Archive for binary star

An Astronomical Teaser

Posted in Cute Problems, The Universe and Stuff with tags , , , , on January 1, 2014 by telescoper

For those of you who feel up to a little brain-teaser after last night’s revels, try this little problem which involves the use of everybody’s favourite type of astronomical measurement, the magnitude system. Answers through the comment box please!

A binary star at a distance of 100 pc has such a small separation between its component stars that it is unresolved by a telescope. If the apparent visual magnitude of the combined image of the system is 10.5, and one star is known to have an absolute visual magnitude of 9.0, what is the absolute visual magnitude of the other star?