Object Of The Week January 29th, 2017 - NGC 2452

[wvreeven]

NGC 2452 - Hen 2-4, PK 243-1.1, PNG 243.3-01.0

Planetary Nebula

Constellation: Puppis
RA: 07 47 26.27
DEC: -27 20 06.6

Mag: 12.60
Mag central star: 17.7

Size: 31" x 24"

The planetary nebula NGC 2452 was discovered during sweep 769 in 1837 by John Herschel from Cape of Good Hope using his 18.7" refractor. Unfortunately I have not been able to find the exact date of the discovery because the dates of the sweeps are not publicly available. By the way, the entry on NGC 2452 in wikipedia states 1847 but this is not correct. That year the book about his observations at Cape of Good Hope, written by John Herschel himself, was published and not the actual discovery itself.

The nebula itself is fairly large and contains a lot of detail. However, due to its southern declination it is as challenging as observing a planet when it is located in Sagittarius. Perhaps even more challenging because of the lower total magnitude and therefore surface brightness.

2461

My notes from March 30, 2016, using my 20" telescope read:

At 320x and 427x visible as a small nebula with a complex structure. At 320x it appears oval with a bright patch at the south end and a slightly fainter patch at the north end with a dark area between them. At 427x it appears round with a bar running north to south and a small dark hole at the center. The south patch again is brightest and seems to be composed of two starlike blobs. The seeing is not very good so all details are smeared out a bit.


As always,

"Give it a go and let us know!
Good luck and great viewing!"

[obrazell]

Wolfgang gives 1 of feb 1837 for the discovery and since he has seen the original sweep notes that is probably right.

Owen

[wvreeven]

Thanks very much Owen! Would you mind revealing where you found that? Or did you simply send him an email? :D

[obrazell]

No in the historical NGC/IC files that you can download from his site it is there.

Owen

[wvreeven]

Hmmm that's where I looked and I couldn't find it. I'll look again. Thanks!

[Howard B]

I have only one observation of NGC 2452, from December 1993:

"NGC 2452/NGC 2453 - Another open cluster/planetary combo (note, I'd just observed M46 and NGC 2438). 2452 was was close to, but not inside the open cluster (2453) and was a roundish, detail-less blob of fuzz (but relatively bright). 2453 was a distinct open cluster, small, with a nice mix of bright and faint stars. 20 inch f/5, 182x."

My notes show the seeing was terrible, which accounts for the lack of detail in the planetary. Given its declination of -27 I'll bet the seeing was downright awful. Another one to add to my re-observe list.

[Steve Gottlieb]

Here's John Herschel's original description for h3100 on 1 Feb 1837. By the way, I include all the NGC discovery dates, as well as most of the original descriptions, at the end of my visual descriptions on the NGC (in the signature below).

"An object whose nature I cannot make out. It is certainly not a star, nor a close double star; but it is not round, and I should call it an oblong planetary nebula, by reason of its decidedly marked though somewhat dim outline, were there not some suspicion of its being double, as if a very close and highly condensed double nebula. It is very small and rather faint, 8" long, 5" broad, and equals a star of 10th mag. In a field with at least 60 or 80 stars [NGC 2453], all sharp and well defined but this.

Four nights later he swept the field again and logged, "Planetary nebula. In a field with, and south of a cluster, and on a rich ground is the undefined object of Sweep 769. It is no doubt a very faint, small, round planetary nebula..."


My own notes read (using an 18"), "Very interesting bipolar appearance at 450x. Appears elongated N-S, ~30"x22", with brighter lobes and rims on the north and south ends. The center appears slightly darker and pinched in. The small open cluster NGC 2453 lies 7' N."

[Uwe Glahn]

Nice PN, unfortunately very low in the sky for Middle Europe.

I had one old sketch with 16", made from an High Alpine place (~47°N). The two main shells were visible, with different sizes and somewhat slightly structure in the shells.
16", 515x, NELM 7m0+, Seeing I-II
2464

Last new moon I had the chance to get very good seeing conditions at an also High Alpine (5100ft) place which were very rare here in the winter. I wanted to revisit the PN since three years and finally got the chance. I was astonished about the details which were visible. With high magnification the double knot structure in the S was the most prominent feature, following from a nearly stellar peak in the NW and a longer section at the N edge.
27", 837x, NELM 6m5+, Seeing II
2465