SN 1006

From Wikipedia, the free encyclopedia

**Supernova SN 1006**
Observation data (Epoch ?)

Supernova type	Type Ia
Remnant type	Shell
Host Galaxy	Milky Way
Constellation	Lupus
Right ascension	15^h 2^m8^s
Declination	-41° 57′
Galactic coordinates	G.327.6+14.6
Discovery Date	May 1, 1006
Peak magnitude (V)	-7.5
Physical characteristics
Progenitor	Unknown
Progenitor type	Unknown
Colour (B-V)	some sources cite yellowish at visible spectrum
Notable features	Brightest supernova in recorded history, and therefore most described of the pre- telescopic era

The 1006 supernova as astronomer Tunc Tezel imagines it to have been seen from a spot in what is now Turkey.

SN 1006 was a supernova, widely seen on Earth beginning in the year 1006 AD. It was the highest relative magnitude stellar event in recorded history. First appearing in the constellation of Lupus between April 30 and May 1 of that year, this "guest star" was described by observers in Switzerland, Egypt, Iraq, China, Japan, and possibly North America.

[edit] Historic description

The Chinese left us the most complete historical description of the supernova. According to Songshi in the section of 56 and 461, the star was seen on May 1, 1006 which appeared to the south of constellation Di, east of Lupus and one degree to the west of Centaurus. It was equal to that of half a moon and shone so brightly that the objects on ground could be seen [i.e. at night]. During September, it went below the horizon following the rotation of the heavens. By December, it was again sighted in the constellation Di. The Chinese astrologer Zhou Keming, who was on his return to Kaifeng from his duty in Guangdong, interpreted the star to the emperor on May 30 as an auspicious star, yellow in colour and brilliant in its brightness, that would bring great prosperity to the state over which it appeared.

The Egyptian astrologer Ali bin Ridwan, writing in a commentary on Ptolemy's Tetrabiblos, has left us another historical description of the supernova. He says that the object was 2-1/2 to three times as large as the disc of Venus, and about one-quarter the brightness of the Moon, and, like all other observers, says that the star was low on the southern horizon. Monks at the Benedictine abbey at St. Gall broadly corroborate bin Ridwan's observations as to magnitude and location in the sky, additionally writing that "[i]n a wonderful manner this was sometimes contracted, sometimes diffused, and moreover sometimes extinguished." This last is often taken as proof that the supernova was of Type Ia. Some sources state that the star was bright enough to cast shadows; it was certainly seen during daylight hours for some time, and the modern-day astronomer Frank Winkler has said that "in the spring of 1006, people could probably have read manuscripts at midnight by its light."

There appear to have been two distinct phases in the early evolution of this supernova. There was first a three-month period at which it was at its brightest; after this period it diminished, then returned for a period of about eighteen months. Most astrologers interpreted the event as a portent of warfare and famine.

A petroglyph of the Hohokam has been discovered which may be the first known North American representation of the supernova.[1]

[edit] The Supernova Remnant of SN 1006

The associated supernova remnant from this explosion was not identified until 1965, when Doug Milne and Frank Gardner used the Parkes radio telescope to demonstrate that the previously known radio source PKS 1459-41, near the star beta Lupi, had the appearance of a 30-arcminute circular shell.[2] Over the next few years, both X-ray and optical emission from this remnant were also detected. The supernova remnant of SN 1006 has an estimated distance of 2.2 kiloparsecs, making it approximately 20 parsecs in diameter. As expected for the remnant of a Type Ia supernova, no associated neutron star or black hole has been found.