DQ Herculis, or Nova Herculis 1934, was a slow, 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 dramat ...

occurring in the northern

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the earliest constellation ...

Hercules Hercules (, ) is the Roman equivalent of the Greek divine hero Heracles, son of Jupiter and the mortal Alcmena. In classical mythology, Hercules is famous for his strength and for his numerous far-ranging adventures. The Romans adapted the ...

in December 1934. This

cataclysmic variable star 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 ...

was discovered on 13 December 1934 by J. P. M. Prentice from Stowmarket, Suffolk. It reached peak brightness on 22 December 1934 with an

apparent magnitude Apparent magnitude () is a measure of the brightness of a star or other astronomical object observed from Earth. An object's apparent magnitude depends on its intrinsic luminosity, its distance from Earth, and any extinction of the object's ...

of 1.5. The nova remained visible to the naked eye for several months. This is a

binary star A binary star is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved using a telescope as separate stars, in ...

system consisting of 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 ...

primary with an estimated 60% of the

mass of the Sun The solar mass () is a standard unit of mass in astronomy, equal to approximately . It is often used to indicate the masses of other stars, as well as stellar clusters, nebulae, galaxies and black holes. It is approximately equal to the mass ...

and a

red dwarf ''Red Dwarf'' is a British science fiction comedy franchise created by Rob Grant and Doug Naylor, which primarily consists of a television sitcom that aired on BBC Two between 1988 and 1999, and on Dave since 2009, gaining a cult following. ...

secondary with 40% of the Sun's mass. They orbit each other tightly with a period of . The system shows orbital period variation, possibly due to the presence of a third body. The

orbital plane The orbital plane of a revolving body is the geometric plane in which its orbit lies. Three non-collinear points in space suffice to determine an orbital plane. A common example would be the positions of the centers of a massive body (host) an ...

of the pair is

inclined Incline, inclined, inclining, or inclination may refer to: *Grade (slope), the tilt, steepness, or angle from horizontal of a topographic feature (hillside, meadow, etc.) or constructed element (road, railway, field, etc.) *Slope, the tilt, steepn ...

by an angle of 86.5° to the

line of sight The line of sight, also known as visual axis or sightline (also sight line), is an imaginary line between a viewer/observer/ spectator's eye(s) and a subject of interest, or their relative direction. The subject may be any definable object taken ...

from the

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's sur ...

, causing the white dwarf to undergo a deep eclipse every orbit. DQ Herculis is the prototype for a category of

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 ...

stars called

intermediate polar In astronomy, an intermediate polar (also called a DQ Herculis Star) is a type of cataclysmic variable, binary star system with a white dwarf and a cool main-sequence secondary star. In most cataclysmic variables, matter from the companion sta ...

s. The red dwarf has filled its

Roche lobe In astronomy, the Roche lobe is the region around a star in a binary system within which orbiting material is gravitationally bound to that star. It is an approximately teardrop-shaped region bounded by a critical gravitational equipotential, ...

and matter is being drawn off at the rate of , forming an

accretion disk An accretion disk is a structure (often a circumstellar disk) formed by diffuse material in orbital motion around a massive central body. The central body is typically a star. Friction, uneven irradiance, magnetohydrodynamic effects, and other ...

orbiting the primary. This disk has inferred temperatures ranging from 5,000 to . A bright spot in the inner disk appears to pulsate with a 71-second period. In this class of variables, the white dwarf is magnetized, directing infalling matter onto the magnetic poles. DQHerNebulaExpanding

The

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure Science Biology * Seashell, a hard o ...

of ejected material from the nova outburst is visible as an

emission nebula An emission nebula is a nebula formed of ionized gases that emit light of various wavelengths. The most common source of ionization is high-energy ultraviolet photons emitted from a nearby hot star. Among the several different types of emissio ...

, similar in appearance to a

planetary nebula A planetary nebula (PN, plural PNe) is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives. The term "planetary nebula" is a misnomer because they are unrelate ...

. This roughly elliptical nebula had a size of 32.0 × 24.2 arc seconds as of 2018, and it is expanding at a rate of about 0.16 arc seconds per year.

In popular culture

The nova was one of the brightest objects observable in the night sky. In addition to scientific articles, and received significant coverage in popular news publications. Brad Ricca, an English professor at

Case Western Reserve University Case Western Reserve University (CWRU) is a private research university in Cleveland, Ohio. Case Western Reserve was established in 1967, when Western Reserve University, founded in 1826 and named for its location in the Connecticut Western Reser ...

, has suggested that Nova Herculis may have influenced the development of the origin story of the comic book superhero

Superman Superman is a superhero who appears in American comic books published by DC Comics. The character was created by writer Jerry Siegel and artist Joe Shuster, and debuted in the comic book '' Action Comics'' #1 ( cover-dated June 1938 and pu ...

References

External links

* http://www.daviddarling.info/encyclopedia/N/Nova_Herculis_1934.html {{DEFAULTSORT:DQ Herculis Novae Nova remnants M-type main-sequence stars Intermediate polars Hypothetical planetary systems Hercules (constellation) 1934 in science Herculis, DQ 19341213