Spotted surface structure of the active giant PZ Mon

Abstract

Based on our photometric observations in 2015-2016 and archival photometric data for the active red giant PZ Mon, we have found the main characteristics of the stellar surface: the unspotted surface temperature Teff=4730K, the spot temperature Tspot=3500K, and the relative spot area from 30 to 40%. The best agreement with the observations has been achieved in our three-spot model including a cool polar spot with a temperature of about 3500K as well as large and small warm spots with a temperature of about 4500K. The stable polar spot is responsible for the long-period brightness variations. Its presence is confirmed by an analysis of the TiO 7054$\mathring{A}$ molecular band. The small-amplitude 34-day variability is attributable to the warm spots located on the side of the secondary component, which determine the relatively stable active longitude.

arXiv comment8 pages, 7 figures, accept in Astromonical Letters, 2018

References in corpus (6)

• No Sun-like dynamo on the active star $\zeta$ Andromedae from starspot asymmetry
• Spherically-symmetric model stellar atmospheres and limb darkening I: limb-darkening laws, gravity-darkening coefficients and angular diameter corrections for red giant stars
• Doppler Images of the RS CVn Binary HR 1099 (V711 Tau) from the MUSICOS 1998 Campaign
• Ellipsoidal primary of the RS CVn binary zeta And: Investigation using high-resolution spectroscopy and optical interferometry
• Evolutionary status of the active star PZ Mon
• Sodium in the Atmospheres of Thick-Disk Red Giants

Cited by in corpus (1)

• Cool spots on the surface of the active giant PZ Mon