Observing Report 8/12/10

[barx1963]

Despite my earlier pessimism, managed to get a couple of productive hours in last night

Observing Report 8/12/10


All observations made using Dobsonion mounted 305mm Newtonian reflector at f/5. Eyepieces use are 34mm Meade 4000(44x) 24mm Panoptic (67x) 13mm Nagler T6 (115x) or 13mm Nagler with Barlow (230x)

Charts - Uranometria 2000 (2nd ed.) Data derived from Uranometria (2nd ed) Deep Sky Field Guide.

Observations 3/12. Seeing good, transparency fair. Some Light Pollution as usual

NGC 1566 Galaxy in Dorado
RA 13 16 00.9 Dec -02 25 39 Mag(V)13.0 Dim’ 1.5x1.0 SB 13.3 Class (R’)SB(rs)00 pec

Locate Alpha Doradus by naked eye. There is a 1 deg wide equilateral triangle of mag 5/6 stars about 2deg to Np. Follow line of 2 p stars to S about 50’ to a mag 8 star. Galaxy lies just f of it. A very faint mag 12 star is superimposed of f edge of galaxy. Target is fairly large, appears to have a bar running NS. Knots in outer envelope evident with averted vision.

NGC 1617 Galaxy in Dorado
RA 04 31 40.3 Dec -54 36 12 Mag(V)10.4 Dim’ 4.3x2.1 SB 12.7 Class SB(s)a

Lies about 20’ Np of Alpha Doradus. Core easily seen. At higher power (113x) and with averted vision, there is a suggestion of a large spindle shape with an EW orientation. Bracketed by 3 faint stars estimated mag 11-12. IC2085 lies nearby but not located.

NGC 1672 Galaxy in Dorado
RA 04 45 42.2 Dec -59 14 41 Mag(V)9.7 Dim’ 6.6x5.5 SB 13.4 Class SB(s)b II

From Kappa Doradus, move 40’ to Nf to a mag 6.5 star. Galaxy lies about 10’ to p. Bright stellar like core with faint outer envelope. Some spiral structure appeared evident with averted vision.

NGC 2243 Open Cluster in Canis Major (December Challenge object)
RA 06 29 35.0 Dec -31 17 00 Mag9.4 Diam’ 8.3 No. of Stars 368 Mag Brightest Star 11.8 Type cl Open Cluster

Locate Zeta Canis Majoris, about 2.5deg to Sp is a wide pair of Lambda and IY Canis Majoris. Cluster lies just p of a mag 7.5 about 1deg 10’ to N. A faint haze of starlight with maybe 3 mag 11 stars bracketing it. A number of similar brightness stars appear within cluster itself which may be foreground stars.

NGC 1261 Globular Cluster in Horologium (December Challenge object)
RA 03 12 15.3 Dec -55 13 01 Total Vm 8.3 Brightest Star Vm 13.5 HB Vm 16.8 Diam’ 6.8 Conc Class 2

Locate wide double Zeta Reticuli, proceed via Mu Horologii, then via TW Horologii. Cluster lies 2deg due N. Easily visible at low power. Fairly large with an even glow with no obvious core.
NGC 1252 Open Cluster in Horologium
RA 03 10 56.0 Dec -57 46 00 Diam’ 9 No. of Stars 18 Mag Brightest Star 6.7Type ast Asterism

Mag 6.5 star 40’ to Sp of TW Horologii. Very loose open cluster with no central condensation. Onlu about 7/8 stars clearly visible.

NGC 1851 Globular Cluster in Columbo (December Challenge object)
RA 05 14 06.3 Dec -40 02 50 Total Vm 7.1 Brightest Star Vm 13.2 HB Vm 16.1 Diam’ 12 Conc Class 2

Very bright GC with dense core. Averted vision reveals a very large outer shell that dissipates into easily resolved stars of maybe 14/15 mag. This agrees with Uran 2000 data and notes by Gottlieb on NGC/IC project.

NGC 1808 Galaxy in Columba (December Challenge object)
RA 05 07 42.8 Dec -37 30 51 Mag(V)9.9 Dim’ 6.5x3.9 SB 13.3 Class (R)SAB(s)a

About halfway between NGC 1851 and Lambda Caeli. Very bright core, spindle shaped and aligned roughly NS.

NGC 1792 Galaxy in Columba (December Challenge object)
RA 05 05 14.8 Dec -37 58 48 Mag(V)10.2 Dim’ 5.2x2.6 SB 12.9 Class SA(rs)bc II-III

Lies about 20’ to Sp of NGC 1808 and appears as almost a smaller twin of that galaxy. Both appear in same field at 67x. This object is noticeably less bright that its companion.

NGC 2298 Globular Cluster in Puppis (December Challenge object)
RA 06 48 59.2 Dec -36 00 11 Total Vm 9.3 Brightest Star Vm 13.4 HB Vm 16.2 Diam’ 5 Conc Class 6

Lies 3.5deg due S of Kappa Canis Majoris. Small fairly faint, no obvious core. Averted vision helps to “mottle” the cluster. 3 or 4 stars of approximately 13 mag are resolvable.

Malcolm

[Paddy]

More observations - well done Malcolm. Some very interesting bits of sky well described. Was this post or pre foot?

[mental4astro]

That is one great session you had, Malcom.

I'm impressed with the level of detail you were able to describe.

Always nice to see the Challenge objects get a mention too, :).

[barx1963]

Paddy, this is pre foot, just a lucky clear night that wasn't in the forecast!

Mental, glad you liked it, finally able to have a proper go at a challenge.

[Suzy]

Hi Malcom, many thanks, I really enjoyed your beautifully descriptive report, and I also enjoyed the tour to the objects in which you described so well. Fabulous report! :)

[glenc]

Well done Malcolm. :thumbsup:

[astroron]

Great Report Malcolm:thumbsup:, you are doing the report for all of us here on the East coast as we sure as hell are not getting much done up here in "Queensland The Sunshine State":shrug::lol::lol::lol:

[ngcles]

Hi Malcolm,

Very good report Malcolm.



However I think there's a typo here: this is NGC 1566, not NGC 1266. Excellent galaxy, One of the closer Seyfert II galaxies to our own Milky Way the core is quite bright. In 25cm spiral structure is barely visible to experienced observers. IN 31cm (again given the right conditions) is is somewhat easier and in 46cm it is straightforward to see. That star in the halo trips me up almost everytime I see this eg sending me scurrying for the supernova search charts or the DSS.




Pity you didn't see IC 2085 it is a lovely little splinter of mist, though in 30cm it will be at least quite faint.



NGC 1672 is a very nice and underrated eg. I covered it in my column a couple of issues ago now. Very good barred spiral. Hints of spiral structure in 30cm, much clearer with 46cm where you can see the stubby arms coming off the end of the bar.

[/FONT]
[SIZE=3]NGC 1252 Open Cluster in Horologium
RA 03 10 56.0 Dec -57 46 00 Diam’ 9 No. of Stars 18 Mag Brightest Star 6.7Type ast Asterism

Mag 6.5 star 40’ to Sp of TW Horologii. Very loose open cluster with no central condensation. Onlu about 7/8 stars clearly visible.


Yep, it's an astereism and a sparse one at that. There is some speculation that [B]some of its stars may be distantly related to the Hyades cluster (Collinder 50). They apparently share a common proper motion and metallicity (from memory).


Thanks Malcolm !! :thumbsup:


Best,

Les D

[barx1963]

Thanks for your comments Suzy, Ron and Glen.
Suzy, I like to put in the star hopping I used, helps when I go back over my notes to make sure I have the correct object.
Ron, after several months of living vicariously via others reports, it was nice to finally post something.

Les, yes it was a typo sorta, I wrote it down incorrectly in my notes, combination of tired eyes, red lights and late nights I think. I had a quick check on the star in 1566, ya just never know!
As regards IC2085, I think it will have to wait for some really dark skies, I have a fair bit of LP to the south that makes fainter obs in that direction hard to make.
I will look up your comments on 1672 tonight.
Thanks again for your comments