FH Serpentis (Nova Serpentis 1970) was a

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 ...

, which appeared in the

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 ...

Serpens Serpens () is a constellation in the northern celestial hemisphere. One of the 48 constellations listed by the 2nd-century astronomer Ptolemy, it remains one of the 88 modern constellations designated by the International Astronomical Union. It ...

in 1970. It reached

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 ...

4.4. It was discovered on February 13, 1970 by

Minoru Honda was a Japanese astronomer. Starting in 1937, Honda worked for Issei Yamamoto was a Japanese astronomer and professor at Kyoto University. In 1920, he became first president of the . He was director of the Kwasan Observatory in Kyoto. Hono ...

located at Kurashiki, Japan. Other astronomers later studied this nova, and calculated its distances based on the decay time of its light curves. Nova Serpentis was also observed by the NASA space observatory OAO-2 Stargazer, active from 1968 to 1973. The nova was important for science because it was one of the first to be observed in multiple wavelength bands including, infrared, visible, ultra-violet, and radio. One of the observations that stood out was that it became brightest in the infrared 100 days after it was first discovered. FHSerNebulaExpanding

A small

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 ...

(

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 ...

) is visible around the star, which resembles a planetary nebula. Santamaria ''et al.'' examined images of the nebula taken in 1996 and 2018 and found that the shell is clearly expanding. It is slightly elliptical, with major and minor axes of 12.4×10.6 arc seconds (as of 2018) expanding at a rate of 0.125×0.109 arc seconds per year, implying a physical expansion rate of 630×540 km/sec.

References

{{DEFAULTSORT:FH Serpentis Novae Serpens 1970 in science Serpentis, FH Nova remnants