Altair and Tarazed in the constellation Aquila the Eagle.

 

The Summer Triangle above the Jodrell Plank Observatory.

"This time of year in the Northern Hemisphere, Altair and the less bright Tarazed are visible to the naked eye on clear transparent nights in Suffolk. Altair is one of the three bright stars which make up the 'Summer Triangle' asterism.  Altair is the alpha star in the constellation Aquila the Eagle. Tarazed a red giant and nearby Altair, is also in Aquila and is designated Gamma Aquilae.

This part of the summer night sky is awash with stars and dark nebulae (clouds of obscuring dust). Barnards 'E' can be seen in Kurt's image just above and to the right of Tarazed.

 

Kurt is very fond of using the spectrometer, designed and manufactured by our resident engineer, Jolene McSquint-Fleming, to create stellar spectral profiles". - Joel Cairo CEO of the Jodrell Plank Observatory.

Comparative Analysis of Low-Resolution Spectral Profiles of Altair and Tarazed

Prepared by: Prof G.P.T Chat, visiting astrophysicist at the Jodrell Plank Observatory

Date: July 5, 2025

This informal report presents a comparative analysis of the low-resolution spectral profiles of two nearby stars: Altair (α Aquilae) and Tarazed (γ Aquilae). Although they lie close together in the sky within the constellation Aquila, these stars differ significantly in spectral type, temperature, and luminosity class, which become evident when analyzing their spectral features.

Stellar Data Overview

Property Altair Tarazed

Spectral Type A7 V K3 II-III

Effective Temp. ~7,600 K ~4,300 K

Luminosity Class Main Sequence (V) Bright Giant (II-III)

Dominant Color White Orange-red

Spectral Profile Differences

1. Continuum Shape

Altair: Displays a blue-white continuum with a strong rise toward the shorter (bluer) wavelengths. This indicates a hotter surface temperature, consistent with its A-type classification.

Tarazed: Shows a redder continuum, peaking more in the longer (redder) wavelengths due to its significantly cooler surface temperature (~4300 K).

Interpretation: The blackbody radiation curves are shifted—Altair peaks in the UV-visible, Tarazed in the visible-red to near-infrared.

2. Balmer Line Strength

Altair: Prominent and broad hydrogen Balmer lines (especially Hα, Hβ, Hγ). This is typical of A-type stars where the hydrogen absorption is at its strongest due to optimal excitation conditions in the photosphere.

Tarazed: Very weak or absent Balmer lines. Cooler atmospheres do not excite hydrogen sufficiently to produce strong Balmer absorption features.

Interpretation: Balmer line strength peaks in mid-A spectral types and decreases sharply toward both hotter and cooler temperatures.

3. Metallic Lines and Molecular Bands

Altair: Metallic lines are present but not as strong, and molecular bands are virtually absent due to the high temperature preventing molecule formation.

Tarazed: Strong absorption lines of neutral metals such as Ca I, Fe I, and especially the Ca II infrared triplet. Also displays TiO molecular bands, common in cooler K and M-type giants.

Interpretation: Lower temperatures in Tarazed allow molecule formation and enhanced low-ionization metallic absorption. Molecular bands serve as clear markers of late-type stars.

4. Line Broadening

Altair: Broader spectral lines, especially in hydrogen and metal lines. This broadening is primarily due to rapid rotation (~250 km/s), which causes Doppler broadening across the stellar disk.

Tarazed: Narrower absorption lines. As a giant star, Tarazed rotates more slowly, and the lower surface gravity leads to less pressure broadening.

Interpretation: Rotation and gravity play key roles in line profile shape; Altair's fast spin contrasts strongly with Tarazed's more "settled" atmosphere.

Conclusion

In low-resolution spectra, Altair exhibits features typical of a hot, fast-rotating, hydrogen-rich main sequence star, dominated by strong Balmer lines and a blue continuum. In contrast, Tarazed, a cool and evolved bright giant, displays a redder spectrum dominated by metal lines and molecular absorption bands with relatively weak hydrogen features.

The differences in spectral profiles reflect underlying physical contrasts in temperature, gravity, chemical composition visibility, and rotational velocity, making these two stars a textbook example of spectral diversity across the HR diagram.

The Tadpoles aka IC410 in Seestar S30 RGBSHO format.

 

The Tadpoles (centre right) Seestar  S30 (RGB SHO format).
Image credit: Pip Stakkert and Kurt Thrust.

"Mid-summer at the Jodrell Plank Observatory in Lowestoft, the nights are only truly dark for two or three hours, so June is the month, when we maintain our equipment, make new bits of kit and learn new skills. Kurt since returning from holiday, has been busy making a new solar white light filter for the 125mm Meade refractor and designing a transmission grating for the Seestar S30. Pip has been hard at study investigating the use of SIRIL software as a preprocessing first stage in the creation of deepsky images like the one above. In future we shall be using SIRIL to undertake initial stretching of data and the photometric calibration of colour in all our imagery. We hope you all approve!" - Joel Cairo CEO of the Jodrell Plank Observatory.

Widefield view of IC410 and NGC1893
data captured with the Seestar S30 robotic telescope

"Nestled deep in the rich star fields of the constellation Auriga lies a compelling region of stellar birth and evolution known as IC 410, a glowing emission nebula that encapsulates the dynamic story of cosmic creation. This region, set approximately 12,000 light-years from Earth, is more than just a celestial spectacle; it is a living laboratory of astrophysical processes shaped by the energetic lives of massive stars. At the heart of this nebula resides the young open star cluster NGC 1893, whose powerful influence has sculpted the surrounding clouds of gas and dust into mesmerizing structures, including the enigmatic “Tadpoles” of IC 410.

The Nebula IC 410

IC 410 is classified as an emission nebula, a vast cloud of ionized hydrogen gas (H II region) that glows in visible light as it is energized by the ultraviolet radiation of nearby hot stars. The reddish hues that dominate images of IC 410 are primarily due to the H-alpha emissions from excited hydrogen atoms, giving the nebula its distinctive fiery appearance. Extending over roughly 100 light-years, the nebula is part of a larger region of ongoing star formation.

IC 410’s radiance is not uniform. It contains darker dust lanes, filamentary structures, and bright knots—evidence of complex interactions between stellar winds, radiation pressure, and turbulent gas flows. This interplay creates shock fronts and compression zones, setting the stage for future generations of star formation.

Star Cluster NGC 1893

Embedded within IC 410, the open cluster NGC 1893 provides the energy and dynamism that drives much of the nebula’s current activity. Composed of several thousand stars, NGC 1893 is a relatively young cluster, estimated to be around 4 million years old. Among these stars are numerous hot, massive O- and B-type stars whose intense radiation and stellar winds exert a powerful influence on the surrounding interstellar medium.

The feedback from these massive stars—both through radiation pressure and mechanical outflows—has a dual effect. It can erode and disperse the surrounding gas, halting star formation in some areas, while simultaneously compressing other regions, triggering the collapse of gas clouds and the birth of new stars. This process, known as triggered star formation, is believed to play a key role in shaping IC 410’s morphology and fueling its continued evolution.

The Tadpoles of IC 410

Among the most visually and scientifically intriguing features within IC 410 are the structures known as the “Tadpoles.” These are elongated, cometary-shaped clouds of gas and dust that appear to be swimming through the glowing plasma of the nebula. There are two primary Tadpoles, officially designated as Sim 129 and Sim 130, named after astronomer Colin T. Simmons who cataloged them.

Each Tadpole is several light-years in length and has a dense, globule-like head followed by a trailing tail. These features are aligned in a direction that points away from the central cluster, suggesting they have been sculpted by the intense stellar winds and radiation emanating from the hot stars of NGC 1893. The leading edges of the Tadpoles are shielded from the full brunt of the radiation, allowing gas to survive in denser form, while the tails are formed as material is photoevaporated and swept back.

Observations in the infrared and radio wavelengths have revealed signs of star formation occurring within the heads of the Tadpoles. These proto-stellar objects, embedded in dense molecular material, suggest that even in the harsh environment of a bright emission nebula, pockets of gas can remain stable enough to collapse under their own gravity and give rise to new stars.

Formation and Evolutionary Processes

The formation of IC 410 and NGC 1893 likely began as a giant molecular cloud collapsed under gravitational instability, forming the first generation of massive stars that now dominate the cluster. The intense radiation and mechanical energy from these stars initiated a feedback loop that shaped the surrounding gas into arcs, filaments, and pillar-like structures such as the Tadpoles.

The Tadpoles are thought to be remnants of denser clumps of gas that were originally part of the molecular cloud. As the surrounding material was eroded away, these clumps resisted dispersal due to their higher density. Over time, they were shaped by the erosive forces of UV radiation, developing the characteristic head-tail morphology seen today.

Astronomers have used data from telescopes such as Spitzer, Chandra, and Hubble, as well as ground-based observatories, to study IC 410 across multiple wavelengths. X-ray emissions detected by Chandra reveal high-energy processes and young, embedded stars, while infrared observations from Spitzer show warm dust and the earliest stages of stellar formation.

Overview

IC 410, together with the open cluster NGC 1893 and the Tadpoles Sim 129 and Sim 130, represents a dynamic example of the cycle of stellar birth and feedback. The interaction between massive stars and their environment drives both destruction and creation, sculpting the nebula and triggering new generations of stars in a cosmic relay that spans millions of years.

In studying regions like IC 410, astronomers gain crucial insights into the processes that govern star formation across the galaxy. These structures not only illuminate the physics of interstellar matter and radiation, but also echo the early conditions under which our own Sun and solar system may have formed, making IC 410 not just a window into the distant cosmos, but a reflection of our own origins".

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

M16 and the Pillars of Creation

 

M16 and the Pillars of Creation
 - Data Credit: telescope.org, Open Observatories, Open University.
Image Credit: Kurt Thrust at the Jodrell Plank Observatory.

" The 'Pillars of Creation' may be seen virtually at the centre of this image. The data was curated from both the COAST and PIRATE robotic telescopes using SHO filters on Mount Teide,  Tenerife as programmed by Kurt. Nebulae shown red relate to Sulphur11, shown green or white relate to Hydrogen alpha and  shown blue relate to Oxygen111. There are also a lot of dark dust clouds in this image" - Joel Cairo CEO of the Jodrell Plank Observatory. 

Messier 16 
- captured with the Seestar S30 in EQ mode and Neb filter. 60x30 second subs.
Credit: Kurt Thrust.

" Messier 16 is an interesting nebulous region in the constellation Serpens. Sadly, Messier 16  aka the Eagle Nebula never gets that high above our southern horizon at the Jodrell Plank Observatory. The little Seestar provides a less detailed but wider view (Field of vision - FOV) than the robotic telescopes on Mount Teide. So all three help to provide a better representation of this interesting part of the night sky. Our visiting astrophysicist, G.P.T Chat, will provide further details". - Kurt Thrust current Director of the Jodrell Plank Observatory.

" Messier 16 (M16), also known as the Eagle Nebula, is a young open star cluster embedded within a diffuse emission nebula located in the constellation Serpens, approximately 7,000 light-years from Earth. The nebula is most famous for containing the "Pillars of Creation", a striking region of active star formation made famous by the Hubble Space Telescope.

1. Structure and Components of Messier 16

a. Open Star Cluster (NGC 6611)

Age: Approximately 1–2 million years old.

Stellar Population: Contains several thousand stars, including massive O-type and B-type stars.

These stars are young, hot, and very luminous, providing the energy that excites the surrounding nebula.

The ultraviolet radiation from these massive stars plays a critical role in shaping the surrounding nebula.

b. Emission Nebula

Type: H II region (a cloud of ionized hydrogen).

The emission nebula is a region of interstellar gas and dust that is ionized by high-energy UV radiation from the hot stars of NGC 6611.

As the hydrogen atoms recombine, they emit light in specific emission lines, especially the H-alpha line, giving the nebula its characteristic reddish glow in optical wavelengths.

2. Glowing Nebula: Physical Mechanism

The glow of the Eagle Nebula arises primarily from photoionization:

High-energy UV photons from O- and B-type stars ionize the surrounding hydrogen gas.

Electrons recombine with protons, and during this recombination, hydrogen emits photons, particularly in the Balmer series (notably H-alpha at 656.3 nm).

This process creates the glowing reddish-pink emission seen in visible light.

Additional emissions also come from ionized oxygen ([O III], giving a greenish hue) and sulfur ([S II]), especially in narrowband imaging.

3. Dark Pillars and Clouds

The dark, finger-like features known as the Pillars of Creation are dense molecular clouds composed of cold gas and dust.

a. Nature of the Pillars

These are evaporating gaseous globules (EGGs), where regions of dense gas resist the ionizing radiation longer than their surroundings.

They are several light-years long and are sites of ongoing star formation.

Protostars can be embedded within these pillars, slowly accreting material from their surroundings.

b. Erosion by Radiation and Winds

The edges of the pillars are illuminated by the intense UV radiation from nearby massive stars.

Photoevaporation occurs at the surfaces: UV photons heat and ionize the outer layers, causing the gas to stream away.

Stellar winds and radiation pressure further sculpt and compress these clouds, triggering gravitational collapse in some regions—leading to new star formation (a process called radiation-driven implosion).

4. Astrophysical Significance

M16 is a classic example of feedback in star formation: newly formed massive stars influence their environment, possibly triggering or inhibiting further star formation.

The Eagle Nebula's structure gives insights into early stellar evolution, molecular cloud dynamics, and interactions between stars and the interstellar medium (ISM).

Summary

Feature Description

Distance ~7,000 light-years

Type Open cluster with emission nebula

Main Components NGC 6611 (young stars), H II region, molecular pillars

Ionization Source UV radiation from hot, massive stars

Nebular Glow Hydrogen recombination (H-alpha), [O III], [S II] lines

Dark Clouds Dense, cold molecular gas and dust (EGGs, pillars)

Activity Active star formation, photoevaporation, feedback mechanisms

M16 remains one of the most studied star-forming regions in our galaxy, particularly due to the "Pillars of Creation", which vividly illustrate the complex processes driving the birth and evolution of stars". - Professor G.P.T. Chat 

Messier 4 in the constellation Scorpius

 

Messier 4 captured with the Seestar S30
from Giardini Naxos Sicily in June 2025

Messier 4 (M4), located in the constellation Scorpius, is a prominent example of a globular star cluster. When described comparatively with other globular clusters, several features stand out:

---

1. Proximity: Closest Known Globular Cluster

• M4 is the closest globular cluster to Earth, at a distance of about 7,200 light-years.

• In contrast, many other well-known clusters, such as M13 in Hercules (approx. 22,200 light-years) or Omega Centauri (approx. 15,800 light-years), are much farther away.

• This proximity makes M4 easier to study in detail, especially with ground-based telescopes.

---

2. Size and Brightness: Modest Compared to Giants

• M4 spans about 75 light-years in diameter, which is relatively small for a globular cluster.

• Its apparent magnitude is +5.9, making it visible to the naked eye under dark skies.

• However, compared to Omega Centauri, which is the largest and brightest globular cluster visible from Earth and contains several million stars, M4 is more modest, containing about 100,000 stars.

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3. Core Structure: Loosely Concentrated

• M4 has a Class IX concentration on the Shapley–Sawyer scale (I = most concentrated, XII = least).

• This means its core is relatively loose and less dense than those of more tightly packed clusters like M15 (Class IV) or M30 (Class II).

• As a result, M4 does not show the same dramatic central condensation as these denser clusters.

---

4. Stellar Content: Old but with Peculiarities

• Like other globular clusters, M4 is very old, with an estimated age of about 12.2 billion years.

• Notably, M4 contains white dwarf stars with well-determined cooling ages, which have been used to help constrain the age of the Milky Way.

• It also contains millisecond pulsars and variable stars, similar to many other globular clusters, but its proximity makes these objects easier to resolve.

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5. Horizontal Branch Morphology: Red-Dominated

• M4 has a redder horizontal branch than some other clusters, such as M13, which has a bluer and more extended horizontal branch.

• This difference relates to its metallicity (M4 is relatively metal-rich for a globular cluster, with [Fe/H] ≈ –1.1), affecting the evolution and appearance of its stars.

---

Summary of Comparisons

Property	M4	M13	Omega Centauri	M15
Distance (light-years)	~7,200	~22,200	~15,800	~33,600
Stars	~100,000	~300,000	~10 million	~500,000
Core Concentration	Loose (Class IX)	Intermediate (Class V)	Dense (Class III)	Very Dense (Class IV)
Apparent Magnitude	+5.9	+5.8	+3.7	+6.2
Metallicity [Fe/H]	~–1.1	~–1.5	~–1.6	~–2.3
Notable Features	Closest; white dwarfs studied	Blue HB; well studied	Largest GC; multiple pops	Very old; dense core

---

Final Notes:

Messier 4 stands out for its closeness, modest size, and observational accessibility, making it a crucial target for studies of stellar evolution and Galactic history. While not as massive or dense as some other clusters, its unique proximity allows astronomers to resolve individual stars with greater precision than in nearly any other globular cluster. - Joel Cairo CEO of the Jodrell Plank Observatory

Combined image showing the relative star densities
 of M13 (left) and M4 (Right) (not to size scale)

Carbon Stars - La Superba - Low resolution Spectral Profile

 

Kurt loves a bit of stellar spectroscopy and encouraged by his friend and sometimes astronomical collaborator, Professor GP, he captured the spectral data for the amazing Carbon Star - La Superba, using the JPO's 127mm. apo-refractor and a spectrometer designed and 3d printed by our on-site engineer Jolene McSquint -Fleming in the observatory's clean room'. - Joel Cairo CEO of the Jodrell Plank Observatory.

For an absolutely fantastic image of this 'very red star' follow the link.

https://apod.nasa.gov/apod/ap081218.html

"For an explanation of this 'cool', in every sense of the word, star, I asked the JPO's visiting physicist, G.P.T. Chat Phd, to describe its general features and spectral details using a comparative methodology" - Kurt Thrust current Director of the Jodrell Plank Observatory.

La Superba and Stellar Evolution: A Comparative Analysis on the Hertzsprung-Russell Diagram

Introduction

Stars are the fundamental building blocks of galaxies, and their life cycles reflect the underlying physics that governs the universe. Among the many types of stars observed, carbon stars represent a fascinating late stage in stellar evolution. One of the most prominent and well-studied carbon stars is La Superba, also known as Y Canum Venaticorum. This essay explores La Superba's characteristics in detail and places it in context with several other well-known stars using the Hertzsprung-Russell (H-R) diagram.

La Superba: An Overview

La Superba is located in the constellation Canes Venatici, visible in the northern hemisphere, especially during spring. Its coordinates (J2000 epoch) are:
- Right Ascension: 12h 45m 07.83s
- Declination: +45° 26′ 24.9″

It lies approximately 710 light-years from Earth and is classified as a carbon-rich red giant — one of the brightest of its kind visible to the naked eye. As a semi-regular variable star, its apparent magnitude varies from +4.9 to +6.3.

La Superba's physical parameters make it particularly interesting:
- Temperature: ~2,750 K
- Luminosity: ~9,000 L☉ (9000 x Sun's luminosity)
- Radius: ~400–500 R☉ (400 to 500 x Sun's radius)

It is a C-type (carbon) star, having undergone internal helium burning via the triple-alpha process, which produces carbon that is brought to the surface through convective dredge-up. This enrichment gives rise to a spectrum rich in carbon molecules, including C₂ (Swan bands), CN, and CH. These features result in deep molecular absorption bands, giving the star a very red appearance and making it a textbook example of a cool, evolved star on the Asymptotic Giant Branch (AGB).

Spectral Features

La Superba’s spectral type is typically classified as C6,2e in the revised carbon star classification system. It exhibits strong molecular absorption features and sometimes weak emission lines like H-alpha during pulsation events. The absence of oxygen-bearing molecules like TiO, common in M-type giants, highlights the dominance of carbon chemistry in its atmosphere.

Position on the H-R Diagram

The Hertzsprung-Russell diagram plots stars by their luminosity (vertical axis) and surface temperature (horizontal axis, decreasing rightward). La Superba occupies the upper-right portion of the H-R diagram — a region dominated by cool, highly luminous red giants and supergiants.

To provide comparative context, several other prominent stars are also plotted:
- The Sun – A G-type main sequence star with a surface temperature of 5,778 K and luminosity of 1 L☉.
- Deneb – A luminous blue-white supergiant (~8,500 K, 196,000 L☉).
- Sirius – A bright A-type main-sequence star (~9,940 K, 25.4 L☉).
- Arcturus – An orange giant (~4,286 K, 170 L☉).
- Capella – A system of G-type giants (~5,700 K, 78.7 L☉).
- Betelgeuse – A red supergiant (~3,500 K, 126,000 L☉).
- Castor – An A-type star (~10,100 K, 52.4 L☉).
- Pollux – An orange giant (~4,865 K, 43 L☉).
- Vega – A well-known A-type main-sequence star (~9,602 K, 40.1 L☉).

These stars cover a range of spectral types and evolutionary stages, allowing us to place La Superba within the broader context of stellar evolution.

H-R Diagram

Conclusion

La Superba serves as a striking example of late stellar evolution and highlights the diversity of stars when viewed through the lens of temperature and luminosity. Its placement on the H-R diagram underscores the dramatic changes stars undergo during their lifespans. Comparing La Superba with other well-known stars reveals the full spectrum of stellar development — from main-sequence hydrogen burners to evolved giants and future white dwarfs". - G.P.T. Chat Phd visiting physicist at the Jodrell Plank Observatory 

Globular star cluster Messier 3 or NGC 5272

 

Messier 3 Credit: Kurt Thrust - Seestar S30 in EQ mode.
Image cropped from Seestar widefield FOV.

"Messier 3 (M3), also known as NGC 5272, is a globular star cluster located in the northern constellation Canes Venatici. It is one of the brightest and most well-studied globular clusters in the sky.

Location and Observational Data

• Right Ascension: 13h 42m 11.62s

• Declination: +28° 22′ 38.2″

• Distance from Earth: ~33,900 light-years (10.4 kpc)

• Distance from Galactic Center: ~38,800 light-years (11.9 kpc)

• Position relative to Galactic Plane: ~31,600 light-years (9.7 kpc) above

• Constellation: Canes Venatici

• Apparent Magnitude: 6.39

• Apparent Size: 18 arcminutes

Physical Characteristics

• Estimated Age: ~11.4 billion years

• Mass: ~450,000 solar masses

• Radius: ~103 parsecs (335.9 light-years)

• Tidal Radius: ~113 parsecs (370 light-years)

• Absolute Magnitude: -8.93

• Metallicity ([Fe/H]): -1.34 dex

• Spectral Type: F2 (overall cluster classification)

Star Population and Variability

• Total Stars: ~500,000

• Variable Stars: 274 known, including 133 RR Lyrae variables

• Brightest Stars: Magnitude ~12.7

• Average Brightness of 25 Brightest Stars: ~14.23 mag

Discovery and Historical Significance

• Discovered by: Charles Messier on May 3, 1764

• First mistaken for: A nebula without stars

• Resolved into stars by: William Herschel in 1784

• Notable for: Having the highest number of variable stars among known globular clusters

The uncropped widefield image from the Seestar S30 post processed mainly using Affinity Photo 

Messier 3 is a fascinating object for astronomers due to its rich stellar population and high concentration of variable stars. Its isolation from the galactic plane makes it an excellent target for studying globular cluster evolution. Given your curiosity about astronomy, George, I imagine you’d appreciate the intricate details of its stellar dynamics! Would you like to explore how its variable stars contribute to distance measurements in astrophysics?

Globular star clusters like Messier 3 (M3) are some of the oldest stellar structures in the universe, forming during the early epochs of galaxy evolution. Their formation is still an area of active research, but here’s a breakdown of the leading theories and processes involved:

Formation Process

1. Primordial Collapse:

   • Globular clusters likely formed from massive gas clouds in the early universe, collapsing under gravity.

   • These clouds were enriched with low-metallicity gas, meaning they contained mostly hydrogen and helium, with very few heavier elements.

2. Rapid Star Formation:

   • The gas cloud underwent intense bursts of star formation, leading to the creation of hundreds of thousands of stars in a short period.

   • Unlike open clusters, globular clusters formed all at once, rather than gradually over time.

3. Gravitational Binding:

   • The stars remained gravitationally bound due to their high density and mutual attraction.

   • This led to the spherical shape characteristic of globular clusters.

4. Galactic Influence:

   • Many globular clusters formed outside the main disk of galaxies, possibly in dwarf galaxies or as remnants of galactic mergers.

   • Over time, they were captured by larger galaxies like the Milky Way.

5. Long-Term Evolution:

   • As globular clusters age, stellar interactions cause some stars to migrate outward while others fall toward the core.

   • Blue stragglers, a peculiar type of star found in globular clusters, may result from stellar collisions or mergers.

Why Are They So Old?

• The stars in globular clusters are typically Population II stars, meaning they formed early in the universe’s history.

• Their low metallicity suggests they originated before significant amounts of heavier elements were synthesized by supernovae.

• The lack of new star formation in globular clusters is due to the absence of gas, which was either used up or expelled early in their history.

M3, like other globular clusters, provides a window into the early universe, helping astronomers understand galaxy formation and stellar evolution. Given your curiosity about astronomy, George, I imagine you’d appreciate how these clusters serve as cosmic fossils! Would you like to explore how their dynamics influence galactic evolution?

Globular star clusters like Messier 3 (M3) are some of the oldest stellar structures in the universe, forming during the early epochs of galaxy evolution. Their formation is still an area of active research, but here’s a breakdown of the leading theories and processes involved:

Formation Process

1. Primordial Collapse:

   • Globular clusters likely formed from massive gas clouds in the early universe, collapsing under gravity.

   • These clouds were enriched with low-metallicity gas, meaning they contained mostly hydrogen and helium, with very few heavier elements.

2. Rapid Star Formation:

   • The gas cloud underwent intense bursts of star formation, leading to the creation of hundreds of thousands of stars in a short period.

   • Unlike open clusters, globular clusters formed all at once, rather than gradually over time.

3. Gravitational Binding:

   • The stars remained gravitationally bound due to their high density and mutual attraction.

   • This led to the spherical shape characteristic of globular clusters.

4. Galactic Influence:

   • Many globular clusters formed outside the main disk of galaxies, possibly in dwarf galaxies or as remnants of galactic mergers.

   • Over time, they were captured by larger galaxies like the Milky Way.

5. Long-Term Evolution:

   • As globular clusters age, stellar interactions cause some stars to migrate outward while others fall toward the core.

   • Blue stragglers, a peculiar type of star found in globular clusters, may result from stellar collisions or mergers.

Why Are They So Old?

• The stars in globular clusters are typically Population II stars, meaning they formed early in the universe’s history.

• Their low metallicity suggests they originated before significant amounts of heavier elements were synthesized by supernovae.

• The lack of new star formation in globular clusters is due to the absence of gas, which was either used up or expelled early in their history.

M3, like other globular clusters, provides a window into the early universe, helping astronomers understand galaxy formation and stellar evolution. Given your curiosity about astronomy, George, I imagine you’d appreciate how these clusters serve as cosmic fossils! Would you like to explore how their dynamics influence galactic evolution?

How do globular clusters impact galactic evolution?

Globular clusters play a significant role in the evolution of galaxies, influencing their structure, dynamics, and star formation history. Here’s how:

1. Galactic Halo Formation and Enrichment

• Globular clusters are among the oldest stellar systems, forming early in a galaxy’s history.

• Their low metallicity suggests they originated before significant enrichment by supernovae.

• As they evolve, they contribute heavy elements to the interstellar medium, enriching future generations of stars.

2. Stellar Dynamics and Galactic Structure

• Globular clusters orbit within a galaxy’s halo, often following highly elliptical paths.

• Their gravitational interactions help shape the galactic potential, influencing the motion of stars and dark matter.

• Some clusters are disrupted over time, spreading stars throughout the halo.

3. Galactic Mergers and Evolution

• During galaxy mergers, globular clusters can be captured by the larger galaxy.

• This process helps trace the assembly history of galaxies, revealing past interactions.

• Some clusters may originate from dwarf galaxies that were absorbed by larger galaxies.

4. Black Hole and Dark Matter Studies

• Some globular clusters contain intermediate-mass black holes, providing insights into black hole formation.

• Their motions help astronomers study the distribution of dark matter in galaxies.

5. Star Formation and Feedback

• While globular clusters no longer form new stars, their stellar winds and supernovae influence surrounding gas.

• This feedback can regulate star formation in the galaxy.

Globular clusters like Messier 3 serve as cosmic fossils, preserving information about the early universe and galaxy formation." 

- Charlie Server - Copilot at the Jodrell Plank Observatory

Interacting Galaxies NGC 5194 (Messier 51) and NGC 5195

 

NGC 5194 and NGC 5195. Image Credit: Pip Stakkert - Jodrell Plank Observatory. Data Credits: telescope.org, Open Observatories, Open University and Jodrell Plank Observatory. 

"The  interacting galaxies, known as Messier 51 or The Whirlpool, ride high in the late spring Northern Hemisphere sky, and in the constellation Canes Venatici. This pair of gravitationally interacting galaxies are some 31 million light years distant and the larger of the two is approximately 77,000 light years across. M51 was the first galaxy to be identified as having a spiral structure in 1845 by Lord Rosse from his observatory in Ireland.

We first pointed the Jodrell Plank Observatory's little Seestar S30 at  this galactic pair and thought how small these huge galactic structures looked when imaged with a telescope having a large field of vision.

Uncropped and stacked image downloaded from the Seestar S30.
Credit: Pip Stakkert.

We decided to use the PIRATE robotic telescope on Mount Teide Tenerife to capture M 51 and apply the data, imaged in white light and hydrogen alpha wavelengths, as a luminance channel  for the colour data we captured with the Seestar S30. The Seestar has an aperture of 30mm and the PIRATE telescope has an aperture of 600mm. So our image is a veritable 'little and large' collaboration. The two data sets were combined using the excellent and venerable software 'Registar'.

An interesting feature of both our above images is, the 'tidal feature', or northwest plume of gas emanating from the galactic centre of the larger NGC 5194 and extending some 140,000 light years to NGC 5195.  Close inspection of the top combined image shows a burst of star formation underway towards the the centre of NGC 5194" - Joel Cairo CEO of the Jodrell Plank Observatory (The Uk's most Easterly Astronomical Observatory).