|
|
|
|
SN 1572
|
| |
|
| |
Historic DescriptionThe appearance of the Milky Way supernova of 1572 was perhaps one
of the two or three most important events in the history of astronomy.
The "new star" helped to shatter stale,
ancient models of the heavens
and to inaugurate a tremendous revolution in astronomy that began with
the realized need to produce better astrometric star catalogues (and thus
the need for more precise astronomical observing instruments). The supernova
of 1572 is often called "Tycho's supernova", because of the extensive work
that Tycho Brahe (1573, 1602, 1610) did in both observing the new star and
in analyzing his own observations and those of many other observers. But
Tycho was not even close to being the first to observe the 1572 supernova,
although he was apparently the most accurate observer of the object (though
not by much over some of his European colleagues like Wolfgang Schuler,
Thomas Digges, John Dee and Francesco Maurolico).
The more reliable contemporary reports state that the new star itself
burst forth sometime between 1572 November 2 and 6, when it rivalled Venus
in brightness.
Discussion
Ask a question about 'SN 1572' Start a new discussion about 'SN 1572' Answer questions from other users |
Timeline
Encyclopedia
Historic DescriptionThe appearance of the Milky Way supernova of 1572 was perhaps one
of the two or three most important events in the history of astronomy.
The "new star" helped to shatter stale,
ancient models of the heavens
and to inaugurate a tremendous revolution in astronomy that began with
the realized need to produce better astrometric star catalogues (and thus
the need for more precise astronomical observing instruments). The supernova
of 1572 is often called "Tycho's supernova", because of the extensive work
that Tycho Brahe (1573, 1602, 1610) did in both observing the new star and
in analyzing his own observations and those of many other observers. But
Tycho was not even close to being the first to observe the 1572 supernova,
although he was apparently the most accurate observer of the object (though
not by much over some of his European colleagues like Wolfgang Schuler,
Thomas Digges, John Dee and Francesco Maurolico).
The more reliable contemporary reports state that the new star itself
burst forth sometime between 1572 November 2 and 6, when it rivalled Venus
in brightness. The supernova remained
visible to the naked eye into 1574, gradually fading until it disappeared
from view.
The Supernova Remnant of SN 1572Radiological DetectionThe search for a supernova remnant was negative until a half-century
ago, when Hanbury Brown and Hazard (1952) reported a radio detection
at 158.5 MHz. This was confirmed at wavelength 1.9 m by Baldwin and
Edge (1957), and the remnant was also identified tentatively in the
second Cambridge radio-source catalogue as object "2C 34" and identified
more firmly as "3C 10" in the third Cambridge list (Edge et al. 1959).
There is no dispute that 3C 10 is the remnant of the supernova observed
in 1572-1573.
Following a review article by Minkowski (1968), the designation 3C 10
appears to be that most commonly used in the literature when referring
to the radio remnant of B Cas (though some authors use the tabulated Galactic
designation G120.7+2.1 of Green 1984, and many authors commonly refer
to it as "Tycho's supernova remnant" --- somewhat of a misnomer, as Tycho
saw the pointlike supernova, not the expansive radio remnant). Because
the radio remnant was reported before the optical supernova-remnant wisps
were discovered, the designation 3C 10 is used by some to signify the remnant
at all wavelengths.
SN 1572 is associated with the radio source G.120·1+1·4. It has an apparent diameter of 7.4 arc minutes, and is located approximately 7,500 light years from our Solar system.
Optical DetectionThe supernova remnant of B Cas was discovered in the 1960s by scientists with a
Palomar Mountain telescope as a very faint nebula. It was later photographed by a telescope on the international ROSAT spacecraft. The supernova was probably of Type Ia, in which a white dwarf star has accreted matter from a companion until it reaches the Chandrasekhar limit and explodes. This type of supernova does not typically create the spectacular nebula more typical of Type II supernovas, such as SN 1054 which created the Crab Nebula. A shell of gas is still expanding from its center at about 9,000 km/s.
Discovery of the Companion StarIn October 2004, a letter in Nature reported the discovery of a G2 star, similar in type to our own Sun. It is thought to be the companion star that contributed mass to the white dwarf that ultimately resulted in the supernova. A subsequent study, published in March 2005, revealed further details about this star: labeled Tycho G, it was likely a main sequence star or subgiant prior to the explosion, but had some of its mass stripped away and its outer layers shock-heated from the effects of the supernova. Tycho G's current velocity is perhaps the strongest evidence that it was the companion star to the white dwarf, as it is traveling at a rate of 136 km/s, which is more than forty times faster than the mean velocity of other stars in its stellar neighbourhood.
See also
External links
|
| |
|
|
