16 replies to this topic

[roelb]

For the October observing challenge I propose five "Arp-objects".

As per https://en.wikipedia...culiar_Galaxies

<The Atlas of Peculiar Galaxies is a catalog of peculiar galaxies produced by Halton Arp in 1966.

  A total of 338 galaxies are presented in the atlas, which was originally published in 1966 by the California Institute of Technology.

  The primary goal of the catalog was to present photographs of examples of the different kinds of peculiar structures found among galaxies.>

 

Interesting sites (from which also some info here was gathered):

http://www.richweb.f...arp_objects.htm

http://ned.ipac.calt...Arp/frames.html

https://cseligman.co...xt/arpatlas.htm

http://338arps.com/

 

For the southern hemisphere I propose: Arp 244 "Antennae Galaxies" - 245 - 252 - 292 - 321

 

All images with Evolution 8 @ f/5 - no filter

All with ZWO ASI290MM using SharpCap 3.2 except Arp 319 with Lodestar X2 Mono using Starlight Live

 

Arp 28 - NGC 7678 - PGC 71534 "Spiral Galaxy with one heavy arm"

Discovered (Sep 15, 1784) by William Herschel
A 12th-magnitude spiral galaxy (type SAB(rs)c?) in Pegasus
Physical Information: Based on a recessional velocity of 3490 km/sec, NGC 7678 is about 160 million light years away,

Given that and its apparent size of 2.15 by 1.65 arcmin, it is about 100 thousand light years

 

8 x 10 s

 

 

Arp 113 - NGC 70 - Elliptical Galaxy close to and perturbing Spiral Galaxy"

Galaxy Group: NGC 67+68+69+70+71+72+74 + PGC 1891312+1889183+1889390+1887599+138159 in Andromeda

Physical Information NGC 68: Based on a recessional velocity of 5735 km/sec (and H0 = 70 km/sec/Mpc), NGC 68 is about 265 to 270 million light years away.

Given that and its apparent size of about 1.35 by 1.2 arcmin, it is about 105 thousand light years across.

 

12 x 10 s

 

 

Arp 170 - NGC 7578A+B - Hickson 94E - "Galaxy with diffuse counter-tail"

NGC 7578A is a spiral galaxy (0.7 x 0.6 arcmin) and NGC 7578B is a elliptical galaxy (1.7 x 1.2 arcmin)

Arp 170 is located in the Great Square of Pegasus at a distance of about 525 million light years.

Arp classed it under galaxies with diffuse counter-tails. It is part of the Hickson 94 which is part of the Abell 2572A a subgroup of Abell 2572.

Only the two brightest are part of Arp 170.

 

7 x 15 s

 

 

Arp 249 - PGC 200388 + PCG 1679585 - "Galaxy with appearance of fission"

Interacting galaxy pair in Pegasus

In surrounding area: PGC 24 - Elliptical galaxy

 

10 x 10 s

 

 

Arp 319 - NGC 7317+18A&B + 19 + 20 - "Stephan's Quintet" - "Group of galaxies"

Stephan's Quintet is a visual grouping of five galaxies of which four form the first compact galaxy group ever discovered.

The group, visible in the constellation Pegasus, was discovered by Édouard Stephan in 1877 at the Marseille Observatory.

The group is the most studied of all the compact galaxy groups.

The brightest member of the visual grouping is NGC 7320 that is shown to have extensive H II regions, identified as red blobs, where active star formation is occurring.

Four of the five galaxies in Stephan's Quintet form a physical association, Hickson Compact Group 92, and will likely merge with each other.

Two space telescopes have recently provided new insight into the nature of the filament, which is now believed to be a giant intergalactic shock-wave

(similar to a sonic boom but traveling in intergalactic gas rather than air) caused by one galaxy (NGC 7318B) falling into the center of the group

at several millions of kilometers per hour.

 

11 x 30 s

[alphatripleplus]

Very nice selection, Roel.

[flyingcougar]

Thanks Roel for starting the October challenge!

 

I'll go ahead and pin it now so it stays on top.

[selfo]

Thanks Roel

 

Looking forward to this October challenge.  Now if the clouds would clear up before the moon gets too bright... 

 

Stewart

[allenirvan]

I spent most of the night re-acquainting myself with my CEM25 and sharpcap after taking a year off.  I did manage to get the capture below of Stephan's Quintet and a rather unimpressive shot at ARP170.  Great list of objects Roel; I'm looking forward to working on the others.  Both of these were taken from a red zone with a ASI290MM on a SW80ED @ F7.5 with an Orion LP filter, 15s frames for a total of 40 minutes on each.

 

Stephan's Quintet

 

ARP170

 

Allen

[Barkingsteve]

Had a go last night while capturing some other stuff.

sharpcap pro, 294mc pro @-5c with idas p2 filter, 130 pds on evo mount

all 15 second captures at 150 gain saved as viewed, cropped and saved as jpeg

From Bortle 8-9 skies.

 

ARP 28 29 frames stacked

 

ARP 113 29 frames stacked

 

ARP 170  29 frames stacked

 

ARP 319  29 frames stacked

 

missed one but not a bad haul 

Edited by Barkingsteve, 03 October 2019 - 03:40 AM.

[saguaro]

A fun challenge! Here are my efforts with my 14Edge on 1600GTO mount, using Starizona Night Owl F/4 reducer (prototype), ZWO 1600 color cooled camera, UV/IR filter, and SharpCap live stacking with master flat and master dark. All are 30sec subs at Gain 350, saved as viewed, cropped, and converted to JPG.

 

NGC 7678 (Arp 28), 16x30sec

 

 

Arp 249, 18x30sec

 

[saguaro]

NGC 70 (Arp 113) 10x30sec

 

[saguaro]

NGC 70 (Arp 113) 10x30sec annotated

 

[saguaro]

NGC 7578A+B (Arp 170), 11x30sec

 

[saguaro]

Stephan's Quintet, 21x30sec

 

 

annotated:

 

[selfo]

Some dim objects for this challenge but using Binning 2 on my camera I was able to bring out sufficient  detail for Arp 28 and Stephan's Quintet in my Bortle 7 backyard. 

 

https://astrob.in/b8ptfx/0/    Arp 28 

 

https://astrob.in/die3d9/0/    Arp 113

 

https://astrob.in/qe9hhy/0/    Arp 319  Stephan’s Quintet

 

https://astrob.in/8y65fa/0/   Arp 249

 

https://astrob.in/0lrv8i/0/     Arp 170

 

BTW.  Signed up with Astrobin for storage and posting of images.  A very nice utility for cataloging your Images.   It even plate solves your Pics.    Free for up to 10 pics.  Unlimited  pics is about 35 bucks a year

 

Cheers

 

Stewart

Edited by selfo, 04 October 2019 - 12:30 PM.

[Rickster]

Excellent selections Roel.  I like it when the selections allow shooting near zenith.  And they gave me an excuse to test my new ASI183MM Pro on the target type that I bought it for (distant galaxies).

 

All were taken with the following set up:  SkyWatcher 16" Newt (1800mm fl) on a 1960s GEM updated with ONSTEP controller and operated remotely from a warm room with CdC.  Camera was an ASI183 mono cooled with a cheap UV/IR cut filter.  No coma corrector.  No darks or flats.  These shots were taken on 10/5 through 10/7 during a partial moon and average seeing conditions.  These are faint targets so I let the stacks run for roughly 10 minutes instead of my usual 5 min.  Bin 3x3.  Exposures were processed on the fly with Sharpcap, saved as viewed and resized (or  cropped) to meet the forum 500kb limit.

 

ARP 28  10x54sec

Attached Thumbnails

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Edited by Rickster, 08 October 2019 - 11:19 PM.

[Rickster]

ARP 113 10s x 60

 

 

Attached Thumbnails

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[Rickster]

ARP 170  10s x 61

Attached Thumbnails

• 

[cmooney91]

Wow Rick! Incredible detail and speed you are getting with that 16".  Envious.

 

Over the weekend I got to try out my new Bresser 208mm F3.9 Imaging Newtonian with my RisingCam IMX290 mono and SharpCap3.2.  The image scale was a little silly at 0.74"/px  but I'm planning to focal reduce it back to ~1" and gain some speed.

 

Arp319 Stephans Quintet  3100 Gain 8s x 75 = 600s (Cropped and Compressed)

 

I shot more of the challenge objects, but the stretch did not save so I might try them again.

Edited by cmooney91, 21 October 2019 - 08:39 AM.

[alphatripleplus]

Great captures from everyone. I just missed getting at least one of the October targets by the end of the month, but I have been playing with my C6 from my new location. Here is a very quick look (180 sec) from last night at Stephan's Quintet with my C6 and Lodestar X2 mono at f/4.0 using twin stacked f/6.3 reducers, no filters, (dust bunny included), no darks, and captured with Starlight Live 3.3:

 

Arp319 (Stephan's Quintet); 6 x 30 sec

 

 

 

Here is a cropped view of the centre of the frame - greater resolution and longer than 3 minute total exposure would have helped to see more detail: