APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Comments and questions about the APOD on the main view screen.
User avatar
APOD Robot
Otto Posterman
Posts: 4783
Joined: Fri Dec 04, 2009 3:27 am

APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Post by APOD Robot » Sun Aug 09, 2015 4:11 am

Image HCG 87: A Small Group of Galaxies

Explanation: Sometimes galaxies form groups. For example, our own Milky Way Galaxy is part of the Local Group of Galaxies. Small, compact groups, like Hickson Compact Group 87 (HCG 87) shown above, are interesting partly because they slowly self-destruct. Indeed, the galaxies of HCG 87 are gravitationally stretching each other during their 100-million year orbits around a common center. The pulling creates colliding gas that causes bright bursts of star formation and feeds matter into their active galaxy centers. HCG 87 is composed of a large edge-on spiral galaxy visible near the image center, an elliptical galaxy visible to its right, and a spiral galaxy visible near the top. The small spiral near the center might be far in the distance. Several stars from our Galaxy are also visible in the foreground. Studying groups like HCG 87 allows insight into how all galaxies form and evolve.

<< Previous APOD This Day in APOD Next APOD >>
[/b]

User avatar
Ann
4725 Å
Posts: 12255
Joined: Sat May 29, 2010 5:33 am

Re: APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Post by Ann » Sun Aug 09, 2015 4:50 am

Today is repeat day at APOD, and today's picture is from 2003. In my opinion, the most interesting thing about it is this link, which not only provides a comparison between the Gemini telescope image of HCG 87 and the HST image of the same group, but also explains why we should bother with ground-based telescope images of deep space objects at all:
"Historically, the main advantage of large ground-based telescopes, like Gemini, is their ability to collect significantly more light for spectroscopy than is possible with a telescope in space," said Phil Puxley, Associate Director of the Gemini South Telescope. He explains, "The Hubble Space Telescope is able to do things that are impossible from the ground. However, ground-based telescopes like Gemini, when conditions are right, approach the quality of optical images now only possible from space. One key area - spectroscopy of faint objects, which requires large apertures and fine image quality - is where large telescopes like Gemini provide a powerful, complementary capability to space-based telescopes."
Ann
Color Commentator

hoohaw

Re: APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Post by hoohaw » Sun Aug 09, 2015 9:45 am

The discussion, under "Curiosity's View," is still a repeat of the previous day's APOD (Full Earth, Full Moon) discussion. Is it only my computer somehow? I had wanted to comment on Curiosity's View, and never got the chance!

hoohaw

Re: APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Post by hoohaw » Sun Aug 09, 2015 9:48 am

Think of going to the fair, and going on Bumper Cars! That's what our Universe is, bumper cars for Galaxies! (Better than Clown Cars, I suppose!)

hoohaw

Re: APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Post by hoohaw » Sun Aug 09, 2015 1:52 pm

...though, now that I think of it, those black holes, with impossible jets coming out of them, are pretty analogous to clown cars, aren't they!

User avatar
Chris Peterson
Abominable Snowman
Posts: 16924
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Post by Chris Peterson » Sun Aug 09, 2015 2:35 pm

hoohaw wrote:The discussion, under "Curiosity's View," is still a repeat of the previous day's APOD (Full Earth, Full Moon) discussion. Is it only my computer somehow? I had wanted to comment on Curiosity's View, and never got the chance!
It's only your computer, apparently. Maybe a caching issue. Each of the last two days' APODs have their own, separate discussions.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Meekmoe

Re: APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Post by Meekmoe » Sun Aug 09, 2015 2:50 pm

hoohaw wrote:The discussion, under "Curiosity's View," is still a repeat of the previous day's APOD (Full Earth, Full Moon) discussion. Is it only my computer somehow? I had wanted to comment on Curiosity's View, and never got the chance!
I get the same, full earth full moon discussion under the curiosity view...

User avatar
Chris Peterson
Abominable Snowman
Posts: 16924
Joined: Wed Jan 31, 2007 11:13 pm
Location: Guffey, Colorado, USA

Re: APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Post by Chris Peterson » Sun Aug 09, 2015 2:58 pm

Meekmoe wrote:
hoohaw wrote:The discussion, under "Curiosity's View," is still a repeat of the previous day's APOD (Full Earth, Full Moon) discussion. Is it only my computer somehow? I had wanted to comment on Curiosity's View, and never got the chance!
I get the same, full earth full moon discussion under the curiosity view...
You get this when you go directly to that discussion heading under "The Bridge: Discuss an Astronomy Picture of the Day", or when you click on the "Discuss" link at the bottom of the "Curiosity's View" APOD? Because the link in the latter is pointing to the wrong place. But the discussion is still here if you simply go to it directly from the Asterisk forums, and not from APOD.
Chris

*****************************************
Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

User avatar
Coil_Smoke
Ensign
Posts: 83
Joined: Sun Nov 17, 2013 7:57 am

Re: APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Post by Coil_Smoke » Sun Aug 09, 2015 6:03 pm

At first glance :shock: the small spiral galaxy in the center looked like a human hand.(Sorta pointing to 8 O"Clock position) Must be those old 'Star Trek' episodes like "Who Morns For Adonis' with the huge outstretched hand in space.

Boomer12k
:---[===] *
Posts: 2691
Joined: Sun Apr 22, 2007 12:07 am

Re: APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Post by Boomer12k » Sun Aug 09, 2015 6:31 pm

Why does the edge on Galaxy have an "X" looking pattern???

Nice Pic.

:---[===] *

Boomer12k
:---[===] *
Posts: 2691
Joined: Sun Apr 22, 2007 12:07 am

Re: APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Post by Boomer12k » Sun Aug 09, 2015 6:39 pm

Went to the telescope website for Gemini.....watched the video....I WANT ONE.... :D

:---[===] *

User avatar
neufer
Vacationer at Tralfamadore
Posts: 18805
Joined: Mon Jan 21, 2008 1:57 pm
Location: Alexandria, Virginia

Re: APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Post by neufer » Sun Aug 09, 2015 6:39 pm

Boomer12k wrote:
Why does the edge on Galaxy have an "X" looking pattern???
It is gravitationally warped by the elliptical galaxy.
Art Neuendorffer

User avatar
LocalColor
Science Officer
Posts: 266
Joined: Sat Mar 31, 2012 9:11 pm
Location: Central Idaho, USA

Re: APOD: HCG 87: A Small Group of Galaxies (2015 Aug 09)

Post by LocalColor » Sun Aug 09, 2015 8:29 pm

Boomer12k wrote:Why does the edge on Galaxy have an "X" looking pattern???

Nice Pic.

:---[===] *
Thanks for pointing that out, I miseed it. :oops:

Lovely photo and very educational.