HD 34989 is a blue-white star in the

main sequence In astronomy, the main sequence is a continuous and distinctive band of stars that appears on plots of stellar color versus brightness. These color-magnitude plots are known as Hertzsprung–Russell diagrams after their co-developers, Ejnar Her ...

, of apparent magnitude 5.80, in the constellation of Orion. It is 1700

light-year A light-year, alternatively spelled light year, is a large unit of length used to express astronomical distances and is equivalent to about 9.46 trillion kilometers (), or 5.88 trillion miles ().One trillion here is taken to be 1012 ...

s from the Solar System. The Raspberry Nebula in Orion (SH2-263)

Observation

The star is in the northern celestial hemisphere, but close to the celestial equator; this means that it can be observed from all the inhabited regions of the Earth without difficulty and that it is not visible only in the innermost areas of Antarctica. It appears as circumpolar only far beyond the Arctic polar circle. Its brightness puts it at the limit of visibility to the naked eye, so to be observed without the aid of devices requires a clear, and preferably moonless, sky. The best period for observation in the evening sky is between late October and April from both hemispheres; in February (as at J2000) it is anti-posed from the Sun. In July and August its direction is close to that of the Sun, therefore coinciding with most hours of daylight.

Physical characteristics

It is a blue-white star of the

, having an absolute magnitude of -0.99 and its positive

radial velocity The radial velocity or line-of-sight velocity, also known as radial speed or range rate, of a target with respect to an observer is the temporal rate of change, rate of change of the distance or Slant range, range between the two points. It is e ...

indicates that the star is moving away from the Solar System. The star appears wrapped in an extensive

nebulosity A nebula ('cloud' or 'fog' in Latin; pl. nebulae, nebulæ or nebulas) is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regio ...

that partly shines by reflection and partly by emission. The

reflection nebula Reflection or reflexion may refer to: Science and technology * Reflection (physics), a common wave phenomenon ** Specular reflection, reflection from a smooth surface *** Mirror image, a reflection in a mirror or in water ** Signal reflection, in s ...

is listed as GN 05.19.0 and the

HII region An H II region or HII region is a region of interstellar atomic hydrogen that is ionized. It is typically in a molecular cloud of partially ionized gas in which star formation has recently taken place, with a size ranging from one to hundreds ...

is called Sh2-263. HD 34989 is the ionizing source of this HII-region. In observations with carbon monoxide this corresponds to a circular hole. The star has a size of about 0.118 ± 0.026 milliarcseconds, based on SED fitting.

References

{{DEFAULTSORT:HD 34989 B-type main-sequence stars Orion (constellation) 025041 034989

1763 Events January–March * January 27 – The seat of colonial administration in the Viceroyalty of Brazil is moved from Salvador to Rio de Janeiro. * February 1 – The Royal Colony of North Carolina officially creates Meck ...

Durchmusterung objects