April 30, 1006: Beginning on this evening and continuing throughout the year and beyond, the brightest supernova in recorded history begins to shine. The “guest star” was seen first in the constellation Lupus. Descriptions of the new star appeared in China, Egypt, Iraq, Japan, Switzerland, and possibly in North America. SN1006 (supernova and the year of discovery) has been classified as a Type la supernova meaning it resulted from a violent explosion of a white dwarf star.
Chinese and Egyptian astronomers left the most complete records for our study. The new object was two-and-a-half to three times larger than the disc of Venus and about one-fourth as bright as the Moon. Observers noted the bright light would contract and then diffuse and sometimes completely extinguish. However, there are reports that the bright light was even visible by day and could cast shadows. Modern astronomers believe those alive at the time would have been able to read by the extra bright light cast by the supernova.
Chinese astronomers (viewing the event from a different longitude) claimed the size was half that of the Moon. The supernova appears to have been observed in two distinct phases. The first three months being the brightest; it then diminished only to return for another eighteen months. There is a petroglyph created by the Hohokam in the White Tank Mountain Regional Park (located in Maricopa county, Arizona) which has been interpreted by modern archeologists to be the representation of this event. Other archaeoastronomers disagree with the interpretation.
In 1965, Sough Milne and Frank Gardner were at the Parkes radio telescope and studying a previously known radio source (PKS 1459-41) near the star Beta Lupi. They examined both x-ray and optical emissions and located the source of SN 1006. The distance from Earth is ≈ 2.2 kiloParsecs (a kiloParsec is ≈ 19,000 trillion miles or 1.9 x 1016 miles) making the supernova about 7,200 light-years away. The explosion was ≈ 20 parsecs in diameter. There has been no neutron star or black hole found, which is typical for Type la supernovas. The remnant can still be seen in the electromagnetic spectrum and is about 60 light-years across.
Astronomy’s much more fun when you’re not an astronomer. – Brian May
The history of astronomy is a history of receding horizons. – Edwin Powell Hubble
Until very recently, the heavenly bodies have been investigated only with reference to their position and their laws of motion, and a quarter of a century ago astronomy was little more than celestial topography. – George Phillips Bond
We are probably nearing the limit of all we can know about astronomy. – Simon Newcomb (1835-1909)
Also on this day:
Oh, Hail – In 1888 the deadliest hailstorm in history strikes in India.
Louisiana Purchase – in 1803, President Jefferson bought some land from France.
Father of Our Country – In 1789, George Washington took the Oath of Office and became the first President of the United States.