resource and time hungry. As a consequence the number of stars for which spectra have been obtained from the JPO is quite small. 

Comparative Spectral Profiles for the Stars Altair, Alshain and Tarazed captured with the 500 lines/mm spectrometer attached to the JPO's 127mm Meade refractor. (three we did earlier)

500 lines/mm. Spectrometer
utilising the QHY5-11 mono camera.
Credit: J.McS-F and Kurt Thrust.

The team would like to do more spectroscopy combined with standard imaging using kit that can be quickly and easily deployed. If the Seestar S30 can be converted for spectroscopy by the addition of an external objective mounted transmission grating, quite wide star-fields might be first imaged and then have selected star spectra captured. Hopefully, if we can get this bit of kit to work we will be able to work faster and smarter. 

A Seestar objective lens spectrometer using a 50 lines/mm set up will  provide lower resolution spectra than the 500 lines/mm spectrometer attached to the eyepiece end of 127mm refractor but working smarter will result in the spectral investigation of more stars! 

Both spectrometer set ups, however, work at  'low resolution'. Much more expensive equipment is required to undertake 'high resolution' spectral work which puts such activity outside JPO budgetary constraints.

What, in general terms, is the difference between the spectrum of a star and a spectral profile?

A stellar spectrum is the diffracted light from a star displaced  and spread out by wavelength (from blue to red)  in a number of bands (orders) which decrease in brightness as the orders  increase (displacement from the star increase). The spectrum is the raw image captured by the camera and visible to the eye. You will notice that spectra are created on either side of a star by the grating. More expensive gratings direct more light to one side than the other. These gratings are referred to as being 'blazed'. It is usual to work with the right hand first order spectrum when creating the spectral profile.

The spectral profile is a graph of the intensity of the spectrum's light (photon counts by the camera sensor) (plotted on the Y axis) plotted against wavelength ( x axis). The profile is derived from the spectrum which requires careful calibration and processing. At the JPO we have traditionally used bright stars such as Vega in the constellation Libra, which have strong Hydrogen absorption lines, for calibration of target stars under investigation. For processing the spectral profile we use the excellent software BASS Project 1.9.9.

 https://britastro.org/2017/guide-to-processing-spectra-using-the-bass-software

The useful information relating to a star is derived from the  spectral profile. A profile may be best obtained from a black and white spectrum and for this reason our 500 lines/mm. spectrometer uses a mono QHY5-11 camera.   The Seestar S30 by default captures colour datas.

What "low resolution" in stellar spectroscopy means

A low-resolution spectrum is one where fine details in the spectrum are blurred together. Instead of seeing very sharp, narrow absorption lines, you mostly see broad dips and bumps in the rainbow of starlight. So, you don’t get fine chemical fingerprints, but you do still capture the overall shape and large spectral features.

What we can learn from low resolution spectral profiles:

• Stellar temperature (the star’s “color” in detail)

The overall slope of the spectrum tells us how hot the star’s surface is.

Hot stars (like O and B types) peak in the blue/ultraviolet, while cool stars (K and M types) peak in the red/infrared.

Even at low resolution, the shape of the spectrum across visible light gives a good estimate of the star’s effective temperature.

• Spectral type and classification

Big molecular bands (e.g., TiO in cool M-type stars) or hydrogen Balmer lines (prominent in A-type stars) are broad enough to show up even in low resolution.

That lets astronomers assign a star to a spectral class (O, B, A, F, G, K, M).

• Surface gravity (giants vs dwarfs)

The strength and width of certain broad features are sensitive to whether a star has high gravity (main sequence dwarf) or low gravity (giant or supergiant).

For instance, pressure broadening is stronger in dwarfs, so hydrogen or calcium features look different.

• Metallicity in broad strokes

While you can’t measure detailed abundances, the overall strength of metal absorption blends can suggest whether a star is “metal-poor” (like in old halo stars) or “metal-rich” (like stars in the disk).

Extremely metal-poor stars stand out because their spectra look much smoother.

• Reddening and interstellar dust

Comparing the expected spectral shape (from the star’s type) to the observed shape tells how much starlight has been reddened by dust.

This helps estimate extinction and distance effects.

• Radial velocity (roughly, if the resolution is not too low)

At very low resolution, Doppler shifts are hard to measure precisely.

But with moderate low-res data (say R ~ 1000), you can still detect bulk shifts of broad features to see if a star is moving toward or away from us at tens of km/s accuracy.

• Special features or stellar activity

Strong emission lines (like H-alpha) show up even at low resolution.

This can reveal things like chromospheric activity, accretion (in young stars), or stellar winds.

What you cannot do with low resolution spectral profiles:

You can’t measure fine chemical abundances (like “this star has 0.2 times the Sun’s iron content”).

You can’t detect narrow line profiles that reveal rotation, turbulence, or precise radial velocities.

You can’t see isotopic ratios or subtle line blends.

Why low resolution spectroscopy is still powerful:

Even though it blurs the details, low-resolution spectroscopy is fast and efficient. Large surveys (like SDSS or LAMOST) have gathered millions of low-res spectra, which let us classify stars, map stellar populations across the Milky Way, and study galactic evolution.

So, in summary: 

Low-resolution spectroscopy can reliably tell you a star’s temperature, general spectral type, luminosity class, approximate metallicity, effects of dust, and presence of strong emission features. It gives a broad but still very physical picture of the star, even if the fine chemical “fingerprints” are lost.

 We are now ready to test the prototype and await a clear night to undertake first light for this home-made bit of kit". - Karl Segin outreach coordinator at the Jodrell Plank Observatory.

Pickering's Triangle and the Witch's Broom Nebulae in the Constellation Cygnus

 

Pickering's Triangle and the Witch's Broom Nebulae.
Seestar S30 in EQ mode. 60x60sec subs with LP filter.
Image Credit: Pip Stakkert Jodrell Plank Observatory, August 2025.

Stars removed from the image to better show the nebulae.
Pickering's Triangle lower left, Witch's Broom top right.
Image Credit: Pip Stakkert. JPO.

A more subtle re-process of the data to bring out the full range
of colours and detail in the nebulosity
and a reduction in the number of stars highlighted.
- Kurt's favourite.

"Pickering's Triangle and the Witch's Broom are constituent parts of the 'Veil Nebula' aka the 'Cygnus Loop'. Together, the parts represent the aftermath of a  supernova, which occurred between 5,000 and 10,000 thousand years ago in the constellation Cygnus the Swan. The very apparent bright star appearing to ride on the back of the Witch's Broom (Western Veil) Nebula is 52 Cygni, this star is a foreground star and is much nearer to us than the Veil Nebula" - Joel Cairo CEO of the Jodrell Plank Observatory.

"So what happened to the progenitor star?

A massive star (about 12–15× the Sun’s mass) in Cygnus ran out of nuclear fuel and underwent a core-collapse supernova. Its expanding shock front is what we see today as the Cygnus Loop/Veil Nebula, ~725 ± 15 pc (~2,370 ly) away. Despite many searches, no compact remnant (neutron star/pulsar) has been securely identified in the remnant—there’s only an unconfirmed pulsar-wind-nebula candidate in the southern 'blowout'. 

So where might be the original explosion point (“center”) ?

Astronomers often use the Loop’s geometric center as the supernova site. A recent wide-field study places that center at RA 20ʰ 50ᵐ 51ˢ, Dec +30° 34′ 06″ (J2000)—roughly midway between the Western Veil (NGC 6960) and Eastern Veil (NGC 6992/6995)". - Kurt Thrust current Director of the Jodrell Plank Observatory.

" Many of our readers have emailed me at the JPO enquiring as to the health of our neighbour, Mr Schrodinger's  cat. 

'Comet the cat' has been absent from the grounds of the JPO for some time, but we are very pleased to say, that during the recent warm spell of weather, here in Lowestoft,- she has taken up residence in a sunny spot just under the LVST antenna. Very much like the JPO's sponsors, Anita and George Roberts, Comet is getting on a bit, but she and her tail are still very much an integral part of the Observatory Team". - Karl Segin outreach coordinator at the JPO.

A fine 'Astro - Puss' indeed.

Meteors - 23:00 to 1:00 bst - 12 -13 August 2025

 

Meteors captured over 2 hours, seen against the majesty
of the Milky Way running through Cygnus.
Taken with the Canon 600d DSLR
with a Sigma wide angle lens at f =15mm.
all mounted on Star Adventurer EQ mount.
Credit: Kurt Thrust

"The Perseid meteor shower was expected to peak on the 12th of August, so the JPO team were out meteor watching for about 2 hours. In that time we spotted about 10 meteors. The Moon was just past full and made meteor observation, photography and post capture image processing difficult. Kurt set up the Observatory mini-rig with our old Canon DSLR and we all hoped for the best. The above compilation image was processed by Kurt and shows six  meteors of which two are possibly Geminids and the rest either Delta Aquarids or sporadic meteors. The two very bright stars are Deneb and Vega.".  - Joel Cairo CEO of the Jodrell Plank Observatory.

"On warm August nights, the Perseid meteor shower fills the sky with swift, bright streaks of light, each one seeming to spill from the constellation Perseus. These meteors are tiny fragments shed long ago by the comet Swift–Tuttle, which swings around the Sun every century and a bit, leaving a dusty trail in its wake. As Earth plows through this trail, the particles strike our atmosphere at nearly 59 kilometers per second, burning up in a brief, brilliant flash. Many leave behind glowing trails that linger for a moment before fading. Around the 12th and 13th of August, the display is at its best, sometimes producing more than a hundred meteors an hour under dark skies.

By late July, another, quieter shower has already been at work: the Delta Aquarids. These meteors seem to fan out from the “water jar” of Aquarius and are gentler, slower streaks than the Perseids. They most likely come from the remains of Comet Machholz, though astronomers are not entirely certain. Drifting into the atmosphere at about 41 kilometers per second, they tend to be fainter, with a steadier, more ghostlike appearance. Their peak comes around the 28th to 30th of July, when in the right location, perhaps twenty meteors an hour might be seen. They may be seen until about the 15th of August and there is an overlap with the Perseid shower.

Even when no shower is active, the sky offers its own small surprises. On any given night, a patient watcher might see a handful of sporadic meteors — lone flashes from random directions. These are the wandering dust and pebbles of the Solar System, leftovers from shattered comets, broken asteroids, and drifting interplanetary debris. Some arrive lazily, skimming the atmosphere at just over 11 kilometers per second, while others come screaming in at more than 70. They are unpredictable, unscripted visitors, making each one feel like a small gift from space". - Karl Segin outreach officer at the Jodrell Plank Observatory.

Just showing two Perseids
and a different rendition of the Milky Way stars.

Messier 33 - The Triangulum Spiral Galaxy.

 

Messier 33, NGC 598. The Triangulum Galaxy.
 Seestar S30 from the Jodrell Plank Observatory.
Image Credit: Kurt Thrust.

Messier 31, The Andromeda Galaxy,
Image Credit: Pip Stakkert

"Towards the end of a long night collecting data for the emission feature NGC7000 in the constellation Cygnus, I decided to point the Seestar S30 at the relatively nearby Triangulum Spiral Galaxy. By this time the JPO team members were all very tired, so only 30x60sec sub exposures for post acquisition stacking were obtained before we all went to bed at 3:45am. I was pleasantly surprised how well the Seestar performed on this small, relatively faint galaxy in our local galaxy group. M33 was one of the first spiral galaxies our sponsor George Roberts imaged and processed, all with the help of Olly Penrice at his Observatory in France" - Kurt Thrust current Director of the Jodrell Plank Observatory.

Comparative Study of the Spiral Galaxies in the Local Group with Emphasis on the Triangulum Galaxy (M33) by Kurt Thrust and visiting astrophysicist Professor G.P.T. Chat.

Abstract

The Local Group contains more than 50 galaxies, yet only three are large spirals: the Milky Way, Andromeda (M31), and the Triangulum Galaxy (M33). While the Milky Way and Andromeda dominate in mass and stellar content, M33 represents a smaller, less massive, but dynamically intriguing member of the trio. This report compares their structural properties, stellar populations, star formation rates, and dynamic interactions, highlighting M33’s distinct role in the Local Group.

1. Introduction

Spiral galaxies, with their iconic disk-and-arm structures, are key laboratories for studying galactic dynamics, star formation, and cosmic evolution. Within our Local Group — a gravitationally bound association extending over ~10 million light-years — only three prominent spirals exist. The Milky Way and Andromeda are massive, metal-rich systems with prominent bulges, while M33 is a smaller, late-type spiral with no significant bulge and an unusually high rate of ongoing star formation for its size. Studying M33 alongside its larger counterparts provides insight into how spiral galaxies evolve across the mass spectrum.

2. General Characteristics

Property	Milky Way	Andromeda (M31)	Triangulum (M33)
Galaxy Type	SBbc (barred spiral)	SA(s)b (unbarred spiral)	SA(s)cd (unbarred spiral)
Approx. Diameter	~100,000 ly	~220,000 ly	~60,000 ly
Stellar Mass	~6 × 10¹⁰ M☉	~1 × 10¹¹ M☉	~5 × 10⁹ M☉
Total Mass	~1.0–1.5 × 10¹² M☉	~1.5–2.0 × 10¹² M☉	~5 × 10¹¹ M☉ (upper limit)
Distance from Earth	— (we are inside)	~2.54 Mly	~2.73 Mly
Bulge Size	Prominent	Prominent	Minimal
Star Formation Rate	~1–3 M☉/yr	~0.5–1 M☉/yr	~0.5–0.7 M☉/yr

3. Structural and Morphological Differences

M33’s classification as an SA(s)cd spiral denotes a loosely wound arm structure and the absence of a central bar or significant bulge. This contrasts with the Milky Way’s intermediate barred spiral form and Andromeda’s more tightly wound, grand-design arms. M33’s disk is dominated by star-forming regions, notably NGC 604, one of the largest known H II regions in the Local Group, whereas the Milky Way and Andromeda host a mix of older stellar populations concentrated toward their bulges.

4. Stellar Populations and Metallicity

Metallicity trends reflect a galaxy’s evolutionary history. Both the Milky Way and Andromeda exhibit higher metallicities due to prolonged star formation and merger histories. M33’s metallicity is comparatively lower, suggesting less enrichment by successive generations of stars. This makes M33 a valuable analog for studying conditions in intermediate-redshift galaxies, where chemical enrichment was still incomplete.

5. Star Formation and Gas Content

Despite its smaller mass, M33 has a vigorous star formation rate relative to its size. Its interstellar medium is rich in neutral hydrogen (HI) and molecular gas, providing raw material for ongoing stellar birth. The Milky Way and Andromeda, though more massive, have lower star formation rates relative to their stellar masses, reflecting more mature stellar populations and somewhat depleted gas reservoirs.

6. Dynamics and Interactions in the Local Group

The gravitational relationships among the three spirals are complex. The Milky Way and Andromeda are on a collision course, expected to merge in about 4–5 billion years. M33 is gravitationally bound to Andromeda and may be interacting tidally with it, as suggested by distortions in its outer gas disk. Such interactions may enhance M33’s star formation activity. Observations of its proper motion indicate a dynamic orbital history within the Local Group, potentially influencing its structure.

7. M33 in Context

M33 occupies an intermediate role: more massive and structured than dwarf irregulars, yet less evolved and less massive than its giant spiral neighbors. Its lack of a dominant bulge and its high gas fraction suggest a relatively quiet merger history, possibly preserving features of early disk formation. These properties make M33 an important comparative benchmark for understanding spiral galaxy evolution across a range of environments and masses.

8. Conclusions

The Milky Way, Andromeda, and Triangulum galaxies represent a spectrum of spiral galaxy properties within a shared gravitational environment. M33 stands out as a late-type, low-mass spiral with high star-forming efficiency, a modest metallicity, and minimal central bulge. By studying M33 in relation to its larger counterparts, astronomers can better understand the scaling of galactic structure, the interplay between environment and star formation, and the evolutionary pathways of spiral galaxies.

NGC 7000 from Suffolk on a clear and steady night in August 2025

 

NGC7000 in Cygnus - Seestar S30 with LP filter
from the Jodrell Plank Observatory.
Credit{ Pip Stakkert at the JPO.

" The emission nebula Ngc 7000 (in the constellation Cygnus the Swan) is a true summer highlight in the Northern Hemisphere. The Seestar integral 'light pollution filter' is a dual narrow band filter and so Pip Stakkert processed the data as a modified RGB SHO image". - Joel Cairo CEO of the Jodrell Plank Observatory. 

NGC 7000: The North America Nebula in the Constellation Cygnus

An overview by visiting astrophysicist Professor G.P.T. Chat and Kurt Thrust JPO Director.

In the rich star fields of the constellation Cygnus, not far from the bright star Deneb, lies one of the most distinctive emission nebulae in the night sky—NGC 7000, better known as the North America Nebula. This vast cloud of ionised hydrogen, catalogued as Sharpless 117 and Caldwell 20, owes its popular name to the remarkable resemblance of its silhouette to the outline of the North American continent. Its apparent proximity to Deneb, combined with its immense angular size—roughly two degrees by 1.6 degrees, more than four times the diameter of the full Moon—marks it as a prominent yet elusive target for observers. Despite an integrated visual magnitude of about 4.0, its low surface brightness makes it difficult to discern without dark skies and the aid of wide-field optics or nebular filters.

Scientific measurements place NGC 7000 at a distance of approximately 2,590 ± 80 light-years (795 ± 25 parsecs) from Earth, based on Gaia astrometry. Earlier estimates, derived from photometric and spectroscopic methods, had suggested a range of 1,600 to 1,800 light-years. At this greater distance, its physical size is striking—nearly 100 light-years across, with the central regions alone spanning tens of light-years. The nebula forms part of a much larger H II region known as Sh2‑117, which also encompasses the neighbouring Pelican Nebula (IC 5070). Between the two lies the dark molecular cloud L935, a dense lane of interstellar dust that obscures visible light but becomes transparent at infrared and radio wavelengths.

The distinctive glow of NGC 7000 is a product of ionisation: ultraviolet photons from nearby hot, massive stars strip electrons from hydrogen atoms in the nebula, causing them to recombine and emit light, particularly in the hydrogen-alpha (Hα) wavelength. While several stars contribute to this process, the dominant ionising source is thought to be the O-type binary HD 199579, sometimes called “Miro’s Diamond.” The energy output from these stars not only illuminates the nebula but also sculpts its internal structure through stellar winds and radiation pressure.

One of the most active regions within NGC 7000 is the so-called “Cygnus Wall,” a dense ridge of gas and dust corresponding to the Gulf of Mexico and Florida in the nebula’s continental outline. This region, about 15–20 light-years long, is a site of intense star formation. Observations in the infrared and radio have revealed hundreds of young stellar objects (YSOs), along with Herbig–Haro objects and molecular outflows. The kinematics of the gas, mapped through molecular line spectroscopy, show velocities consistent with a turbulent molecular cloud undergoing collapse, with some subregions expanding at rates of 0.3–0.5 km/s per parsec. The inferred ages of these stellar populations, often in the range of one to ten million years, suggest a dynamic history of triggered star formation driven by feedback from earlier generations of massive stars.

Historically, NGC 7000 was first recorded by William Herschel in 1786, who described it as a “faint, extremely large, diffuse nebulosity.” John Herschel later added it to his catalogue, but its true shape and extent were only revealed through astrophotography. In 1890, the German astronomer Max Wolf captured an image that clearly showed its resemblance to North America, a name that has endured in both amateur and professional literature.

Today, the North America Nebula is a favourite subject of astrophotographers, who capture its red Hα glow in exquisite detail using long exposures and narrowband filters. For visual observers, it offers a more subtle challenge, rewarding those under dark, moonless skies with binoculars or wide-field telescopes. The faint nebulosity is best appreciated with the aid of a UHC or Hα filter, which enhances contrast by suppressing background light.

Beyond its aesthetic appeal, NGC 7000 is of considerable astrophysical interest. As one of the nearest massive H II regions, it provides an accessible laboratory for studying the processes of molecular cloud evolution, star cluster formation, and the feedback effects of massive stars. Gaia’s precise distance and motion data, combined with multiwavelength imaging and spectroscopy, are helping astronomers trace the complex interplay of gas dynamics, stellar winds, and triggered star formation in this part of the Milky Way. In the sweep of the northern summer sky, the North America Nebula stands not just as a celestial landmark, but as a vivid example of the forces that shape our galaxy.

Table 1 – Astrophysical Parameters of NGC 7000 (North America Nebula)

Parameter	Value	Notes
Catalogue Designations	NGC 7000, Sh2‑117, Caldwell 20	Part of Cygnus molecular cloud complex
Common Name	North America Nebula	Named for resemblance to North American continent
Constellation	Cygnus	Near bright star Deneb (α Cygni)
Right Ascension (J2000)	20h 59m 17.1s	Central coordinates
Declination (J2000)	+44° 31′ 44″	Central coordinates
Distance	2,590 ± 80 ly (795 ± 25 pc)	Gaia-based estimate; earlier values ~1,600–1,800 ly
Apparent Magnitude (V)	~4.0–4.5	Low surface brightness; best seen with filters
Angular Size	120′ × 100′ (~2° × 1.6°)	Over 4× the full Moon
Physical Size	~90–100 ly across	Estimated from angular size and distance
Dominant Ionising Source	HD 199579 (O-type binary)	Likely primary UV source
Associated Regions	IC 5070 (Pelican Nebula), L935 dark cloud	Separated by dust lane
Notable Features	Cygnus Wall, “Gulf of Mexico”	Dense star-forming ridges
Star Formation Activity	Hundreds of YSOs, Herbig–Haro objects, molecular outflows	Ages ~1–10 Myr
Discovery	William Herschel, 1786	Described as faint and large
Photographic Recognition	Max Wolf, 1890	First to capture shape
Best Viewing Season	Northern Hemisphere, July–September	Best under dark skies with UHC/Hα filters

'The Wall'
- cropped enlargement from the above widefield image:
Credit: Kurt Thrust.