Al Bustan 


IC5146 - Cocoon
M5 - NGC5904
M8 - Lagoon Nebula
M16 - Eagle Nebula
M20 - Trifid
M27 - Dumbbell
M31 - Andromeda
M33 - Pinwheel
M42 - Orion
M45 - The Pleiades
M51 - Whirlpool
M57 - Ring
M63 - Sunflower
M64 - Black-Eye
M65 - NGC3623
M67 - NGC2682
M98 - NGC4192
M99 - Pinwheel
M100 - NGC4321
M101 - NGC5457
M104 - Sombrero
M105 - NGC3379
M106 - NGC4258
C/2004 Q2 - Machholz
NGC 891
NGC2024 - Flame
NGC2244 - Rosette
NGC6960 - Veil
The Mice - NGC4676






(Planetary Nebulae)


Discovered by Charles Messier in 1764.

The Dumbbell Nebula Messier 27 (M27, NGC 6853) is perhaps the finest planetary nebula in the sky, and was the first planetary nebula ever discovered.

On July 12, 1764, Charles Messier discovered this new and fascinating class of objects, and describes this one as an oval nebula without stars. The name "Dumb-bell" goes back to the description by John Herschel, who also compared it to a "double-headed shot."

We happen to see this one approximately from its equatorial plane (approx. left-to-right in our image); this is similar to our view of another, fainter Messier planetary nebula, M76, which is called the Little Dumbbell. From near one pole, it would probably have the shape of a ring, and perhaps look like we view the Ring Nebula M57.

This planetary nebula is certainly the most impressive object of its kind in the sky, as the angular diameter of the luminous body is nearly 6 arc minutes, with a faint halo extensing out to over 15', half the apparent diameter of the Moon (Millikan 1974). It is also among the brightest, being at most little less luminous with its estimated apparent visual magnitude 7.4 than the brightest, the Helix Nebula NGC 7293 in Aquarius, with 7.3, which however has a much lower surface brightness because of its larger extension (estimates from Stephen Hynes); it is a bit unusual that this planetary is only little fainter photographically (mag 7.6). The present author (hf) was surprized how fine this object was seen in his 10x50 binoculars under moderately good conditions !

As measured by Soviet astronomer O.N. Chudowitchera from Pulkowo (and mentioned by L.H. Aller, Glyn Jones and Vehrenberg), the bright portion of the nebula is apparently expanding at a rate of 6.8 arc seconds per century, leading to an estimated age of 3,000 to 4,000 years, i.e. the shell ejection probably would have been observable this time ago (it actually happened earlier as the light had to travel all the distance of perhaps about 1000 light years). She estimated the distance somewhat short at only about 490 ly. Another estimate, given by Burnham, has obtained a rate 1.0 arc seconds per century, and an estimated age of 48,000 years.

The central star of M27 is quite bright at mag 13.5, and an extremely hot blueish subdwarf dwarf at about 85,000 K (so the spectral type is given as O7 in the Sky Catalog 2000). K.M. Cudworth of the Yerkes Observatory found that it probably has a faint (mag 17) yellow companion at 6.5" in position angle 214 deg (Burnham).

As for most planetary nebulae, the distance of M27 (and thus true dimension and intrinsic luminosity) is not very well known. Hynes gives about 800, Kenneth Glyn Jones 975, Mallas/Kreimer 1250 light years, while other existing estimates reach from 490 to 3500 light years. Currently, investigations with the Hubble Space Telescope are under work to determine a more reliable and acurate value for the distance of the Dumbbell Nebula.

Adopting our value of 1200 light years, the intrinsic luminosity of the gaseous nebula is about 100 times that of the Sun (about -0.5 Mag absolute) while the star is at about +6 (1/3 of the Sun) and the companion at +9..9.5 (nearly 100 times fainter than the Sun), all in the visual light part of the electromagnetic spectrum. That the nebula is so much brighter than the star shows that the star emits primarily highly energetic radiation of the non-visible part of the electro-magnetic spectrum, which is absorbed by exciting the nebula's gas, and re-emitted by the nebula, at last to a good part in the visible light. Actually, as for almost all planetary nebulae, most of the visible light is even emitted in one spectral line only, in the green light at 5007 Angstrom (see our planetary nebula description) !

By comparing images of the Dumbbell Nebula M27, Leos Ondra has discovered a variable star situated in the very outskirts of the nebula which he called Goldilocks' Variable. This variable can be found in some of our images, namely those of Jack Newton, Peter Sütterlin and (faintly) David Malin's INT photo, as well as one of the images by John Sefick. Other images such as the one in this page don't show this star, proving its variability.

About 2deg to the West of M27 is inconspicuous open cluster NGC 6830, containing about 20-30 widely scattered stars; this cluster is about 5500 ly distant.

(Credits to SEDS - Students for the Exploration and Development of Space)


Observer´s Log

Planetary Nebula
Dumbbell Nebula
NGC 6853
Other description: Planetary nebula irregular.
Constellation: Vul
Dreyer description: A magnificent (or otherwise interesting) object!, very bright, very large, binuclear, irregular extended (Dumbbell); = M27.
Magnitude: 8.1
RA: 19h 59m 48.6s Dec: +22°43'50"
RA: 19h 59m 36.0s Dec: +22°43'00" (Epoch 2000)
Hour angle: -01h 26m 32.0s Air mass: 1.10







Number of Frames: 9

Exposure:  180s ISO 800

Equipment: Meade LX200_12", f/10, Canon EOS300D camera in prime focus

Date: 04-08-12

Reduced, aligned and processed with ImagesPlus.






Number of Frames: 7

Exposure:  600s ISO 800

Equipment: Meade LX200_12", f/10, Canon EOS300D camera in prime focus

Date: 05-09-13

Reduced, aligned and processed with ImagesPlus. Final processing with Photoshop CS.






Number of Frames: 7

Exposure:  600s ISO 800

Equipment: Takahashi FS-102NS, f/8, Canon EOS300D camera in prime focus

Date: 05-10-18

Reduced, aligned and processed with ImagesPlus.







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This site was last updated 2019-02-12                                                                                                          Site created and maintained by Jorge Lázaro