Пн, 05.12.2016, 03:26:40
Приветствую Вас Гость
Последние сообщения · Участники · Правила форума · Поиск · RSS
Страница 1 из 11
Форум » Досуг » Космос » NGC 28
NGC 28
ingvarr
(65535) Вне сайта
Дата: 11.09.2016, 12:07:44 | Сообщение № 1
admin
Репутация: 729
Награды: 116
За 200 Сообщений За хорошую репутации


NGC 28 (другие обозначения — AM 0007-571, PGC 730) — эллиптическая галактика (E1) в созвездии Феникс.

Этот объект входит в число перечисленных в оригинальной редакции «Нового общего каталога».

Галактика была открыта английским астрономом Джоном Гершелем 28 октября 1834.

Звездная величина: 15,4
Созвездие: Феникс
Видимая Звездная Величина: 15,4
Ответить
ingvarr
(65535) Вне сайта
Дата: 11.09.2016, 12:08:22 | Сообщение № 2
admin
Репутация: 729
Награды: 116
За 200 Сообщений За хорошую репутации
Ответить
ingvarr
(65535) Вне сайта
Дата: 11.09.2016, 15:08:54 | Сообщение № 3
admin
Репутация: 729
Награды: 116
За 200 Сообщений За хорошую репутации
NGC 28 (= PGC 730 = PGC 395160)
Discovered (Oct 28, 1834) by John Herschel
A magnitude 13.8 elliptical galaxy (type E0?) in Phoenix (RA 00 10 25.2, Dec -56 59 21)
Historical Identification: Per Dreyer, NGC 28 (= GC 13 = JH 2310, 1860 RA 00 03 25, NPD 147 46.4) is "extremely faint, the preceding (western) of 2", the other being NGC 31. The position precesses to RA 00 10 26.5, Dec -56 59 38, which is 0.4 arcmin southeast of the center of the galaxy listed above and within its outer glow, and it does precede NGC 31 (which lies just to its east), so the identification is certain. However, as noted by Corwin, at one time some catalogs misidentified NGC 28 as NGC 31, and vice-versa; so the reader may still see their PGC designations reversed in some places.
Physical Information: Based on a recessional velocity of 9595 km/sec, a straightforward calculation indicates that NGC 28 is about 445 million light years away. However, for objects at such distances we should take into account the expansion of the Universe during the time it took their light to reach us. Doing that shows that the galaxy was about 430 million light years away at the time the light by which we see it was emitted, a little over 435 million years ago (the difference between the two numbers being due to the expansion of the intervening space during the light-travel time). Given that and its apparent size of 0.9 by 0.9 arcmin, it is about 115 thousand light years across. Unlike nearby NGC 25, which is listed as a member of Abell 2371, NGC 28 is not listed as such, and could be slightly behind the cluster. But the difference in its recessional velocity is well within the range of peculiar (non-Hubble-expansion) velocities for such clusters, so odds are that it is also a member of the cluster. Regardless of its association with the cluster (or not), it and NGC 31's essentially identical recessional velocities suggest that they may be physical companions.
Ответить
Форум » Досуг » Космос » NGC 28
Страница 1 из 11
Поиск:



             Рейтинг@Mail.ru     HotLog