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07/31/2014 – Ephemeris – Previewing August skies

July 31, 2014 Comments off

Ephemeris for Thursday, July 31st.  The sun rises at 6:27.  It’ll be up for 14 hours and 41 minutes, setting at 9:09.   The moon, 3 days before first quarter, will set at 11:07 this evening.

Let’s look ahead at the month of August in the skies.  Daylight hours will decrease from 14 hours and 38 minutes tomorrow to 13 hours 16 minutes on the 31st.  The altitude of the sun at local noon, that is degrees of angle above the horizon will decrease from 63 degrees tomorrow to just over 53 degrees on the 31st.  Straits area listeners can subtract one more degree from those angles.  Local noon, when the sun is due south, is about 1:43 p.m.  The Perseid meteor shower will reach its peak on the morning of the 13th.  All but the brightest meteors will be lost in the bright moonlight.  Until then look for the meteors after the moon sets.  That radiant point, where the meteors will seem to come from, will be in the northeastern sky.

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

Addendum

August Star Chart

August star chart for 10 p.m. on August 15, 2014. Created by my LookingUp program.

The Moon is not plotted.  The planets are plotted for the 15th.  Mars will move eastward through the month and will approach Saturn.

Astronomical twilight ends at 11:11 p.m. on August 1st, decreasing to 10:05 on the 31st.

Add a half hour to 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.

Also shown is the Summer Triangle in red. Clockwise from the top star is Deneb in Cygnus, Vega in  Lyra and Altair in Aquila.

The yellow radiant marked PerR is the radiant for the Perseid meteor shower.

The green pointers from the Big Dipper are:

  • Pointer stars at the front of the bowl of the Big Dipper point to Polaris the North Star.
  • The arc of the dipper’s handle points to Arcturus.
  • The straighten the ark to a spike to point to Spica.
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