Messier 3 - New Data and revised data processing methodology.

 

Messier 3 - Globular star Cluster
in the Constellation Canes Venatici.
Seestar S30 in Eq mode.  1 min x 60 subs
Credit: Kurt Thrust at the JPO. 

" Our dedicated team of imagers and data processors has been experimenting with the application of the astro-freeware SIRIL and has used it to good affect in increasing the dynamic range of the M3 data captured on a clear night from the JPO in May this year. 'There is gold in them there 'data reduction' hills'" - Joel Cairo CEO of the Jodrell Plank Observatory.

"These images present the globular star cluster M3 — also catalogued as Messier 3 — suspended against a richly populated stellar background in the constellation Canes Venatici. Captured with a Seestar S30 smart telescope from the grounds of the Jodrell Plank Observatory under the direction of Kurt Thrust, the observation reveals one of the Milky Way’s most celebrated globular clusters: a gravitationally bound sphere containing roughly half a million ancient stars compressed into a region only a few hundred light-years across.

At a distance of approximately 34,000 light-years from Earth, M3 appears as a concentrated stellar nucleus whose luminosity rises sharply toward an intensely radiant core. The cluster's structure is immediately apparent: a dense central condensation surrounded by progressively looser stellar populations that dissolve into the surrounding galactic field. This radial distribution is the visible signature of a system that has remained gravitationally bound for more than eleven billion years, surviving countless passages through the Milky Way's halo while preserving a fossil record of the Galaxy's earliest epochs.

The warm golden and reddish tones scattered throughout the cluster arise predominantly from evolved red giant stars nearing the final stages of stellar evolution. Intermixed among them are hotter blue-white stars, including the enigmatic "blue stragglers" that appear younger than the rest of the cluster population. Their presence suggests a dynamic environment where close stellar encounters, mergers, and mass transfer events continue to reshape individual stars despite the cluster's immense age.

M3 is particularly significant to modern astrophysics because it hosts an extraordinary population of variable stars, including a large number of RR Lyrae variables whose rhythmic pulsations provide a fundamental rung on the cosmic distance ladder. These stars act as standard candles, enabling astronomers to measure distances across the Milky Way and beyond with remarkable precision. More variable stars have been identified in M3 than in almost any other known globular cluster, making it a natural laboratory for studies of stellar evolution and pulsation physics.

The Seestar S30 image demonstrates how modern compact smart telescopes can resolve individual members of a globular cluster once accessible only to larger observatory-class instruments. The cluster's sparkling granularity is evident across the halo, where hundreds of individual stars emerge from what appears visually as a diffuse cloud. Each point of light represents a sun in its own right, collectively tracing a nearly spherical stellar ecosystem orbiting far above the plane of the Milky Way.

Seen in this observation, M3 is not merely a beautiful celestial object but a relic from the early Universe: an ancient stellar metropolis whose stars formed when the Milky Way itself was still young. The image captures a moment in an ongoing cosmic history spanning billions of years, preserving within a single frame both the elegance of gravitational order and the immense scale of galactic time". Professor G.P.T Chat visiting Astrophysicist at the Jodrell Plank Observatory.

Nucleus M3 - Image Credit: night-sky/hubble-messier-catalog

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.

Messier 3 -Globular Star Cluster in the Constellation Canes Venatici

 

Messier 3 imaged using the Seestar S30 with IR cut filter.
from the Jodrell Plank Observatory. Image credit: Kurt Thrust

" Messier 3 is a globular star cluster which may be viewed from the Northern Hemisphere using binoculars or a small telescope from a dark location. Its foot-print upon the night sky is both small and dim!

In reality, M3 is a spherical gravitational grouping of 500,000 stars. approximately 670 light years in diameter. It is located towards the edge of the Milky Way Galaxy some 34000 light years distant from Earth. Many of the stars are ancient and shine strongly at red wavelengths. The cluster is thought to be over 11 billion years old  which is a large proportion of the estimated existence of the known Universe.

The JPO team were astonished by how well the tiny Seestar S30 with its 30mm aperture lens system was able to resolve stars towards the centre of M3. Quite extraordinary!

Pip Stakkert is currently working upon processing data from last night where we used the Seestar to capture a mosaic multi-pane image of the Markarian Chain of Galaxies in Virgo" - Carl Segin Outreach Coordinator at the Jodrell Plank Observatory.

Uncropped version of Seestar S30 - M3

Re-process with
more stars and Ha

M3 captured using the Seestar S30 in EQ Mode.
Credit: Kurt Thrust.

Credit: Astrometry.net

Messier 3 in the constellation Canes Venatici

The Globular Star Cluster Messier3 - 127mm Meade Apo refractor and Canon 600d DSLR. A cropped stack of 30 second sub frames. Credit Kurt Thrust at the Jodrell Plank Observatory.

 " Sadly and over the past few days, the Observatory Team has been laid low by the Covid virus. However, on a positive note , Pip Stakkert has risen from his sick bed to upgrade some of the processing software used here at Jodrell Plank. He is a particularly plucky and persistent processor indeed!

Pip has installed the latest iteration of AstroSharp, which now installs with AstroClean. Initial tests on the above image of Messsier3 have shown a big improvement over the original image.

Also, good friend of the Observatory, Professor Chrissy H Roberts, has applied some AI magic to our processing 'schstick' which improved the colour and number of stars visible in the above image. 

We are already to go and catch some night time photons with both kit and software primed for action. We just need the Covid virus to burn itself out and the weather to be astro-imaging friendly.

Messier 3 is an absolutely splendid globular star cluster some 32600 lightyears from Earth and roughly the same distance above the disc of the galactic plane of the Milky Way. It is estimated to be over 11 billion years old and contains approximately 500,000 stars. It is relatively bright and can be seen as an unresolved cloud through binoculars. To resolve stars requires a telescope with an aperture in excess of 100mm. To provide scale, the brightly illuminated dense core in our image is approximately 11 light years in diameter. The average spectral type of the primarily ancient stars that make up this cluster is F2 so its stars would be expected to present, much like our Sun, as yellow in colour. From close inspection of the above image, you will note that there are a number of blue stars present within the cluster. You are no doubt aware that only giant and short lived stars shine blue. So how can there be blue stars in a 11billion year old globular cluster? It is thought that mass transfer between older cooler stars, that get too close for comfort in the star dense cores of globular clusters, can rejuvenate and reinvent themselves as blue giants. These are referred to as 'blue stragglers'.

Messier3 may be seen roughly halfway between the bright alpha stars Arcturus and Cor Coroli." - Joel Cairo CEO of the Jodrell Plank Observatory.

Credit for map Roberto Mura, CC BY-SA 3.0 <https://creativecommons.org/licenses/by-sa/3.0>, via Wikimedia Commons

 

Messier 3

Globular star cluster Messier 3 in the constellation Canes Venatici. Composite image made from a number of exposures at different exposure times. 127mm. Apo refractor - Altair Astro 0.6x focal reducer and field flattener - Canon 600D DSLR at ISO1600.- Credit: Pip Stakkert.

Crop from widefield image showing enlargement of the Globular cluster - Credit: Pip Stakkert.

" This time of the year M3 is straight overhead at the Jodrell Plank Observatory. All the team like to view these beautiful and ancient balls of stars. The cluster is quite bright at apparent magnitude 6.2 and can be seen from a dark site with binoculars as a small misty patch of luminosity. It can be found  halfway along an imaginary line between the two bright stars Arcturus and Cor Caroli. The cluster is about 33,900 light years from our Solar System and is made up of approximately 500,000 stars. It is one of the youngest of the globular clusters with an estimated age of 8 billion years. The cluster contains a large number of variable stars and has an above average abundance of heavier elements. - Kurt Thrust acting CEO and current Director of the Jodrell Plank Observatory.

" We are happy to congratulate our Facilities Manager-May Fleming and our Instrumentation Engineer and Associate Astronomer' - Jolene McSquint  on the announcement of their intended wedding in July this year.  Everyone enjoys a 'summer wedding' and the Observatory staff are no exception".  – Karl Seguine - Community outreach coordinator.