Observing Report with sketches 1-2 Oct 2010 Part 1
Had some unprecedented clear sky activity in Melbourne on Friday Oct 1 and Saturday Oct 2. That particular weekend saw 3 clear nights in a row, which is a new world record for the 4.5 billion year history of Melbourne.
Seeing was exceptionally poor both nights transparency was better on the Friday. Saturday started off a bit hazy, but seemed to improve in the early hours.
This report combines the observations from both days.
Grus, GX, RA 22 13 21 , DEC -46 01 07, Size= 2.8x1' , Mag V= 11.5
267x - Strongly brightens toward center with a quasi-stellar nucleus. Bright, strongly elongated ENE/SSW with fainter extensions stretching out from the core.
Grus, GX, RA 22 15 37 , Dec -45 51 03 , Size= 3x1' , Mag B= 12.6
Grus, GX, RA 22 15 49 , Dec -45 50 49 , Size= 1.8x1.6' , Mag B=12.9
Nice pair of galaxies located 2' SE of a pair of 9th mag stars. NGC 7233 forms an equilateral triangle with the pair. 267x - 7232 brighter of the two galaxies, elongated E-W. 7233 fainter, rounder although a slight E-W elongation was noted. DSS images show the bright core slighted elong E-W, so this confirms my obs. A stellar core was noted. A 3rd galaxy, NGC 7232B lies 4' NNE of the pair but much too faint to see visually.
Sculptor, GX, RA 23 57 49 , Dec -32 35 32 , Size= 9.1x6.6' , Mag V= 9.1
102x - Fairly large hazy smudge, roughly circular. No details seen. Brightens toward core, with the core itself hinting at a stellaring. A mag 12.4 star lies near the galaxy's northern edge.
Grus, GX , RA 23 02 46 , Dec -40 50 10 , Size= 3.7x0.6' , Mag V= 11.9
102x - A thin streak of light, fairly faint. Elongated E-W, a mag 11 star is located at the western end of the galaxy. Set in a relatively rich star field.
Grus, GX, RA 22 55 01 , Dec -39 39 46 , Size= 5.5x2.0' , Mag V= 10.6
41x - Bright, elongated NE-SW. A mag 12 star lies adjacent north of the galaxy's NE end. At 166x the galaxy is seen as a wide streak of light, brightest in the core. SW end appeared slightly brighter than the NE end.
Pavo, GX , RA 21 18 22 , Dec -63 45 42 , Size 3.4x05' , Mag B= 13.3
267x - A small, faint stubby streak elongated NW-SE. Forms an equilateral triangle with a mag 10 and mag 12 stars 4' to the NE and NW. Hint of stellaring in core at 381x. Striking edge on galaxy on DSS images -smaller and fainter version of NGC 891.
Pavo, GX , RA 20 52 07 , Dec -69 12 21 , Size 6.5x1.2' , Mag V= 11.2
166x - A faint, narrow streak of light, much fainter visually than the V mag would suggest, due to low surface brightness.
Tucana, GX , RA 22 47 17 , Dec -65 03 40 , Size 3.1x3.0' , Mag B= 12.1
Tucana, GX , RA 22 47 22 , Dec -65 03 33 , Size 3.0x2.9' , Mag B= 12.2
381x - An excellent very compact pair, accidently swept up while looking for another nearby galaxy! Both galaxies are high surface brightness and were very easy to spot. Visually, the B component is the brightest and largest of the two. It appeared slightly elongated roughly NW-SE, with a mag 12.9 star superimposed on the SE edge of the halo. An elongated bright patch could be seen in the centre. The A component lies approx 1' W of B and is slightly smaller and fainter. The A component is round, with stellar nucleaus. It doesn't show the bright central region that B does, but still features fairly high overall surface brightness. Visually both galaxies are much smaller than the quoted 3' sizes, as those values include tidal streamers that are much too faint to see visually. At the eyepiece the apparent size for both components is about 30".
ABELL S 585
Dorado , GX, RA 06 22 22 , Dec -64 56 06 , Size 1.3x1' , Mag V= 13.1
Dorado , GX , RA 06 21 28 , Dec -64 59 35 , Size 1.1x0.9' , Mag V= 13.2
Dorado , GX , RA 06 21 24 , Dec -64 57 26 , Size 1.4x0.4' , Mag V= 13.6
Dorado , GX , RA 06 21 40 , Dec -65 02 01 , Size 0.8x0.2' , Mag V= 13.9
267x - Four brightest members of rich galaxy cluster Abell S 585 all seen. NGC 2235 is the brightest of the four, is located approx 40' SSW of an 11th mag star. Small, faint and round, with a slight brightening towards the core. NGC 2230 slightly fainter, small and round. 2' to the N lies NGC 2229 which has a higher surface brightness than 2230 and appeared slightly elongated SE-NW. NGC 2233 is the faintest of the four, and was small and faint in the eyepiece with no obvious features.
ABELL S 463
Dorado , GX , RA 04 29 08 , Dec -53 49 12 , Size 1.5x1.0 , Mag V= 13.2
Dorado , GX , RA 04 29 36 , Dec -53 47 14 , Size 0.8x0.7' , Mag B= 15.7
Dorado , GX , RA 04 28 31 , Dec -53 44 19 , Size 1.5'x0.5' , Mag B= 14.76
All observed at 381x - This galaxy cluster is located some 580 million light years away! The largest and brightest member, IC 2082 was easily spotted at 166x. At 381x it appeared moderately faint, not hard to see though. This is actually a binary galaxy, the 2nd member is much to close to resolve visually. PGC 15255 is located about 2.5' E of IC2082 and I caught fleeting glimpses of it at 381x, extremely faint and featureless dust mote. Despite this, it was not too difficult to catch it, due to its high surface brightness. Another 5' to the east lies ESO 157-G036, which, although very faint, showed clear elongation. About 10' NW of IC 2082 is IC 2079, which at 381x was extremely faint and only glimpsed intermittently. This galaxy lies 494 million light years away, so it may infact be a chance foreground object.
attached is a sketch of NGC 253 and IC 5250a/b.
Last edited by pgc hunter; 10-10-2010 at 09:50 PM.
Saab, you do the most amazing obs reports and sketches. Wow, what a great read that was. I can only hope that one day I will come close to your standards. I'm learning so much from your reports and sketches. Bring on part 2 - I can't wait!
Thanks Ron and Suzy. It's been months, but it's good to get out there, poor seeing or not!
Was full clear again last night, but uni today meant no obs
I'm glad to hear you are getting something from my reports and enjoying them Suzy Sometimes when researching the objects I've observed for these reports, even I'm stunned.... like spotting a galaxy 730 million light years away from my suburban backyard.... did not see that coming! That is my new personal distance record for a galaxy.
Lovely detailed descriptions as always Sab. I take it that the mirror is now giving it's best as the cooling and collimation are up to par with the SDM treatment.
Thanks David, glad you enjoyed! My secondary could use a bit of tweaking, but always forget and it's hard to do in the dark! But yeah the observing has greatly improved since the addition of fans and I've noticed a very noticable improvement in the views since conversion to SDM. The reasons for this:
- active cooling
- accurate collimation of both mirrors via laser and cheshire...before the secondary was nearly impossible to adjust and was never sure if both the optical and mechanical alignment was accurate (unlikely)
-collimation stays dead on all night, not lateral mirror shift at all, also the old scope it would wonder up to 10mm from horizon to zenith, this has been reduced to about 1mm.
-Much better mirror cell, the original was unventilated, plus without fans it never reached equilibrium.
I observed M42 during the session and was blown away, like other familar targets it appeared much more vivid, detailed, brighter and fainter stars could be seen than in the old scope.