Re: M90 (Arp 76) and M89

Brian Ottum

Fascinating about the red vs. blue shift. I had thought everything was various levels of red shift.

-----Original Message-----
From: <> On Behalf Of Gregg Ruppel
Sent: Thursday, March 18, 2021 12:36 PM
To: undisclosed-recipients:
Subject: [DarkSkyNewMexico] M90 (Arp 76) and M89

Hi all

M90 and M89 are two large galaxies in Virgo. M90, along with IC3583, make up Arp 76, a "spiral with small high surface brightness companion on arm". Although these two are only about 100,000 LY apart, it is unclear whether they are truly interacting. M90 is blue-shifted, approaching us while IC3583 is red-shifted, moving away. M89 is a large, spherical elliptical that sports outer envelopes of dust and gas and a long tidal tail, suggesting some past interaction. An estimated
2000 globulars surround M89.

M90 (Arp 76), 1.3X crop:

M89, 1.3X crop:

Annotated version:

LRGB, 10 hours total exposure from Dark Sky New Mexico

Clear skies,

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