GK Persei (also Nova Persei 1901) was a bright

nova A nova (plural novae or novas) is a transient astronomical event that causes the sudden appearance of a bright, apparently "new" star (hence the name "nova", which is Latin for "new") that slowly fades over weeks or months. Causes of the dramati ...

first observed on Earth in 1901. It was discovered by

Thomas David Anderson Thomas David Anderson (6 February 1853 – 31 March 1932) was a Scottish amateur astronomer. Life He was born at 28 Saxe-Coburg Place in Stockbridge, Edinburgh, the son of John Anderson. When he was five years old, his father showed him Co ...

, an

Edinburgh Edinburgh ( ; gd, Dùn Èideann ) is the capital city of Scotland and one of its 32 Council areas of Scotland, council areas. Historically part of the county of Midlothian (interchangeably Edinburghshire before 1921), it is located in Lothian ...

clergyman, at 02:40 UT on 22 February 1901 when it was at

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

2.7. It reached a maximum magnitude of 0.2, the brightest nova of modern times until Nova Aquilae 1918. After fading into obscurity at about magnitude 12 to 13 during the early 20th century, GK Persei began displaying infrequent outbursts of 2 to 3 magnitudes (about 7 to 15 times quiescent brightness). Since about 1980, these outbursts have become quite regular, typically lasting about two months and occurring about every three years. Thus, GK Persei seems to have changed from a classical nova like Nova Aquilae 1918 to something resembling a typical

dwarf nova A U Geminorum-type variable star, or dwarf nova (pl. novae) is one of several types of cataclysmic variable star, consisting of a close binary star system in which one of the components is a white dwarf that accretes matter from its companion. Dw ...

-type

cataclysmic variable In astronomy, cataclysmic variable stars (CVs) are stars which irregularly increase in brightness by a large factor, then drop back down to a quiescent state. They were initially called novae (), since ones with an outburst brightness visible to ...

star. Surrounding GK Persei is the Firework nebula, a

nova remnant A nova remnant is made up of the material either left behind by a sudden explosive fusion eruption by classical novae, or from multiple ejections by recurrent novae. Over their short lifetimes, nova shells show expansion velocities of around 1000& ...

first detected in 1902 consisting of an expanding cloud of gas and dust bubbles moving up to 1200 km/s. GKPerLightCurve

GK Persei has precise parallaxes reported from

Gaia DR2 The ''Gaia'' catalogues are star catalogues created using the results obtained by '' Gaia'' space telescope. The catalogues are released in stages that will contain increasing amounts of information; the early releases also miss some stars, espec ...

and

Gaia EDR3 The ''Gaia'' catalogues are star catalogues created using the results obtained by '' Gaia'' space telescope. The catalogues are released in stages that will contain increasing amounts of information; the early releases also miss some stars, espec ...

, but these are thought to be badly affected by the binary nature of the system. The

Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versa ...

has used a different method to derive the distance to GK Persei using nebular expansion velocity and compares that with its own astrometric parallax calculation. This gave a somewhat smaller parallax (larger distance) than the

Gaia In Greek mythology, Gaia (; from Ancient Greek , a poetical form of , 'land' or 'earth'),, , . also spelled Gaea , is the personification of the Earth and one of the Greek primordial deities. Gaia is the ancestral mother—sometimes parthenog ...

measurements.

Properties

Novae consist of a main-sequence to giant star that accretes mass onto a

white dwarf A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very dense: its mass is comparable to the Sun's, while its volume is comparable to the Earth's. A white dwarf's faint luminosity comes fro ...

. The two stars of GK Persei orbit each other with a period of nearly 2 days. The white dwarf, with a mass of , has one of the highest masses measured in a cataclysmic variable. The donor star, having donated much of its mass to the white dwarf, is only despite being a

subgiant A subgiant is a star that is brighter than a normal main-sequence star of the same spectral class, but not as bright as giant stars. The term subgiant is applied both to a particular spectral luminosity class and to a stage in the evolution of ...

star.

Gallery

File:GKPerLocation.png, The location of GK Persei (circled in red) File:Nova Persei 1901.jpg, GK Persei by the 32-inch Schulman Telescope at the Mt. Lemmon Observatory. File:Expanding nebula around GK Persei.gif, Expanding Nebula around GK Persei. Images range from 1953 to 2012. File:Drawing of the first observed light echo.gif, alt=Changing light-echo observed at the time of the 1901 Nova, hand-drawn by G.W. Ritchey at the Yerkes Observatory. First image is from 20 September 1901. Second image (with letters a-f) is from 13 November 1901., Changing light-echo observed at the time of the 1901 Nova, hand-drawn by G.W. Ritchey at the

Yerkes Observatory Yerkes Observatory ( ) is an astronomical observatory located in Williams Bay, Wisconsin, United States. The observatory was operated by the University of Chicago Department of Astronomy and Astrophysics from its founding in 1897 to 2018. Owne ...

References

External links

* http://www.daviddarling.info/encyclopedia/N/Nova_Persei_1901.html * http://lheawww.gsfc.nasa.gov/users/mukai/iphome/systems/gkper.html
GK Persei
from the

AAVSO The American Association of Variable Star Observers (AAVSO) is an international nonprofit organization, founded in 1911, focused on coordinating, analyzing, publishing, and archiving variable star observations made largely by amateur astronomers. ...

APOD: GK Per: Nova of 1901
2011 November 5
GK Persei by Chandra

Video showing the expansion of the nova remnant
{{DEFAULTSORT:GK Persei Novae Nova remnants Perseus (constellation) 1901 in science 19010221 Persei, GK B-type stars Intermediate polars K-type subdwarfs 1057 021629 K-type subgiants