DQ Herculis, or Nova Herculis 1934, was a slow, bright

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

occurring in the northern

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

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 Gr ...

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 those with an outburst brightness visible t ...

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 Irradiance, brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction (astronomy), ...

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

binary star A binary star or binary star system 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 as separate stars us ...

system consisting of a

white dwarf A white dwarf is a Compact star, stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very density, dense: in an Earth sized volume, it packs a mass that is comparable to the Sun. No nuclear fusion takes place i ...

primary with an estimated 60% of the

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

and a

red dwarf A red dwarf is the smallest kind of star on the main sequence. Red dwarfs are by far the most common type of fusing star in the Milky Way, at least in the neighborhood of the Sun. However, due to their low luminosity, individual red dwarfs are ...

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) a ...

of the pair is inclined 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 Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

, 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 those with an outburst brightness visible to ...

stars called intermediate polars. 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 most frequently a star. Friction, uneven irradiance, magnetohydrodynamic effects, and ...

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 Science Biology * Seashell, a hard outer layer of a marine ani ...

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 emission n ...

, similar in appearance to a

planetary nebula A planetary nebula 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 unrelated to planets. The ...

. 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 university, private research university in Cleveland, Ohio, United States. It was established in 1967 by a merger between Western Reserve University and the Case Institute of Technology. Case ...

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

Superman Superman is a superhero created by writer Jerry Siegel and artist Joe Shuster, which first appeared in the comic book ''Action Comics'' Action Comics 1, #1, published in the United States on April 18, 1938.The copyright date of ''Action Comics ...

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