[net.astro] StarDate: May 27 The Moon and Regulus

dipper@utastro.UUCP (Debbie Byrd) (05/27/85)

The moon is in the constellation Leo tonight.  More on moonlight and
starlight -- after this.

May 27  The Moon and Regulus

That bright object near the first-quarter moon tonight is Regulus --
the brightest star in the constellation Leo the Lion.  Regulus is the
star at the bottom of the backwards question mark pattern that
represents the head of the lion.

Ancient skywatchers would have said that the moon tonight is "in" Leo.
That simply means that -- from our vantagepoint on Earth -- the moon
appears against the pattern of stars that makes up the constellation
Leo.  When we look at the moon tonight -- we're also looking towards
the same general direction of these stars in space.

The stars of Leo are far in the background indeed -- while the moon is
near the Earth, relatively speaking.  Regulus -- the star at the bottom
of the backwards question mark -- lies about 85 light years away from
us.  The light you see from Regulus tonight traveled through space for
85 years -- at 186 thousand miles a second -- before reaching the Earth
-- and your eyes.  The star at the other end of the question mark --
the curved end -- is called Epsilon Leonis.  It's located 340 light
years away.  Right above Regulus in the question mark pattern is a
third star -- Eta Leonis -- whose light traveled through space for two
thousand years before arriving in our vicinity.

The moon, meanwhile, is much closer.  The moonlight you see takes a
double journey -- first from the sun to the moon -- which took about
eight minutes.  Reflected from the moon's surface -- the light then
took less than two seconds before reaching your eyes.


Script by Diana Hadley.


(c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin