WR 102ka
A luminous Wolf–Rayet star near the Galactic Center.
WR 102ka, also called the Peony Star, is a slash star located near the Galactic Center. It is one of several candidates for the most luminous-known star in the Milky Way. Its name, officially approved by the IAU Working Group on Star Names on 13 June 2026, refers to the surrounding Peony Nebula, which resembles a peony flower.
Quick Facts
- Common name
- Peony Star
- Star type
- Wolf–Rayet star (likely WN10)
- Location
- Near the Galactic Center
- Discovery year
- 2002–2003
- Iau name approval date
- 13 June 2026
Facts from the source article.
Discovery
WR 102ka lies near the Galactic Center and is essentially totally obscured in ultraviolet wavelengths, so it must be observed in longer wavelength infrared light that can penetrate the dust. It was catalogued in 2002 and 2003 by infrared surveys, including the Two-Micron All Sky Survey (2MASS) in the near-infrared J, H, and Ks bands and the ISOGAL survey of candidate young stellar objects at 7 μm and 15 μm. Narrowband infrared observations around 2 μm showed it was a Wolf–Rayet star with a likely classification of WN10, and it was also proposed as a possible luminous blue variable. The Spitzer Space Telescope observed it at 3.6 μm, 8 μm, and 24 μm on April 20, 2005, enabling the first reliable calculations of its physical properties.
Other luminous Milky Way stars
The closer star WR 25 may be more luminous than WR 102ka. Another nearer star, Eta Carinae, which was the second-brightest star in the sky for a few years in the 19th century, appears to be slightly more luminous than WR 102ka, but is known to be a binary star system. There is also the more recently discovered Pistol Star, which derives its name from the shape of the nebula in which it is embedded and which it has probably created through heavy mass loss via strong stellar winds and perhaps also mini-supernova-like eruptions as happened to Eta Carinae around the 1830s–1840s. The luminosities of the Pistol Star, Eta Carinae, and WR 102ka are all rendered somewhat uncertain due to heavy obscuration by galactic dust in the foreground. Both Eta Carinae and WR 102ka are believed likely to explode as supernovas or hypernovae within the next few million years, and both have expelled a considerable portion of their initial mass in dense, massive stellar winds.
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