Highland Road Park Observatory

THE EDGE OF NIGHT
(Summer Session)

Friday 6 July from 8:00 pm to 10:00 pm CDT
No admission fee. For all ages.
Binoculars strongly encouraged.

It’s not light, it’s not dark. It’s that special time called twilight, and HRPO wants to introduce you to it!

*Are all sections of the sky the same shade of blue?
*Which stars are seen first?
*Are Mercury☿ and Venus♀ or the Moon out?
*Is that moving object a plane, a satellite or space debris?
*How much actual darkness should I expect in a light-polluted city when twilight has passed?

There is no other time like twilight. Bring it into your life!

  • 8:00 pm to 9:00 pm = Mercury☿ viewing
  • 8:00 pm to 9:45 pm = Venus♀ viewing
  • 8:10 pm = “civil twilight” begins (search for crepuscular rays)
  • 8:38 pm = “civil twilight” ends; “nautical twilight” begins
  • 8:42 pm to 8:48 pm = magnitude 1.3 pass of USA 186
  • 9:00 pm to 10:00 pm = Jupiter♃ viewing
  • 9:02 pm to 9:08 pm = magnitude 2.0 pass of the Shenzhou-11 Module
  • 9:12 pm = “nautical twilight” ends; “astronomical twilight” begins
  • 9:16 pm = magnitude -6.1 flare of Iridium #81
  • 9:30 pm to 10:00 pm = Saturn♄ viewing
  • 9:47 pm = “astronomical twilight” ends

{The various twilights will be explained.}

Celestial Objects in Order of Appearance (with magnitudes):

Venus♀ [-4.1] / Jupiter♃ [-2.3] / Arcturus [-0.05] / Vega [0.0] / Saturn♄ [0.1] / Mercury☿ [0.3] / Altair [0.7] / Aldebaran [0.8] / Spica [0.9] / Antares [1.0] / Regulus [1.3] / Polaris [2.0]

NOTE: The 13 July lecture “Wonders of the Summer Sky” is an excellent followup to this session.

This program pre-empts the Friday Night Lecture Series on…
*the last Friday in spring before Daylight Time begins
*the Friday during the week of Independence Day
*the first Friday in fall after Daylight Time ends

HRPO 2015 09 15 1901

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Updated by Frederick J. Barnett on Friday, June 15, 2018, 04:57 PM.