WR 102ka (Peony Nebula star) — a very luminous massive star near the Galactic Center

Physical characteristics

Estimates place the star's radius at roughly ninety times that of the Sun and its bolometric luminosity at several million times solar output — published values often cite about 3.2 million L☉, though measurements vary with assumptions about extinction and distance (luminosity estimates). Spectroscopically it shows strong emission features and dense, fast winds; some authors treat it as a Wolf–Rayet object while others consider it a luminous blue variable candidate because of its extreme luminosity and circumstellar material.

Discovery and local environment

WR 102ka was identified through infrared surveys that penetrate the dense dust toward the Galactic Centre. It is embedded in a dusty emission nebula nicknamed the Peony Nebula; that nebulosity is likely formed by material lost from the star through powerful winds or past eruptive episodes. The combination of dust and gas around the star makes direct optical study difficult.

Evolution, fate and importance

As a very massive, evolved object, WR 102ka is in a late stage of stellar evolution. Continuous mass loss will shape its later evolution; its ultimate end is expected to be a core-collapse supernova or direct collapse to a black hole, depending on remaining mass and rotation. Astronomers study WR 102ka to learn about mass loss, feedback into the interstellar medium, and the lives of the most massive stars in environments like the Galactic Centre.

• Location: Sagittarius, near the Galactic Centre.
• Radius: roughly 90–100 R☉ (order of magnitude).
• Luminosity: on the order of a few million L☉ (published estimates vary).
• Type: emission-line star; Wolf–Rayet / luminous blue variable candidate.