The Red Square Nebula is a celestial object located in the area of the sky occupied by star MWC 922 in the
constellation Serpens
Serpens ( grc, , , the Serpent) is a constellation in the northern celestial hemisphere. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations designated by the International ...
. The first images of this
bipolar nebula
A bipolar nebula is a type of nebula characterized by two lobes either side of a central star. About 10-20% of planetary nebulae are bipolar.
Formation
Though the exact causes of this nebular structure are not known, it is often thought to impl ...
, taken using the
Mt. Palomar Hale telescope
The Hale Telescope is a , 3.3 reflecting telescope at the Palomar Observatory in San Diego County, California, US, named after astronomer George Ellery Hale. With funding from the Rockefeller Foundation in 1928, he orchestrated the planning, de ...
in
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
, 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.
The explanation proposed by Tuthill and his collaborator James Lloyd of
Cornell University
Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to tea ...
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
SN 1987A was a type II supernova in the Large Magellanic Cloud, a dwarf satellite galaxy of the Milky Way. It occurred approximately from Earth and was the closest observed supernova since Kepler's Supernova. 1987A's light reached Earth on ...
.
[
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.][
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."
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{{DEFAULTSORT:Red Square Nebula
Protoplanetary nebulae
Serpens (constellation)
B(e) stars