Bob Moler's Ephemeris Blog

Ephemeris for Tuesday, January 15th.  The sun will rise at 8:15.  It’ll be up for 9 hours and 13 minutes, setting at 5:28.   The moon, 3 days before first quarter, will set at 10:31 this evening.

The bright red star in constellation Orion’s shoulder is Betelgeuse, 643 light years away give or take 146 light years.  Betelgeuse is a shortened form of an Arabic phrase that means “Armpit of the central one”.  Orion is seen in the south in the evening.  Even at its great distance it’s the star whose surface is easiest seen, after the sun of course.  That’s because it’s so big.  As somewhat larger around than the orbit of Jupiter, it turns out.  Recent telescopic observations of Betelgeuse have shown plumes of gas surrounding the star.  A star like Betelgeuse is so bloated that it can be described as a red hot vacuum, thus its edge or limb is much darker than its center.  The sun has limb darkening too, but it is much less noticeable.

Tonight:

STEM (Science, Technology, Engineering, Mathematics) Night.

We’ll have Gary Carlisle and I will be there to view the moon and Jupiter if it’s clear, Make craters hands-on.  I’ll be helping to make comets.  Bring your gloves because comets are COLD!  We’ll be representing the Grand Traverse Astronomical Society.

Times above are for the Traverse City/Interlochen area of Michigan.  They may be different for your location.

Addendum

Orion facing Taurus letting Lepus escape with Jupiter in 2013. Check out Betelgeuse.  Created using Stellarium.

Betelgeuse and its nebula. From the European Southern Observatory’s Very Large Telescope.