Starship Asterisk*

NGC 2419: Intergalactic Wanderer

Explanation: Stars of the globular cluster NGC 2419 are packed into this Hubble Space Telescope field of view toward the mostly stealthy constellation Lynx. The two brighter spiky stars near the edge of the frame are within our own galaxy. NGC 2419 itself is remote though, some 300,000 light-years away. In comparison, the Milky Way's satellite galaxy, the Large Magellanic Cloud, is only about 160,000 light-years distant. Roughly similar to other large globular star clusters like Omega Centauri, NGC 2419 is intrinsically bright, but appears faint because it is so far away. Its extreme distance makes it difficult to study and compare its properties with other globular clusters that roam the halo of our Milky Way galaxy. Sometimes called "the Intergalactic Wanderer", NGC 2419 really does seem to have come from beyond the Milky Way. Measurements of the cluster's motion through space suggest it once belonged to the Sagittarius dwarf spheroidal galaxy, another small satellite galaxy being disrupted by repeated encounters with the much larger Milky Way.

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If this globular cluster, pictured, is considered 'mostly stealthy', I can't wait for you to show me a globular cluster that is considered a 'big showoff.'

De58te wrote: ↑Thu Apr 13, 2023 11:13 am If this globular cluster, pictured, is considered 'mostly stealthy', I can't wait for you to show me a globular cluster that is considered a 'big showoff.'

It's the Lynx constellation, not the globular cluster, that is "mostly stealthy". Although, I must admit, I don't know why that is, either.

Is it globular?
How come we see a ring in the place of a dense core?
...

You may notice blue stars scattered throughout this globular cluster. Since globulars are very old, the presence of blue stars needed an explanation, which astronomers figured out: some of the old stars sometimes collide in the densely populated central regions, resulting in a hotter, blue star. These are called "blue stragglers". NGC 2419 has more blue stragglers than most globulars and they are less centrally located, and astronomers consider this to be interesting regarding the evolution of this particular cluster. See, for example, https://iopscience.iop.org/article/10.1 ... .text.html .

Roger Venable wrote: ↑Thu Apr 13, 2023 1:00 pm You may notice blue stars scattered throughout this globular cluster. Since globulars are very old, the presence of blue stars needed an explanation, which astronomers figured out: some of the old stars sometimes collide in the densely populated central regions, resulting in a hotter, blue star. These are called "blue stragglers". NGC 2419 has more blue stragglers than most globulars and they are less centrally located, and astronomers consider this to be interesting regarding the evolution of this particular cluster. See, for example, https://iopscience.iop.org/article/10.1 ... .text.html .

And if you can't find the blue stragglers...


Ann

bystander wrote: ↑Thu Apr 13, 2023 11:20 am

De58te wrote: ↑Thu Apr 13, 2023 11:13 am If this globular cluster, pictured, is considered 'mostly stealthy', I can't wait for you to show me a globular cluster that is considered a 'big showoff.'

It's the Lynx constellation, not the globular cluster, that is "mostly stealthy". Although, I must admit, I don't know why that is, either.

From the Lynx link at Wikipedia:

Naming it Lynx because of its faintness, he challenged future stargazers to see it, declaring that only the lynx-eyed (those with good sight) would have been able to recognize it