Globular star cluster Messier 4, is drawn by the Grok AI
Messier 4 (M4 or NGC 6121) is a globular star cluster located in the constellation Scorpius. Here's some key information about it:
- Location: M4 is one of the easiest globular clusters to locate due to its proximity to the bright star Antares, the heart of Scorpius. It's about 1.3 degrees to the west of Antares.
- Distance: It is approximately 7,200 light-years away from Earth, making it one of the closest globular clusters to our solar system.
- Age: This cluster is quite old, with estimates suggesting it's around 12.2 billion years old, which is nearly as old as the universe itself.
- Size: M4 has a diameter of about 75 light-years, but visually it spans around 26 arc minutes (which is roughly the size of the Moon when viewed from Earth).
- Number of Stars: It contains hundreds of thousands of stars, with estimates up to about 500,000 stars. The cluster is densely packed at its core.
- Special Features:
- Millisecond Pulsars: M4 is notable for hosting several millisecond pulsars, which are neutron stars that spin hundreds of times per second. These pulsars are thought to have been spun up by accreting mass from a companion star.
- Planetary Nebula: M4 contains a planetary nebula, known as NGC 6121-1 or M4 PN, which is quite rare for a globular cluster because planetary nebulae are usually associated with the later stages of stars in a galaxy's disk, not in globular clusters.
- White Dwarfs: Observations have also identified many white dwarfs within M4, which are the remnants of stars similar to our Sun after they have exhausted their nuclear fuel.
- Observation: M4 is visible with binoculars as a faint, fuzzy patch, but with a small telescope, you can resolve some individual stars at its edges. Larger telescopes reveal more detail, showing a rich field of stars.
- Scientific Importance: Due to its proximity and the variety of phenomena it contains, M4 is a popular target for both amateur astronomers and professional researchers studying stellar evolution, dynamics within globular clusters, and the behavior of star systems in dense environments.
This cluster's proximity and the diversity of its stellar content make it an excellent subject for studying the processes that govern star life cycles, from formation through to the end stages of stellar evolution.
A few important clarifications to what the Artificial Intelligence said:
According to modern and more plausible estimates, the Messier 4 star cluster is indeed the closest globular cluster to the Solar System, and the distance to it is now considered to be close to 6,000 light years (and possibly less than 6,000 light years). There are a couple of competing clusters that could be a little closer. But one of them (the recently discovered, rather faint cluster FSR 1767 - also in the constellation Scorpius) is not a globular cluster in the classical sense, but only has similarities with globular clusters. The other (NGC 6397 in the constellation Ara) turned out to be significantly further away - almost 8 thousand light years.
I was unable to find confirmation of the existence of a planetary nebula within (inside) the Messier 4 cluster. Although, this would be an interesting feature, but so far it looks more like an error in the analysis of information by Artificial Intelligence.
Also, the question of the location of the planet "Methuselah" (the most ancient of the currently known exoplanets) within this globular cluster is not finally determined, because estimates of the distance to this planet show a value twice the distance to the cluster (namely, more than 12 thousand light years). And only the most optimistic assumptions allow that the planet and the pulsar around which it revolves are located on the outskirts of the cluster farthest from us (on the other side from us). But this is unlikely.
But there is another interesting discovery made relatively recently with the help of the Hubble Space Telescope. Analysis of the motion of the stars of the Messier 4 cluster shows the existence of a hidden mass in the center of the cluster in the amount of about 800 solar masses, which most likely indicates the presence of an intermediate-mass black hole in the center of the cluster. And if this is confirmed, then most likely this will be the first case of detection of this class of black holes.
In the process of studying the motion of individual stars in the M4 cluster, astronomers also studied the orbit of the cluster itself. It turned out that it is very elongated. Now the cluster is moving away from us at a high speed (about 70 km/sec) and is flying towards the galactic core, with which it periodically comes very close - every 100 million years. Passing by the galactic core, the globular star cluster Messier 4 experiences a strong tidal effect and loses stars. And since there have been quite a few such approaches during the life of the cluster, we can conclude that this cluster used to be much more massive and multi-star. But now only a memory of its former greatness remains.
Globular star cluster Messier 4 by 2.2-metre telescope at ESO’s La Silla Observatory
