PTF10fqs: A Luminous Red Nova in the Spiral Galaxy Messier 99

Understand

The Palomar Transient Factory (PTF) is systematically charting the optical transient and variable sky.

• A primary science driver of PTF is building a complete inventory of transients in the local Universe (distance less than 200 Mpc).
• Here, we report the discovery of PTF10fqs, a transient in the luminosity "gap" between novae and supernovae.
• Located on a spiral arm of Messier 99, PTF 10fqs has a peak luminosity of Mr = -12.3, red color (g-r = 1.0) and is slowly evolving (decayed by 1 mag in 68 days).