Документ взят из кэша поисковой машины. Адрес оригинального документа : http://zebu.uoregon.edu/messier/m90.txt Дата изменения: Sat Apr 23 03:12:27 1994 Дата индексирования: Mon Oct 1 21:34:42 2012 Кодировка: Поисковые слова: rigel

M90 will be a dissappointing target for amateurs as its overall
surface brightness is somewhat low. There is strong spiral
structure as outlined by the clearly visible dust lanes in this
blue exposure. M90 has an active nucleus. It is noteworthy in
that M90 has a blueshift with respect to the Milky Way, even
though it is located at a distance of 40 Million light years from
us. This is because M90 is a member of the Virgo Cluster and its
random velocity due to the gravitational potential well of Virgo
is larger than its relative expansion velocity with respect to
the Milky Way. That random component is accidentally pointed in
our direction such that M90 has a velocity of about -250 km/s.