Jump to content

  •  

* * * * *

Cosmic Challenge: Abell Galaxy Cluster (AGC) 1060


Discuss this article in our forums

Cosmic Challenge: Abell Galaxy Cluster (AGC) 1060

 

April 2021

 

 

Phil Harrington

 

This month's suggested
aperture range
:

Large scopes:
10-inch (25cm)
to 14-inch (36cm)

 

Target

Type

RA

DEC

Const

Mag

Size

Abell Galaxy Cluster 1060

Galaxy
cluster

10h 36.9m

-27° 31.0

Hydra

--

168'

 

Entry number 1060 in the Abell Catalog of Galaxy Clusters (AGC), also known as Hydra 1, covers nearly 3° of our southern spring sky and includes more than 100 individual galaxies.  Fourteen of those have assignments in the New General Catalog, while another belongs to the NGC's supplemental Index Catalog.  Six of those NGC galaxies shine brighter than 14th magnitude and lie within a 20' field.   The dozens of other cluster members are all too faint to have been included in those catalogs, but instead have individual entries in the European Southern Observatory Galaxy Catalog (ESO), Millennium Galaxy Catalog (MGC), and Principal Galaxies Catalog (PGC).

Above: Evening star map. Credit: Map adapted from Star Watch by Phil Harrington.


Above: Finder chart for this month's Cosmic Challenge

Credit: Chart adapted from Cosmic Challenge: The Ultimate Observing List for Amateurs by Phil Harrington.
Click on the chart to open a printable PDF version.

 

Finding AGC 1060 is a simple task as long as you can spot 4.5-magnitude SAO 179041.  This red giant sun overlaps the center of the cluster and lies 4¼° north of Alpha (α) Antliae.  Of course, finding Alpha Antliae presents its own challenge, since it shines at only magnitude 4.2 and lies far from any handy reference stars.  My best suggestion is use binoculars and start off from the trapezoidal body of Corvus the Crow.  Extending a diagonal line southwestward from Algorab [Delta (δ) Corvi] through Epsilon (ε) Corvi and continuing for another 24°, you will come to Alpha Antliae and, a degree to its northeast, Delta (δ) Antliae.  SAO 179041 is now about two-thirds of a finder field to their north.  Center SAO 179041 in your telescope field, switch to about 100x, and take a moment to orient yourself.  In particular, note the 7th-magnitude sun, SAO 179027, 16' to its south-southwest.

 

An arc of no fewer than six NGC galaxies curves south and west from SAO 179041.  How many can you see?  The brightest pair is formed by NGC 3309 and NGC 3311.  Both lie just west of the midpoint between those two SAO reference stars.  My 10-inch scope shows NGC 3309 as a small, circular disk with a concentrated core at its heart.  Even though its integrated magnitude is greater, NGC 3311's lower surface brightness makes it less apparent than NGC 3309.  It too appears circular, but evenly illuminated.

 

 

 

Above: A portion of AGC 1060 as portrayed through the author's 10-inch (25cm) telescope.

 

 

Another dim galactic ember glows to the east of the halfway point between the two SAO stars and just west of a pair of 12th-magnitude points.  NGC 3312 appears quite elongated, oriented almost exactly north-south, and is highlighted by a bright stellar nucleus.   Photos of the cluster reveal this to be a classic spiral galaxy tilted partially to our perspective.  Monster backyard scopes may also hint at the dark lane that runs along the edge of the spiral arm halo.

 

NGC 3316 is nestled 8' due east of NGC 3312.  This little barred spiral is one of the toughest of the NGC galaxies in AGC 1060, since its tiny disk appears no more than 1' across visually and shines at only 13th magnitude.

 

Veering off the arc for a moment, try your luck with an even dimmer pair, NGC 3314A and 3314B.  Neither breaks the 13th-magnitude barrier, with the latter only managing a weak 14th-magnitude effort.  A 14th-magnitude star is superimposed on the northern tip of NGC 3314A, while an even dimmer field star abuts NGC 3314B to the east.

 

Okay, back to SAO 179041.  Scan 11' due west for the faint patch of NGC 3308.  A good eye will show that its dim disk is slightly oval, oriented south-southwest/north-northeast, and draws to a brighter central nucleus.

Now, look 20' northwest of SAO 179041 for the faint glow of NGC 3305, just tucked inside the edge of the cluster.  Its small, round disk lies just to the east of a 12th-magnitude star.  The 10-inch offers no hint of a centralized core, but rather, shows only a dim, evenly illuminated blur.

 

NGC 3315 is found some 14' north of SAO 179041 and just east of an 11th-magnitude sun.  At 106x, my 10-inch reveals a small, faint glow elongated northwest-southeast.  Averted vision will likely be needed to see this little 14th-magnitude S0 system.

 

A tight group of four faint galaxies, cross-listed in Paul Hickson's Galaxy Group catalog as Hickson 48, is found another 9' further northeast still.  Brightest of that bunch is IC 2597, a small, 13th-magnitude blur set just east of a faint star.  Gathered round it are galaxies PGC 31588 (magnitude 14.8), PGC 31577 (magnitude 16.3), and PGC 31580 (magnitude 16.7).  At those magnitudes, I'm afraid that we will have to leave that trio to the big guns in the next chapter.

 

Three NGC members guard the western flank of AGC 1060.  To find them, move ¾° due west to 7th-magnitude SAO 178978.  NGC 3285 lies just 7' to the star's southwest and reveals a small, oval glow tilted west-northwest to east-southeast.   A faint stellar core is centered within.  The other two NGC galaxies here, NGC 3285A, 12' to the west-southwest of NGC 3285, and NGC 3285B, 18' to its southeast, are each a paltry 14th magnitude.

 

Finally, the barred spiral NGC 3336 lies near the eastern edge of the cluster, about ¾° east-southeast of center.  This is a tough catch.  Look for a dim, slightly elongated smudge of uniform grayish light.


Completing this challenge will give you 14 more notches in your galaxy belt, but there are still many fainter galaxies lying in wait.  The table below includes the central region of AGC 1060, listing galaxies shining at magnitude 14.5 or brighter, while the finder chart here plots them amongst stars to magnitude 15.  See how many of these other galactic denizens you can find.

 

 

Central Region of AGC 1060

(highlighted galaxies are discussed above)

Target

ESO

RA

DEC

Magnitude

Size

NGC 3285A

 

10 32.8

-27 31.4

14.5p

1.1x0.9'

PGC 31212

501-13

10 33.5

-26 53.8

13.9p

1.3x0.5'

NGC 3285

 

10 33.6

-27 27.3

13.1b

2.5x1.4'

NGC 3285B

 

10 34.6

-27 39.1

13.9p

1.5x1.1'

PGC 31312

501-20

10 34.8

-27 12.8

14.5b

0.9x0.6'

PGC 31310

436-44

10 34.8

-28 29.8

13.9p

1.1x0.7'

PGC 31316

436-46

10 34.8

-28 35.0

13.4p

2.7x2.0'

PGC 31360

437-4

10 35.4

-28 18.9

13.9p

1.8x1.1'

PGC 31366

501-25

10 35.4

-26 39.8

14.1p

1.7x0.8'

NGC 3305

 

10 36.2

-27 09.7

13.8b

1.1'

NGC 3307

 

10 36.3

-27 31.8

14.5v

0.8x0.4'

PGC 31443

501-35

10 36.4

-27 00.0

14.2p

1.5x0.5'

NGC 3308

 

10 36.4

-27 26.3

12.9b

1.7x1.2'

NGC 3309

 

10 36.6

-27 31.1

12.6b

1.8x1.5'

NGC 3311

 

10 36.7

-27 31.6

11.6v

2.1x1.9'

PGC 31488

437-11

10 36.8

-27 55.2

14.3b

1.1x0.5'

PGC 31504

437-15

10 37.0

-28 10.7

13.5p

2.4x0.4'

NGC 3312

 

10 37.0

-27 33.8

12.7p

3.3x1.2'

NGC 3314B

 

10 37.2

-27 39.5

13.5

0.3x0.2'

NGC 3314A

 

10 37.2

-27 41.0

14

1.6x0.7'

NGC 3315

 

10 37.3

-27 11.5

14.4b

1.1x0.9'

NGC 3316

 

10 37.6

-27 35.6

13.6p

1.2x1.0'

PGC 31577

 

10 37.7

-27 03.5

16.4b

0.6'x0.3'

PGC 31580

 

10 37.7

-27 02.6

17.0

0.3'

IC 2597

 

10 37.8

-27 04.9

12.8b

2.5x1.7'

PGC 31588

 

10 37.8

-27 07.3

15.0b

0.9'x0.7'

PGC 31585

501-56

10 37.8

-26 37.8

13.8p

2.0x0.4'

PGC 31638

501-65

10 38.6

-27 44.3

13.7p

1.7x1.0'

PGC 31683

501-68

10 39.3

-26 50.4

14.3p

2.0x0.6'

NGC 3336

 

10 40.3

-27 46.6

13.0p

1.9x1.5'

 

Good luck with this month's challenge! And be sure to post your results in this column's discussion forum.

 

Remember that half of the fun is the thrill of the chase.  Game on!



About the Author:

Phil Harrington writes the monthly Binocular Universe column in Astronomy magazine and is the author of 9 books on astronomy, including Cosmic Challenge: The Ultimate Observing List for Amateurs.  Visit www.philharrington.net to learn more.

Phil Harrington's Cosmic Challenge is copyright 2021 by Philip S. Harrington.  All rights reserved.  No reproduction, in whole or in part, beyond single copies for use by an individual, is permitted without written permission of the copyright holder.

 


  • okiestarman56, John O'Hara and Knasal like this


4 Comments

Phil:

 

Thanks for another cosmic challenge.  It looks to be clear tonight, so I'll be taking a look.

 

I'm looking at Sky Safari and mapping out a star hop to SAO 179041. I'm thinking Mu Hydrae to the SAO 155980, mag 6.1, about 3 degrees. 

 

Mu Hydrae is the guide star I use for the Ghost of Jupiter  and it's right in the middle so I'll stop off for a visit.

 

Then to 44 Hydrae, mag 5.1 about 4.7 degrees.

 

And then to SAO 179041, about 3.7 degrees.

 

My 10 x 50 mm finder has a 6.4 degree field so these should be doable. 

 

I'm looking forward to some fun. 

 

Jon

    • Dave Mitsky, PhilH, Knasal and 1 other like this

A quick update:

 

I've spent an hour or two each of these last two nights viewing the region around SOA 179041 with the 22 inch, lots of stuff to see and identify.  The star hop did work out.

 

It's pretty low in the sky even from my southerly location with its open southern view so keep that in mind.

 

Jon

    • PhilH and Voyager 3 like this
Photo
TelescopeBah
Apr 05 2021 06:59 PM
Hey Jon! Wish I could have been there with your 22"! But I did have some fun myself last night! I was able to find the spot without any trouble, and was able to make out at the least four of the galaxys for sure, but I think I may have seen six or seven, in my 12". It was really fun picking them out! The cluster transits at about 40° here. LORD willing I'm going to be observing them again tonight to see if I can pick out any More. Thanks again Phil for the fun challenge!!
Photo
TelescopeBah
Apr 06 2021 07:46 AM
Well I had a great observing session last night! I was able to identify 11 of the galaxys. Here is a list of what I was able to see with a 12"
NGC3307mag.14.5 (averted vision)
NGC3308mag.12.9
NGC3309mag.12.6
NGC3311mag.11.6
NGC3312mag.12.7
NGC3314Amag.14
NGC3314Bmag.13.5 (averted vision)
NGC3315mag.14.4
NGC3316mag.13.6
IC2597mag12.8
PGC31588mag15


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics