The Seagull Nebula (often mistakenly called IC 2177 [note 1] ) is a complex of emission and reflection nebulae and open star clusters at the boundary of the constellations Unicorn and Canis Major .
| The Seagull Nebula | |
|---|---|
| ionized hydrogen region | |
 | |
| Research history | |
| Designations | IC 2177 , vdB 93 , NGC 2343 , NGC 2353 |
| Observational data ( Age J2000.0 ) | |
| Right ascension | |
| Declination | |
| Distance | 1000 pc |
| Constellation | Unicorn |
The nebula is located at a distance of about 9 ° northeast [note 2] from Sirius (towards Procyon ), in an area rich in young hot blue stars called the Canis Major OB1 star association (originally it was called Canis Major R1 because of the large the number of reflective nebulae [1] ). It can be observed with lateral vision even with good binoculars, while it appears to be a weak elongated halo in the direction of the CER – SE . The shape of the seagull in flight, due to which the nebula got its name, is clearly visible in large telescopes, and takes a length of more than 2 °.
From a physical point of view, the Seagull Nebula is a region of ionized hydrogen in which star formation occurs, as evidenced by the presence of many infrared and x-ray sources associated with young or emerging stars. [2] There are many other small nebulae in the vicinity of the nebula, some of which are reflective, recognizable by their bluish color. In this area, there are also open star clusters, for example, NGC 2353 .
To the east of this complex is another, less extensive and less pronounced nebula - LBN 1036 . Both nebulae are parts of the same molecular cloud , the shape of which is caused by a supernova explosion about 500 thousand years ago. [3] The physical diameter of the cloud is approximately 100 parsecs.
Observation
The Seagull Nebula is located in the northern part of the constellation Canis Major on the border with the Unicorn. She can be easily found about 3 ° degrees northeast of θ of Canis Major , an orange giant of the 4th magnitude, in turn, located north-north-east of Sirius. Even with good binoculars in this area, several star clusters will be distinguishable. In small amateur telescopes with an aperture of ~ 140 mm, the nebula will appear in the form of a faint light band elongated in the direction CER – SW, with some areas, for example, IC 2177 , surrounding the 7th magnitude star HD 53367 and representing the “head” of Chaika, will be slightly brighter. In the photographs, the “wings” of the Seagull will occupy more than 2 ° in length, and in its surroundings one can find a number of other nebulae, for example, LBN 1036 , which is physically part of this complex, as well as several reflective nebulae . [four]
In the middle band of the northern hemisphere, the nebula can be observed in the evening sky from December to April. In areas close to the Arctic Circle , it will be visible near the horizon. In the tropical latitudes of the southern hemisphere, it is located almost at its zenith .
Notes
- ↑ IC 2177 , or vdB 93, represents only the "head" of the Seagull.
- ↑ hereinafter in the article the concepts of “east”, “west”, “north”, etc. are counted relative to the equatorial coordinate system
References:
- ↑ van den Bergh S. A study of reflection nebulae // Astronomical Journal. - 1966. - Vol. 71. - P. 990-998. - DOI : 10.1086 / 109995 . - .
- ↑ Gregorio-Hetem J., Montmerle T., Casanova S., Feigelson ED X-rays and star formation: ROSAT observations of the Monoceros and Rosette molecular clouds // Astronomy and Astrophysics. - 1998. - Vol. 331. - P. 193-210. - .
- ↑ Gregorio-Hetem J. The Canis Major Star Forming Region // Handbook of Star Forming Regions. Volume I, The Northern Sky / Ed. by Bo Reipurth. - Astronomical Society of the Pacific, 2008. - P. 1-26. - ISBN 978-1-58381-670-7 . - . - arXiv : 0808.3812 .
- ↑ Tirion W., Sinnott RW Sky Atlas 2000.0: twenty-six star charts, covering both hemispheres, and seven detailed charts of selected regions. - 2nd ed. - Cambridge University Press, 1998 .-- P. 18 (chart 12). - ISBN 0-933346-87-5 .
Links
- Miller M. http://www.astronet.ru/db/msg/1298463 . Astronomical picture of the day . Astronet (January 11, 2014). Date of appeal September 26, 2014.
- Zolotavkin E. Photo of the week: The Seagull Nebula and its wings . The Big Universe (February 8, 2013). Date of appeal September 26, 2014.
- Jardine K. Seagull (230 ° - 220 °) Region . Our Galactic Region . Galaxy Map. Date of appeal September 26, 2014.