|Right Ascension||17 : 40.7 (h:m)
|Declination||-53 : 40 (deg:m)
|Visual Brightness||5.9 (mag)
|Apparent Dimension||26.0 (arc min)|
Discovered by Lacaille in 1751-52.
This conspicuous globular is one of the two nearest to us (the other one is M4); currently it seems that M4 is a bit closer: M4 is at about 6,800 and NGC 6397 at 7,200 light years, but the uncertainty is large enough that the sequence may change..
NGC 6397 is one of the at least 20 globulars of our Milky Way Galaxy which have undergone a core collapse, i.e. its core has contracted to a very dense stellar agglomeration; this is the nearest such globular.
The image in this page was obtained by Till Credner and Sven Kohle. It is a magnification of a small region of a much larger (wider-field, 27x39 deg) photograph obtained within their Constellations Triangulum Australe, Norma, Ara photography, which was obtained by Sven Kohle on June 11, 1994, 02:23 LT from Cerro Tololo, Chile with a 50mm f/2.8 photo lens, exposed 30 min on Scotchchrome 400 film.
In John Caldwell's observing list. In the Astronomical League's Southern Sky Binocular Club list. Caldwell 86 in Patrick Moore's list.
The HST has investigated globular cluster NGC 6397 for faint red dwarf stars, in order to check the abundance of these "Dark Matter" candidates. Look at the first and second HST press release on this thread.
Last Modification: March 29, 1998