HD 269810 is a
blue giant
In astronomy, a blue giant is a hot star with a luminosity class of III (giant star, giant) or II (bright giant). In the standard Hertzsprung–Russell diagram, these stars lie above and to the right of the main sequence.
The term applies to a ...
star in the
Large Magellanic Cloud
The Large Magellanic Cloud (LMC), or Nubecula Major, is a satellite galaxy of the Milky Way. At a distance of around 50 kiloparsecs (≈160,000 light-years), the LMC is the second- or third-closest galaxy to the Milky Way, after the ...
. It is one of the
most massive and
most luminous stars known, and one of only a handful of stars with the
spectral type
In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...
O2.
Name
The star's name, HD 269810, comes from the
Henry Draper Catalogue. The serial number 269810 indicates it was published in the extension of the catalogue and is formally referred to as HDE 269810.
Details
HD 269810 is classified as an O2III(f
*) star with a temperature of . The luminosity class of III indicates a star somewhat evolved and expanded compared to the
zero-age main sequence. The spectral peculiarity code (f
*) indicates strong N
III emission lines, even stronger NN
IV emission, and weak HeN
II emission. The star's radius is , but because of its high surface temperature it is two million times brighter than the Sun. The high temperature generates a fast
stellar wind
A stellar wind is a flow of gas ejected from the upper atmosphere of a star. It is distinguished from the bipolar outflows characteristic of young stars by being less collimated, although stellar winds are not generally spherically symmetric.
D ...
of ,
shedding over a millionth of the mass of the sun each year.
[ In 1995, HD 269810 was estimated to be 190 times the mass of the Sun][
]
Evolution
Stars as massive as HD 269810 with metallicity
In astronomy, metallicity is the abundance of elements present in an object that are heavier than hydrogen and helium. Most of the normal physical matter in the Universe is either hydrogen or helium, and astronomers use the word ''"metals"'' as a ...
typical of the Large Magellanic Cloud will maintain near-homogeneous chemical structure due to strong convection and rotational mixing. This produces strong helium and nitrogen surface abundance enhancement even during core hydrogen burning. Their rotation rates will also decrease significantly due to mass loss and envelope inflation, so that gamma-ray burst
In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies. They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten milli ...
s are unlikely when this type of star reaches core collapse. They are expected to develop directly into Wolf–Rayet star
Wolf–Rayet stars, often abbreviated as WR stars, are a rare heterogeneous set of stars with unusual spectra showing prominent broad emission lines of ionised helium and highly ionised nitrogen or carbon. The spectra indicate very high surface ...
s, passing through WN, WC, and WO stages before exploding as a type Ic supernova
A supernova is a powerful and luminous explosion of a star. It has the plural form supernovae or supernovas, and is abbreviated SN or SNe. This transient astronomical event occurs during the last evolutionary stages of a massive star or when ...
and leaving behind a black hole
A black hole is a region of spacetime where gravitation, gravity is so strong that nothing, including light or other Electromagnetic radiation, electromagnetic waves, has enough energy to escape it. The theory of general relativity predicts t ...
. The total lifetime would be around 2 million years, showing an O-type spectrum for most of that time before a shorter period with a WR spectrum.
References
External links
Heaviest Known Star Observed from Space
{{DEFAULTSORT:HD 269810
Stars in the Large Magellanic Cloud
Dorado (constellation)
Emission-line stars
269810
Large Magellanic Cloud
Extragalactic stars
O-type giants
J05351389-6733275