Dumbbell Nebula

"M 27" redirects here. For other uses, seeM27.

TheDumbbell Nebula (also known as theApple Core Nebula,Messier 27, andNGC 6853) is aplanetary nebula (nebulosity surrounding a white dwarf) in theconstellation Vulpecula, at a distance of about 1360light-years.^[1] It was the first such nebula to be discovered, byCharles Messier in 1764. At its brightness ofvisual magnitude 7.5 and diameter of about 8arcminutes, it is easily visible in binoculars^[4] and is a popular observing target inamateur telescopes.

Dumbbell Nebula
Emission nebula
Planetary nebula
Dumbbell Nebula (Messier 27) in Vulpecula
Observation data:J2000 epoch
Right ascension	19^h 59^m 36.319^s^[1]
Declination	+22° 43′ 16.312″^[1]
Distance	389+15 −6^[1] pc
Apparent magnitude (V)	7.4^[2]
Apparent dimensions (V)	8.0′ × 5.6′^[3]
Constellation	Vulpecula
Physical characteristics
Radius	1.44+0.21 −0.16^[a] ly
Absolute magnitude (V)	−0.6+0.4 −0.3^[d]

Notable features	Central star radius is among the largest known for a white dwarf.
Designations	NGC 6853,^[1]M 27,^[1] Diabolo Nebula,^[1] Dumb-Bell Nebula,^[1]
See also:Lists of nebulae

The Dumbbell Nebula appears shaped like aprolate spheroid and is viewed from our perspective along the plane of its equator. In 1992, Moreno-Corralet al. computed that its rate of expansion angularly was, viewed from our distance, no more than2.3 arcseconds (″) per century. From this, an upper limit to the age of 14,600 years may be determined. In 1970, Bohuski, Smith, and Weedman found an expansion velocity of31 km/s. Given itssemi-minor axis radius of1.01 ly, this implies that the kinematic age of the nebula is 9,800 years.^[3]^[5]

Like many nearby planetary nebulae, the Dumbbell contains knots. Its central region is marked by a pattern of dark and bright cusped knots and their associated dark tails (see picture). The knots vary in appearance from symmetric objects with tails to rather irregular tail-less objects. Similarly to theHelix Nebula and theEskimo Nebula, the heads of the knots have bright cusps which are localphotoionization fronts.^[5]

The central star, awhite dwarf progenitor, is estimated to have a radius which is0.055±0.02 R_☉ (0.13 light seconds) which gives it a size larger than most other known white dwarfs.^[6] Its mass was estimated in 1999 by Napiwotzki to be0.56±0.01 M_☉.^[6]

Gallery

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Located in the faint constellationVulpecula, within theSummer Triangle.

It can be located in the sky a few degrees north ofγ Sagittae, near the star14 Vulpeculae.

The Dumbbell nebula can be easily seen in binoculars in a dark sky, just above the small constellation ofSagitta.

Dumbbell Nebula, north is diagonal left-up
Dumbbell Nebula (Messier 27) imaged by theVery Large Telescope
Blend of UHC and RGB exposures of M27 taken with moderate level amateur equipment in the center of a capital city
M27 with 5.5" telescope from city suburbs
Skywatcher 120mm ED APO

Notes

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^{^} Radius = distance × sin(angular size / 2) =1240+180
−140^[7] * sin(8′.0 / 2) =1.44+0.21
−0.16 ly
^{^} Semi minor axis = distance × sin(minor axis size / 2) =1240+180
−140^[7] × sin(5′.6 / 2) =1.01+0.15
−0.11 ly
^{^} Kinematic age = semi-minor axis / expansion rate =1.01+0.15
−0.11^[b] ly / 31 km/s =9.56+1.42
−1.04×10¹² km / 31^[3] km/s =3.08+0.46
−0.34×10¹¹ s =9800+1500
−1100 yr
^{^} 7.5 apparent magnitude - 5 × (log₁₀(420+50
−70 pc distance) - 1) =−0.6+0.4
−0.3 absolute magnitude

References

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^^a ^b ^c ^d ^e ^f ^g ^h"M 27".SIMBAD.Centre de données astronomiques de Strasbourg. Retrieved2023-12-31.
^"Messier 27".SEDS Messier Catalog. Retrieved21 July 2024.
^^a ^b ^cO'Dell, C. R.; Balick, B.; Hajian, A. R.; Henney, W. J.; et al. (2002)."Knots in Nearby Planetary Nebulae".Astronomical Journal.123 (6):3329–3347.Bibcode:2002AJ....123.3329O.doi:10.1086/340726.
^"M 27". 2016-10-15.
^^a ^bO'dell, C. R.; Balick, B.; Hajian, A. R.; Henney, W. J.; et al. (2003). "Knots in Planetary Nebulae".Revista Mexicana de Astronomía y Astrofísica, Serie de Conferencias.15:29–33.Bibcode:2003RMxAC..15...29O.
^^a ^bBenedict, G. Fritz; McArthur, B. E.; Fredrick, L. W.; Harrison, T. E.; et al. (2003). "Astrometry with The Hubble Space Telescope: A Parallax of the Central Star of the Planetary Nebula NGC 6853".Astronomical Journal.126 (5):2549–2556.arXiv:astro-ph/0307449.Bibcode:2003AJ....126.2549B.doi:10.1086/378603.S2CID 8562211.
^^a ^bHarris, Hugh C.; Dahn, Conard C.; Canzian, Blaise; Guetter, Harry H.; et al. (2007). "Trigonometric Parallaxes of Central Stars of Planetary Nebulae".Astronomical Journal.133 (2):631–638.arXiv:astro-ph/0611543.Bibcode:2007AJ....133..631H.doi:10.1086/510348.S2CID 18261027.