Object Of The Week June 17, 2018: NGC 6302, the Bug Nebula

[wvreeven]

NGC 6302, PK 349+01.1, PNG 349.5+01.0, Bug Nebula

Planetary Nebula

Constellation: Scorpius
RA: 17h13m44.2s
DEC: -37°06'16"

Magnitude: 10.10

Size: 1.2'

This is one of the most famous bipolar planetary nebulae and I am surprised it hasn't been OOTW yet. The white dwarf at the center of the nebula, which was only discovered in 2009, is one of the hottest stars in the Milky Way with a surface temperature exceeding 250,000 K. It has a mass of 0.64 solar masses and is surrounded by a particularly dense equatorial disk composed of gas and dust. The current theory is that this disk has caused the outflow of the star to form the bipolar structure similar to an hour-glass. This bipolar structure is one of the most complex seen in any planetary nebula and shows many of the interesting structures seen in planetary nebulae such as ionization walls, knots and sharp edges to the lobes.

When the Hubble Space Telescope celebrated its 25th birthday, it took this picture of the Bug Nebula

low_25th-gallery-070.jpg

Visually the nebula is very appealing. My notes with my 20" from July 9, 2015, read

At 151x this nebula already is seen easily as an elongated spot with a bright central part. Both OIII and UHC boost the visibility of the nebula with the effect of OIII the largest. The central part is elliptical and is inclined with respect to the rest of the nebula. Both ends show a lot of streamers. Unfortunately the low altitude above the horizon implies bad seeing so probably many of the details are lost.

I am curious who managed to see more details, especially from northern latitudes.


As always,

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

[Bertrand Laville]

Hi All,

at latitude -37°, NGC 6302 raises at 6 or 7° above horizon in my southern Alps.
With a 10" scope it is a hazy spot at low power, and a more hazy patch at high power.

But in namibian skies, at 70° high, NELM 7,0+, SQM 21,8 – 21,9 depending the distance you point at from the dazzling milky way, no chance to see as precisely as the HST, but I could see with a 20" Obsession almost all the details that the 16" hypergraph of the german folks showed.
Detailed report at http://www.deepsky-drawings.com/ngc-6302-2/dsdlang/en

Clear skies
Bertrand

NGC 6302 Spiegel team Hypergraph Tivoli.jpeg


NGC 6302 T508 BL Tivoli Namibie 2008.jpg

[Raul Leon]

Hello, This is my observation of ngc 6302 from 2007; unusual bi-polar nebula; very bright with extensions running east and west; one extension seems longer than the other; dark intrusion towards center observed with averted vision only; UHC filter works fine on it; very interesting nebula ; I used my 14.5 Starstructure dob f/4.3 with a 7mm Nagler 226x UHC filterScan0687.jpg I must revisit this one soon ,it's been quite a while since I've seen it.

[kisspeter]

From our regular observing meadow in Hungary NGC 6302 is at most 5° above the horizon. I didn't even try it. I only took a look at this light polluted patch of sky among the trees with the naked eye longing to see the treasures there are.

As Bertrand wrote from Namibia it's a completely different story. I drew it in June 2012 from Hakos with a 16" (300x, 6mm Planetary):
ngc6302_kisspeter.jpg
And the inverted version:
ngc6302_positive_kisspeter.jpg
That time I didn't have filters so it's unfiltered.

[Howard B]

This is one of my favorite bi-polar planetary nebulae, and has already been mentioned it's really low to the southern horizon for those of us in mid-northern latitudes. I've observed it several times even though the atmospheric murk is hiding many of its details because it still looks pretty awesome. My best view was from the 2015 Golden State Star Party in northern California with my 28-inch scope.

NGC6302_crop.jpg NGC6302_cropinvert.jpg

My notes state the transparency was below normal, the SQM reading was 21.53, and I used both the NPB filter and no filter during this observation. I've always thought it looks more like a barred spiral galaxy than a planetary nebula, but Peter and Bertrand's sketches show what I've been missing!

[Uwe Glahn]

I never tried the PN from my northern latitude (47°N), even when it is possible to observe it between mountains or branches of a tree.

I had my first contact with the PN 2009 in Namibia where I collected observing data for a sketch during two nights.
12", 429x, NELM 7m0+
NGC6302.jpg

Afterwards I'm happy with the observations and sketch, even when the 17-inch and 24-inch shows little more detail.

Last contact was the May on the Gamsberg with the most powerful combination (aperture, transparency, seeing) in Namibia. The 28-inch shows within a few minutes much more details, particular y within the brighter center than the old 12-inch sketch. Very impressive view but without a sketch.