A nova is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star that slowly fades over weeks or months. Causes of the dramatic appearance of a nova vary, depending on the circumstances of the two progenitor stars. All observed novae involve white dwarfs in close binary systems. The main sub-classes of novae are classical novae, recurrent novae (RNe), and dwarf novae. They are all considered to be cataclysmic variable stars.
V1974 Cygni or Nova Cygni 1992 was a nova, visible to the naked eye, in the constellation Cygnus. It was discovered visually with 10×50 binoculars on February 19, 1992, by Peter Collins, an amateur astronomer living in Boulder, Colorado. At that time he first noticed it, it had an apparent magnitude of 7.2. Nine hours later he saw it again, and it had brightened by a full magnitude. For this discovery Collins was awarded the AAVSO Nova Award in 1993. The nova reached magnitude 4.4 at 22:00 UT on 22 February 1992. Images from the Palomar Sky Survey taken before the nova event showed identified a possible precursor which had photographic magnitudes of 18 and 17, but the identification of the precursor is not firm.
V1500 Cygni or Nova Cygni 1975 was a bright nova occurring in 1975 in the constellation Cygnus. It had the second highest intrinsic brightness of any nova of the 20th century, exceeded only by CP Puppis in 1942.
V382 Velorum, also known as Nova Velorum 1999, was a bright nova which occurred in 1999 in the southern constellation Vela. V382 Velorum reached a brightness of 2.6 magnitude, making it easily visible to the naked eye. It was discovered by Peter Williams of Heathcote, New South Wales, Australia at 09:30 UT on 22 May 1999. Later that same day it was discovered independently at 10:49 UT by Alan C. Gilmore at Mount John University Observatory in New Zealand.
HR Lyrae or Nova Lyrae 1919 was a nova which occurred in the constellation Lyra in 1919. Its discovery was announced by Johanna C. Mackie on 6 December 1919. She discovered it while examining photographic plates taken at the Harvard College Observatory. The bulletin announcing the discovery states "Between December 4 and 6 it rose rapidly from the sixteenth magnitude or fainter, to a maximum of about 6.5". It was the first nova ever reported in Lyra, and Mackie was awarded the AAVSO gold medal for her discovery. Its peak magnitude of 6.5 implies that it might have been visible to the naked eye, under ideal conditions.
NQ Vulpeculae also known as Nova Vulpeculae 1976, was a nova that appeared in the constellation Vulpecula in 1976. It was discovered visually at 18:20 UT on October 21, 1976 by English amateur astronomer George Alcock. Its apparent magnitude at the time of discovery was 6.5 It reached its maximum brightness of magnitude 6.0 thirteen days after its discovery, at which point it may have been faintly visible to the naked eye. A few days after maximum brightness, it had faded to magnitude 8.3.
V1668 Cygni was a nova that appeared in the northern constellation of Cygnus, situated a couple of degrees to the southeast of the star Rho Cygni. It was discovered by Canadian variable star observer Warren Morrison on September 10, 1978, and reached a peak brightness of around 6.22 apparent magnitude on September 12. The luminosity of the source at this time was about 100,000 times the brightness of the Sun, and likely remained at that level for several months. The expansion velocity of the nova shell was deduced through spectroscopy to be 1,300 km/s.
V838 Herculis, also known as Nova Herculis 1991, was a nova which occurred in the constellation Hercules in 1991. It was discovered by George Alcock of Yaxley, Cambridgeshire, England at 4:35 UT on the morning of 25 March 1991. He found it with 10×50 binoculars, and on that morning its apparent visual magnitude was 5. Palomar Sky Survey plates showed that before the outburst, the star was at photographic magnitude 20.6 and 18.25.
V1494 Aquilae or Nova Aquilae 1999 b was a nova which occurred during 1999 in the constellation Aquila and reached a brightness of magnitude 3.9 on 2 December 1999. making it easily visible to the naked eye. The nova was discovered with 14×100 binoculars by Alfredo Pereira of Cabo da Roca, Portugal at 18:50 UT on 1 December 1999, when it had a visual magnitude of 6.0.
QU Vulpeculae, also known as Nova Vulpeculae 1984 Number 2, was the second nova which occurred in 1984 in the constellation Vulpecula. It was discovered by Peter Collins, an amateur astronomer from Cardiff, California at 22:08 UT on 22 December 1984. At the time of its discovery, the nova's apparent magnitude was 6.8. By the next night, Collins reported its brightness had increased to magnitude 5.6, making it visible to the naked eye.
RX Andromedae is a variable star in the constellation of Andromeda. Although it is classified as a dwarf nova of the Z Camelopardalis (UGZ) type, it has shown low-luminosity periods typical of VY Sculptoris stars. However, for most of the time it varies from an apparent visual magnitude of 15.1 at minimum brightness to a magnitude of 10.2 at maximum brightness, with a period of approximately 13 days.
GQ Muscae, also known as Nova Muscae 1983 is a nova in the constellation Musca, which was discovered by William Liller at 03:20 UT on 18 January 1983. At the time of its discovery it was a magnitude ≈7.2 object, and it subsequently faded.
TU Andromedae is a variable star of the Mira type in the constellation Andromeda. It has a spectral type of M5e and a visual magnitude which varies between extremes of 7.6 and 13.5.
AR Andromedae is a dwarf nova of the SS Cygni type in the constellation Andromeda. Its typical apparent visual magnitude is 17.6, but increases up to 11.0 magnitude during outbursts. The outbursts occur approximately every 23 days.
DX Andromedae is a cataclysmic variable star in the constellation Andromeda. It has a typical apparent visual magnitude of 15.5 during the quiescent phase, but becomes brighter during outbursts recurring with a mean cycle length of 330 days, thus is classified as a dwarf nova of the SS Cygni type.
LL Andromedae is a dwarf nova in the constellation Andromeda, discovered during an outburst in 1979. Its typical apparent visual magnitude is 19.4, but undergoes outbursts events when can reach a peak magnitude of 14.3. Since this magnitude is reached during the most powerful outbursts, while less bright outbursts can occur, it is classified as a SU Ursae Majoris variable.
V455 Andromedae is a dwarf nova in the constellation Andromeda. It has a typical apparent visual magnitude of 16.5, but reached a magnitude of 8.5 during the only observed outburst.
LV Vulpeculae, also known as Nova Vulpeculae 1968 no. 1, was the first of two novae in the constellation of Vulpecula which erupted in 1968. It was discovered by George Alcock who observed it from the back garden of his home in Farcet, England, on the morning of 15 April 1968. The next night it was independently discovered by Midtskoven in Norway. It reached a peak apparent magnitude of 4.79 on 17 April 1968. It was visible to the naked eye at the same time HR Delphini was a naked eye object, and the two novae were less than 15 degrees apart on the sky.
V1370 Aquilae, also known as Nova Aquilae 1982, is a nova that appeared in the constellation Aquila during 1982. It was discovered by Minoru Honda of Kurashiki, Japan at 20:30 UT on 27 January 1982. At that time the Sun had moved just far enough from Aquila to allow the nova to be seen in the morning sky. Although it was discovered photographically, its apparent magnitude was 6–7, making it potentially visible to the naked eye under ideal conditions. A possible magnitude 20 progenitor was located on the Palomar Sky Survey prints. Spectra of the object were taken in February 1982 at Asiago Astrophysical Observatory, which confirmed that it is a nova.
IW Andromedae is a binary star system in the northern constellation of Andromeda, abbreviated IW And. It is the prototype of a class of variable stars known as IW And variables, which is an anomalous sub-class of the Z Camelopardalis variables. The brightness of this system ranges from an apparent visual magnitude of 13.7 down to 17.3, which requires a telescope to view. The system is located at a distance of approximately 2,860 light years from the Sun based on parallax measurements.
