Severo Ochoa Seminar by prof. K. Rao

The Severo Ochoa visitor Dr. Kameswara Rao Neelamraju will give a Severo Ochoa Seminar at the IAC on 2014 April 1st entitled R Coronae Borealis stars and their dust.

Start date: 1 Apr, 2014 - 12:30
End date: 1 Apr, 2014 - 14:00
Location: Aula, IAC Headquarters, Tenerife.
Organizer: Instituto de Astrofísica de Canarias

Abstract:

R Coronae Borealis (RCB) stars are the more prominent group of high luminosity hydrogen deficient stars that are rich in carbon and helium. They also show characteristic irregular light drops of several magnitudes (between 3 and 8 magnitudes) at unpredictable times, caused by expulsion of self-made clouds of dust. They range in surface temperatures from 4500 K to 20000 K. Some of them seem to have made even such complex molecules like fullerenes (C60) in their circumstellar regions. Neither their evolutionary history nor the dust formation mechanism are well understood. Two scenarios that have been suggested are that the present stars are a result of merger of two white dwarfs (CO+He) or a post born-again (AGB) giant that is surviving after a final helium shell flash. The talk would describe the RCB properties and highlight the problems and challenges they pose in understanding their origins and dust production.

Currently Dr. Rao is senior professor at the Indian Institute of Astrophysics in Bangalore (India).