WR 102ka

~ 3,200,000 L ☉

WR 102ka, and peony mist star called, is a very massive star of 10-50 solar masses in the constellation Sagittarius. It is a blue hyper giant which belongs to the class of Wolf -Rayet stars. He is one of the most luminous stars in the Milky Way.

The approximately 26,000 light- years distant star was discovered using the Spitzer Space Telescope near the center of our galaxy. It received its name from the eponymous surrounding mist, whose appearance is reminiscent of the flowers of peonies.

Physical Properties

WR 102ka is not observable in the visible light. Only observations in the infrared spectral range by Spitzer made ​​him visible.

Using the 3.6-meter New Technology Telescope ( NTT ) of the European Southern Observatory ( ESO) in Chile was the brightness of WR 102ka be specified. Measurements indicate that he reached the 3.2 million times the luminosity of our Sun, the absolute luminosity is very difficult to determine, so it is quite possible that he has a similarly high luminosity as Eta Carinae.

WR 102ka belongs to the spectral class WN outside the standard sequences and the WN - type Wolf -Rayet stars, which mainly shows emission lines of nitrogen.


In the most luminous stars are at the same time the most massive. Researchers assume that the Peony nebula star began its existence as a luminous Strong Blue Variable ( LBV) with 150-200 solar masses. Such extremely massive stars are extremely rare and represent the researchers until now remained a mystery since their mass is actually higher than the maximum limit for a single star (see Eddington limit as a theoretical upper limit of the stellar mass, and Humphreys -Davidson limit). Beyond this limit generates a star so much radiation that it can not hold together longer its matter, since the externally active radiation pressure overcomes the force of gravity acting inward, and so repels its outer layers. The star would break apart in double or multiple stars.

Today he is one of the Wolf -Rayet stars, and still has a mass of 10-50 solar masses on. He has about 100 times the diameter of our central star. WR stars are characterized in that they repel large amounts of matter in their environment, resulting in a significant loss of mass. These stellar winds are accelerated by the radiation from the star and reach speeds of up to 1.6 million kilometers per hour, with millions of years until he can lose some solar masses within ten thousands.

Astronomers are confident that WR 102ka is named after its only a few million years of life, explode in a supernova, probably from the type Ic SN. He will for some time brighter than all other stars of the Milky Way together, what will be unobservable from the earth, however, there is almost absorb its surrounding dust and mist all the light from the explosion.