Author Topic: Planetaries In Puppis  (Read 484 times)

Peter Natscher

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Planetaries In Puppis
« on: March 29, 2017, 10:54:04 AM »
The weather was very good Tuesday night for observing a few planetary nebula with my 16" f/4.5 Dob from the FPOA Observatory on Fremont Peak last night, March 28, 2017.  Temperature was in the 50°F range with no dew, 70%RH, and light occasional wind that didn't affect the seeing.  The SQM by 10pm was 20.94. The seeing was very good at 1 arc-sec and transparency good for viewing my target objects positioned at -14°, -18°, -27° declination.I wanted to capture three small and medium size planetaries lying in Puppis before this winter time constellation disappears for another nine months.  Manually located and observed were:

NGC 2438 Puppis; RA 07 41 Dec -14 44; mag 11; 73"x68".
Moderate size circular ring nebula, ghostly grey in appearance with slightly darker center. Nebula easily spotted at 100X. At 350X, ring appeared uneven in brightness. A faint field star positioned at nebula's dark center but not the central star. Northern side of ring appeared brighter. NPB and OIII narrowband filters similarly enhance nebula shape and ring uneveness.

NGC 2452 Puppis; RA 07 47 Dec -27 20; mag 12.2; 31"x24".
Smaller disk shaped nebula among many field stars, grey in color and spotted at 100X. At 350X, uneven in brightness with north and south ends being brighter.

NGC 2440 Puppis; RA 07 41 Dec -18 12; mag 9.4; 74"x42".
Nebula was easily located at 100X as a small grey hazy oval patch with brighter center. With 350X, much detail was seen within the core as two small bright knots (NW-SE orientation) connected by a "U" shaped bridge bending north-westward between the two.  The elongated halo was finely extended at least 80 min in length. Use of NPB and OIII filters both enhanced the core area and halo.
« Last Edit: March 29, 2017, 07:29:41 PM by pnatscher »


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Re: Planetaries In Puppis
« Reply #1 on: March 29, 2017, 08:40:43 PM »
Excellent sketches, Peter.  Mark McCarthy and I were at Deep Sky Ranch last night and one of the first objects I looked at was NGC 2818A, another planetary superimposed on an open cluster (NGC 2818) in Pyxis. -- sort of a poor man's version of M46 and NGC 2438.


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Re: Planetaries In Puppis
« Reply #2 on: March 30, 2017, 12:03:01 AM »
2818 and 2818a, where the cluster is diffuse enough it's smarter to hunt for the planetary.
For a longish time as I know you know, astronomers scratched their heads over that pair of objects, as it appeared that the PN really was imbedded in the cluster. Serious problem, stars still in an open cluster are way too young to form planetary nebulae. Took years of careful astrometry to show that 2818a is in the foreground.
TAC - astro anarchy at work <*>