Bob Moler's Ephemeris Blog

Ephemeris for Thursday, October 1st.  The Sun will rise at 7:40.  It’ll be up for 11 hours and 43 minutes, setting at 7:23.   The Moon, 3 days before last quarter, will rise at 10:04 this evening.

Let’s look at the skies for the month of October.  The sun will still be moving south rapidly.  Daylight hours in the Interlochen/Traverse City area will drop from 11 hours and 43 minutes today to 10 hours 14 minutes on the 31st.  The altitude of the sun above the southern horizon at local noon will be 42 degrees tomorrow, and will descend to 31 degrees on Halloween, also in the Interlochen area.  The Straits area will have the sun a degree lower.  Local noon, when the sun is due south will be about 1:30 p.m. in Interlochen.  The planet Saturn will become harder to spot by the end of the month.  After that the evening sky will be devoid of bright planets for many months.  The outer planets Uranus and Neptune will be available for the telescope.

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

Addendum

Star Chart for October 2015. Created using my LookingUp program. Click on image to enlarge.

The planets and stars are plotted for the 15th at 8 p.m. EDT.  That is chart time.  Note, Traverse City is located 1 hour 45 minutes behind our time meridian.  To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.

Evening astronomical twilight ends at 9 p.m. EDT on October 1st, decreasing to 8:11 p.m. EDT on the 31st..

Morning astronomical twilight starts at 6:02 a.m. EDT on October 1st, and increasing to 6:40 a.m. EDT on the 31st.

Add a half hour to the chart time every week before the 15th and subtract and hour for every week after the 15th.

For a list of constellation names to go with the abbreviations click here.

The green pointer from the Big Dipper is:

• Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star.
• Follow the arc of the Big Dipper’s handle to Arcturus.
• The Summer Triangle is shown in red.

Calendar of Planetary Events

Credit:  Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC)

To generate your own calendar go to http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html

Times are Eastern Daylight Time on a 24 hour clock.  Some additions made to aid clarity.

Conjunctions like the Venus-Regulus: 2.5° S means Venus will appear 2.5° South of Regulus.