January 2010 Extra: While you wait

In this show we talk to Dr Stewart Eyres about Sakauri's Object. We put your astronomical questions to Tim, and round-up the feedback we've received. Apologies for the audio quality this time; one of our microphones has been playing up.

Sakurai's Object

When stars like the Sun begin to run out of nuclear fuel, they evolve into red giants and eventually throw off their outer layers forming planetary nebulae, some of the most beautiful objects in astrophysics. This exposes a white dwarf star, the extremely hot core of the star where the nuclear reactions had taken place. Sakurai's Object (V4334 Sgr) is an evolved star that, after ejecting its planetary nebula, suddenly re-brightened in 1996. Since then, Sakurai's Object has been studied in great detail as it is a rare chance for astronomers to watch an important phase of stellar evolution take place on short timescales.

Dr Stewart Eyres is an astrophysics researcher and Associate Head of School of Computing, Engineering and Physical Sciences at the University of Central Lancashire's Jeremiah Horrocks Institute. His research concentrates on the formation and development of circumstellar matter in binary and evolved stars, with a particular interest in the late stages of stellar evolution. He has worked on Sakurai's object, particularly using radio and infrared telescopes, since it first came to our attention back in 1996.

Ask an Astronomer

Tim answers your questions:

• Mary writes in to say "I was awake between 4am and 6am this morning when there were 4 enormous green flashes across the night sky. Hope you can inform me what this may have been."
• Robyn asks about whether the unprotected human body would freeze on exposure to space or to the Martian surface. Interesting article about exposure to space.
• Michael Mouat from Shetland asks "How do Jupiter?s satellites generate spots of aurorae at its poles?". Great picture of this on APOD.
• Sean asks about the route to becoming a professional astronomer. The Royal Astronomical Society have a good article about this (from a UK standpoint).
• John Murrell asks about spiral density waves and the analogy to a traffic jam that was discussed in Jodcast Live. He wonders what force would cause stars to slow down as they entered a density wave and accelerate away again on leaving as cars do in a traffic jam.

Odds and Ends

Stuart mentioned avalanches/landslides on Mars as seen by HiRISE.

Show Credits