With the persistence of bad weather, I am scrapping the bottom of my drawer looking for old images not yet processed. This one is long overdue, and is related to a very interesting object,
NGC2419 (Caldwell 25), one of the farthest Globular Clusters of Milky way.
Laying at 300000 light years (!) (see picture below) from our galaxy's center (nearly the double of Large Magellanic Cloud), it was thought to be gravitationally disconnected by the Milky way. Recent observations indicate that NGC 2419 is still bound to our galaxy, just moving in a highly eccentric orbit, and taking 3 billion years (1) to complete it.
Intrinsically it is one of the brightest and most massive globular clusters of our galaxy.
It was proposed that NGC 2419 could be, as Omega Centauri, the remnant of a dwarf spheroidal galaxy disrupted and accreted by the Milky Way. However, later research seems to have disproved this theory.
It was found to be composed of two different star populations, one way more helium-rich than the other, which does not fit the current model for globular cluster formation (which leads to a very homogeneous population). This raises new questions on how this globular cluster was formed.
It was discovered by William Herschel on December 31, 1788.
Picture: 3D rendering of NGC 2419 position in relation to Milky Way and Sun, to better illustrate the huge distance of this globular cluster. Its galactic coordinates are (180°, 25°), it is therefore placed exactly on the sun - galaxy center vertical plane at 25 degrees height on the galactic plane. Milky Way original image by Robert Hurt, edited by galaxymap.org.
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