Obs Report - Fornax Cluster, galaxies 10/1/10

[pgc hunter]

Had a rare clear night on Sunday Jan 10, and with the moon not rising until 2:30am I took the chance to hunt some galaxies.
Spent an hour and a half in the Fornax cluster observing each GX individually, then moved on to a few nice groups. Scope used was the 12" dob with Vixen LVW eyepieces.

Seeing was pretty atrocious, transparency was alright.

Scope: 12" F/4.6 dob
Time: 10:30pm - 2:30am
Seeing: 3/10
Transparency: 4/5

FORNAX CLUSTER

NGC 1399
Fornax, Size= 3.2x3.1', Mag V= 9.6, SB= 12.0

Largest and brightest of group. Round, nearly stellar core at 283x, faint 13th mag star at NE edge just O.3' from core.

NGC 1404
Fornax, Size= 2.5x2.3', Mag V= 10.0, SB= 11.7

Second brightest member of group. At 283, a stellaring was seen in the core, galaxy slightly elongated N-S, with a mag 12 star at SE edge.

NGC 1387
Fornax, Size= 2.4x2.2', Mag V= 10.7, SB= 13.3

283x - small, round with a condensed core.

NGC 1379
Fornax, Size= 2.0x1.9', Mag V= 10.9, SB= 12.3

283x - round, nearly stellar core, smaller and more diffuse than NGC 1387.

NGC 1381
Fornax, Size= 2.9x0.8', Mag V= 11.5, SB= 12.3

A nice spindle at 283x, oriented NW-SE. Stellar core.

NGC 1374
Fornax, Size= 1.8x1.8', Mag V= 11.1, SB= 12.2

283x - Small, Round with a stellar core. Forms part of trio with 1375 and 1373.

NGC 1374
Fornax, Size= 1.9x0.6', Mag V= 12.4, SB= 12.1

Smaller and fainter than 1374, slightly elongated E-W with a stellaring in the core intermittently visible at 283x.

NGC 1373
Fornax, Size= 70x67", Mag V= 13.26, SB= 14.3

283x - Tiny, faint, round with a condensed core.

NGC 1382
Fornax, Size= 68x65", Mag V= 12.9, SB= 12.9

Faint, small and round at 283x, forms a right angle triangle with a pair of 14th mag stars to the north.

NGC 1380
Fornax, Size= 4.9x1.9', Mag V= 9.93, SB= 13.3

Large, bright and elongated N/S at 283x. Condensed core. A faint star lies at western edge.

NGC 1380a
Fornax, Size= 156x33", Mag V= 12.4, SB= 13.4

A small, faint, diffuse spindle at 283x.

IC 335
Fornax, Size= 108x34", Mag B= 12.9, SB= 12.7

A lovely little spindle at 283x with a relatively high Sfc brightness. Southern edge slightly better defined than the northern edge, bright core region with fainter extensions. Hints of stellaring in core. Located north of the main complex.

NGC 1389
Fornax, Size= 2.1x1.4', Mag V= 11.5, SB= 12.4

Bright, condensed core, slightly elongated NE/SW. A mag 10 star lies 3' north.

NGC 1386
Fornax, Size= 3.1x1.5', Mag V= 11.23, SB= 14.4

Bright, stellar core, small, round. Two faint mag 14 stars lie 2' NW of galaxy. Lies south of main complex.

NGC 1427
Fornax, Size= 2.8x2.0', Mag V= 10.86, SB= 12.6

Stellar core, Sfc brighness increases towards core with a faint outer haze. Elongated E-W. 1427 may not be a true cluster member as it exhibits a smaller redshift and recessional velocity in relation to the other galaxies.

NGC 1428
Fornax, Size= 1.8x0.8', Mag B= 13.74, SB= 13.9

Small, faint, elongated NW/SE with a stellaring in the core visible. A faint star marks the western end. Located well NE of the main complex.

MCG-06-09-008
Fornax, Size= 61x57", Mag B= 14.8, SB= 14.5

Located on the hypotenuse of a right angle triangle bound by NGC 1381/1387/1379. At 283x, Extremely faint, very small, round, took lots of perseverance to spot.

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ESO 490-41
Canis Major, Size= 2.9x1.1', Mag B= 13.45, SB= 14.5

Faint, small elongated glow at 176x. Better view at 283x.

MCG -05-15-008
Canis Major, Size= 3.0x0.5', Mag B= 13.33, SB= 13.5

Very faint, narrow streak of light at 176x. Better view at higher power using 283x, with a slight brightening of the core visible. A mag ~10 star lies to the SE.

NGC 2292
Canis Major, Size= 4.0x3.5', Mag V= 11.83, SB= 14.4

Part of an interacting system with NGC 2293. The 2292 component appeared very faint and much smaller than 2293 at 283x.

NGC 2293
Canis Major, Size= 4.0x3.2', Mag V= 11.2, SB= 14.6

Large and relatively bright at 283x, with a bright condensed core. Round. Forms an interacting system with 2292.
Spotted a mag 15.3 star just to the NE of galaxy.

NGC 2295
Canis Major, Size= 1.5x0.4', Mag B= 13.56, SB= 12.8

Somewhat faint at 283x, an NE-SW elongated low Sfc brightness patch of haze wedged between two mag 13 stars. Located 4' W of NGC 2292/3.

NGC 1721
Eridanus, Size= 2.2x1.1', Mag V= 12.3, SB= 13.7

283x, Condensed core, slightly elongated NW/SE. Forms part of a close trio with NGC 1725/1728. A Mag 15 star was seen 1' NE of core.

NGC 1725
Eridanus, Size= 1.9x1.2', Mag V= 12.3, SB= 13.6

More diffuse than 1721, round, faintest of 3 with 1721/1728.

NGC 1728
Eridanus, Size= 2.0x0.7', Mag V= 12.9, SB= 13.1

Elongated N-S at 283x, brightest of 3 with 1721/1725, which is odd as it has the lowest V mag, however the SB is higher.

NGC 1723
Eridanus, Size= 3.7x2.3', Mag V= 11.7, SB= 14.6

A faint round glow at 283x. Located between a 10th mag star 2' N, and a 11th mag star 1.3' S. Another 10th mag star lies 3' east.

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Now I had a crack at the rich galaxy cluster Abell 754 in Hydra, however the member galaxies are extremely faint and only the central elliptical was visible.

ABELL 754

2MASX J09083238-0937470
Hydra, Mag B= 14.3

Took lots of perserverance to spot this giant elliptical at the core of Abell 754. Very faint, small at 283x. The galaxy is located 750 million light years away! Not a bad effort me thinks :D Easy to find with several mag 11-14 stars in the area which are usefull for orientation.

[Paddy]

That's a lot of galaxies in a night's viewing! I'm very impressed by your capacity to know which is which - I get so overwhelmed by the sheer number of them in this cluster. Haven't really explored it with the Night Sky Observer's guide yet - the piccies they put in might help me. And I reckon observing a mag 14.3 galaxy at 750 mly in poor seeing with Melbourne close to hand is also quite an achievement. Well done, Sab.

[DavidU]

Another great report. You just have to get that beaut mirror under some really dark skies.

[Dave47tuc]

As per normal my friend very well done:thumbsup:

Me thinks Abell 754 is in the realms of the 18" at main ridge sometime next when you come down :rolleyes:

Bring the 12" to Snake Valley and we can have some fun :thumbsup:

[pgc hunter]

Thanks Patrick! The Fornax Cluster is easy to navigate if you have a detailed map or DSS image...otherwise it's anyone's guess what you're looking at :lol:
MCG-06-09-008 which is a Fornax Cluster member is actually fainter than that elliptical in Abell 754, at Mag 14.8.


Thanks Dave. I've got some big plans for this mirror ;) ;)


Thanks Dave, it's good to hear from you! Yes We really do need to organise an observing session :) I suspect a few members of Abell 754 will be visible in an 18", there are 5 galaxies above 15th magnitude.

[Lismore Bloke]

Hello there PGC!! Good to see another excellent report, you certainly bagged some good galaxies. The Fornax cluster is a great area, although I was really straining my eyesight to see too much detail in them when I last looked, apart from the cores of a few. Cheers, Paul.

[orestis]

Hi pgc ,

Great report of some fantastic galaxies i have only observed 3 of these in detail.NGC 1399,ngc1380 and ngc 1387.

I see you use high magnification on some of these galaxies.must have pretty good conditions.

Thanks for a good read.
orestis;)

[Paddy]

Got out last night with Night Sky Observer's Guide and worked through the cluster. It was very good. First time I could confidently say what I was observing.

[ngcles]

Hi PGC,

An excellent report as usual.

See your comment of NGC 1427. Did you mean 1427 or 1427A?

NGC 1427 is a fairly regular slightly elong elliptical-type eg that has an R.V about the same (ie +1300 to +1500 km/sec-odd) as most of the galaxies in the cluster and is a presumed member. Your description more closely describes this eg.

NGC 1427A is a bit different. It is a dwarf irregular not unlike the LMC but is somewhat elongated, dissrupted and undergoing a bot of a star-burst. It has an R.V of about +2100km/sec which would ordinarily place it in the background to the cluster, but ... it is in fact a member. It's peculiar R.V is pretty much due to its very fast in-fall to the centre of the cluster (from our side) where in time, gravitational tidal forces from the supergiant galaxies near centre and ram-pressure from the intergalactic medium it is rocketing though will ultimately tear it apart.

A quite interesting eg!

http://apod.nasa.gov/apod/ap050304.html


Best,

Les D

[pgc hunter]

G'day Les

It was NGC 1427 I observed. I attempted to find NGC 1427a, but could not see it. Looking at DSS images, it has an extremely low surface brightness. I doubt I would be able to see this from even a dark sky location.

http://messier45.com/cgi-bin/dsdb/dsb.pl?str=ngc+1427a

cheers