Observing Report 12/3/10 – 16/3/10

[barx1963 (Malcolm)]

Observing Report 12/3/10 – 16/3/10
All observations made using Dobsonion mounted 305mm Newtonian reflector at f/5. Eyepieces use are 32mm (47x) 24mm Panoptic (67x) 13mm Nagler T6 (115x) or 13mm Nagler with Barlow (230x)
Charts Uranometria 2000 (2nd ed.)
Thanks to Les Dalrymple (NGCles) for his suggestions in his Aust S&T column in the March Edition.
Observations 12/3. Seeing good, transparency fair.
NGC 2903 (Hartung 348) Galaxy in Leo.
Easy to find Galaxy. Located Epsilon Lenis by naked eye. There are 2 mag 6.5 stars about 20’ away to south that form a triangle with Epsilon Leonis. These point roughly at Lambda Leonis which is mag 4.5 reddish star 3deg from Epsilon slightly south of p. 2 faint stars mags 7/7.5 are about 1deg to south. Target is visible within same field at 67x as faint elongated glow running roughly NS. Core is bright and appears “off centre” which agrees with Hartungs description as being closer to the f edge. Low position is not conducive to detailed examination of structure.
NGC 3379 (M105) NGC 3384 (Hartung 400) and NGC 3389. Galaxy group in Leo.
NGC 3379 previously observed with 8” Dobsonion. Companions 3384 and 3389 were not visible on that occasion.
From Regulus moved Nf 2.5deg to 37 Leonis the f to 46 Leonis approx mag 6 star. Then 3.5deg in f to mag5.5 52 Leonis, then scan south about 1.5deg to pair of faint stars just visible in finder.. Northernmost star is a mag 8 wide double. Group is 0.5deg in f. NGC 3379 is clear with bright nearly stellar core and fairly large. NGC 3384 is just to f and in same field as 3379, similar to 3379 but with some evidence of extended arms. NGC 3389 is a very faint smudge just to south. No clear core, some structure in arms.
NGC 3628 (Hartung 417), NGC 3623 (M65 and Hartung 414) NGC 3627 (M66 and Hartung 416). The Leo Triplet. Galaxy group in Leo.
NGC 3623 and NGC 3627 previously observed with 8” Dobsonion. NGC 3628 was not visible on that occasion.
From Theta Leonis move 2deg south to 73 Leonis (Mag 5). Two mag6.5 stars 1deg to south form a right angle triangle with mag 7 star 0.8deg to f. Targets are clustered around this star. NGC 3627 appears the brightest and is rounder, although brightest part appears elongated and almost “blade like”. NGC 3623 is slightly smaller and more elongated with some mottling. NGC 3628 is large faint and narrow running pf. All 3 lie within field at 67x.
NGC 2775 (Hartung 333) Galaxy in Cancer.
Located Zeta Hydrae by naked eye. Moved Nf to pair of mag 6/7 stars then similar distance to 0.5deg wide line of 3 stars running pf. From f star move S about 0.5deg. Faint elliptical glow with very bright core.
NGC 3699 (Hartung 421) Planetary Nebula in Centaurus.
From O1 and O2, an obvious pair about 3deg f from naked eye cluster NGC 3532, scan 0.5deg to Sp until faint glow detected. OIII filter showed improved contrast. Little structure obvious but nebula appears slightly elongated.
NGC 3581,2 (Hartung 408) Bright Nebula in Carina.
From NGC 3532 move just p of south to open cluster NGC 3572 then about 1deg south. Nebula easily picked out at low power. UHC filter revealed much structure including some dark patches. Clear “loop” on p side appears to surround dark nebula NGC 3576.
NGC 3603 (Hartung 409) Open cluster with nebulosity in Carina.
About 1 field at 115x to f side of NGC 3581. Small compact glow. UHC filter makes view better. Some stars but distinct nebulosity. Hartung describes as a “curious” object.
Observations 13/3. Seeing fair, transparency poor (smoke).
NGC 5102 Galaxy in Centaurus.
Located Iota Centauri by naked eye. Target is just to f side. It sits next to a mag 8.5 star about 15’ f of Iota. Small but with a clear core and just a suggestion of elongation.
NGC5236 (M83 and Hartung 530) Galaxy in Hydra.
Locate wide triangle consisting of 1,2 and 3 Centauri. Follow line of 1 and 2 Centauri about 4deg to Nf to mag 5.5 star which has a mag 7 star 15’ away to Sf. Target is 30’ to Sf of first star. Very large with bright dense core. Poor transparency hid much of the spiral structure but it could be detected with averted vision. Inner part is elongated possibly suggestive of a bar.
NGC 4598 (M68 and Hartung 479) Globular Cluster in Hydra.
From Beta Corvii moved just f of south 4deg to a mag 6 star. Target lies 40’ Nf of this star. Fairly large globular but not overly bright. Needs at least 115x to resolve stars. Seems to have a “halo” of slightly brighter stars that a probably foreground stars.
Observations 16/3. Seeing fair, transparency very poor (smoke).
NGC 5617 (Hartung 571) Open Cluster in Centaurus.
From Alpha Centauri moved in p about 40’ to a wide equilateral triangle of mag 7.5 and 8 stars about 20’ wide. This points at cluster about 30’ away to p. Smnall and faint, but very poor transparency may have affected view. Has a very small triangle og mag 9 stars to south and a wide group og 5 or 6 stars to north.

Malcolm

[pgc hunter]

Great report , makes we want to get out there but impossible with this typical sub arctic tundra climate. Did you pick out the dust lane in NGC 3628?

Also shame about the DSE ruining your session, I have noticed brown murk aswell in recent days. Good on 'em for choosing the hottest days to carry out their torching. Hopefully they manage to not set alight entire national parks this season.

[ngcles]

Hi Malcolm,

Thanks for taking the time to post your observations I certainly enjoyed them. Big fan of NGC 2903 myself. It is 20.5 million ly away but despite that, an 18" shows its largest star-cloud -- NGC 2905 a little north of the centre and the core region looks mottled/blotchy. I've spotted this galaxy from far outer suburbia with 10x50s. I covered it in the DSD, March 2007 AS&T.

Glad to hear you liked NGC 3603 which is appreciated better by the mind's eye than the eye -- once you appreciate its gargantuan nature.

Also quite like NGC 5617 -- a nice but often overlooked O.C. Almost exactly between it and Alpha Centauri is the very interesting PNe He 2-111 that is well worth a look too. Not too hard in 31cm from the suburbs


Best

Les D

[Paddy (Patrick)]

Hi Malcolm,

Thanks for another interesting read. I was quite struck by the differences in your current sessions when you compare them to previous obs with an 8" scope.

As Sab says, shame about the smoke.

[pgc hunter]

About 20' SSE of 5617 lies a small rich open cluster of very faint stars called Pismis 19, which on DSS images looks not unlike a loose globular cluster, infact its appearance on images reminds me of M4. It's reddened on DSS images which leads me to believe that it suffers from extinction, but still should interesting to investigate this one in a moderate-large scope.

[orestis]

Great report Malcolm,

I tried to find the leo triplet yesterday night but couldn't seem to find them.Thank you for posting on how you star hopped because this will help me a lot.Thanks.

Regards Orestis

[barx1963 (Malcolm)]

Hey Orestis
When looking for the Leo Triplet. use lowest possible power to get them all in the same FOV, and don't look for 3 galaxies, NGC 3628 is really faint even in a 12" and I couldn't catch it in an 8" last year, but didn't have dark skies.
Focus on finding the 2 Messiers then relax and let the faint one appear in peripheral vision. I had trouble last year 'cause I kept looking for 3!

Malcolm