astro.wikisort.org - Nebula

The Red Square Nebula is a celestial object located in the area of the sky occupied by star MWC 922 in the constellation Serpens. The first images of this bipolar nebula, taken using the Mt. Palomar Hale telescope in California, were released in April 2007. It is notable for its square shape, which according to Sydney University astrophysicist Peter Tuthill, makes it one of the most nearly discrete-symmetrical celestial objects ever imaged.[2]

Red Square Nebula

Reflection nebula
Protoplanetary nebula
Observation data: J2000 epoch
Subtype	bipolar nebula
Right ascension	18h 21m 16.060s[1]
Declination	−13° 01′ 25.69″[1]
Distance	5000[2] ly   (1500 pc)
Constellation	Serpens
Designations	MWC 922[1]
See also: Lists of nebulae

The explanation proposed by Tuthill and his collaborator James Lloyd of Cornell University is that the square shape arises from two cone shapes placed tip-to-tip, as seen from the side. This also explains the "double-ring" structure seen in SN 1987A.[2]

A series of faint spokes radiate from the center of the structure. One possible explanation is that these spokes are shadows cast by periodic ripples or waves on the surface of an inner disk close to the central star.[2]

There is no clear explanation of how the central star could produce the nebula's shape:

Towards the end of their lives, many low-mass stars, like the Sun, slough off their outer layers to produce striking 'planetary' nebulae. But the hot star at the heart of the Red Square nebula, called MWC 922, appears to be relatively massive, suggesting another process formed its signature shape. "How did all this beautiful, crisp structure form?" asks Peter Tuthill of the University of Sydney in Australia. "This is the million dollar question."[3]

Notes

References

External links

• Than, Ker (12 April 2007). "Near-Perfect Symmetry Revealed in Red Cosmic Square". Space.com.
• "Astronomers Obtain Highly Detailed Image of the 'Red Square'". Phys.Org. 13 April 2007.
• Tuthill, Peter G.; Lloyd, J. P. (13 April 2007). "A Symmetric Bipolar Nebula Around MWC 922". Science. 316 (5822): 247. Bibcode:2007Sci...316..247T. doi:10.1126/science.1135950. PMID 17431173.
• NASA Astronomy Picture of the Day: MWC 922: The Red Square Nebula (16 April 2007)
• NASA Astronomy Picture of the Day: MWC 922: The Red Square Nebula (23 March 2011)

На других языках

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- [en] Red Square Nebula

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[es] Nebulosa Roja Cuadrada

Nebulosa Roja Cuadrada es un objeto celeste situado en la zona del cielo ocupado por la estrella MWC 922. Las primeras imágenes de esta nebulosa bipolar, tomadas por el telescopio Hale del Monte Palomar y el telescopio Keck-2 en Mauna Kea, fueron hechas públicas en abril de 2007. Es muy reconocible por su forma cuadrada, que de acuerdo con el astrofísico Peter Tuthill de la Universidad de Sídney, la hacen uno de los objetos celestes más simétricos jamás descubiertos.

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