Highland Road Park Observatory

THE EDGE OF NIGHT
(Winter Session)

Friday 8 March from 5:30 pm to 7:30 pm CST
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!

  • 5:45 pm to 6:45 pm = Moon viewing
  • 6:08pm = “civil twilight” begins (search for crepuscular rays)
  • 6:30 pm to 6:38 pm = magnitude 1.9 pass of a Chang-Zheng 4B rocket
  • 6:33 pm = “civil twilight” ends; “nautical twilight” begins
  • 6:44 pm to 6:54 pm = magnitude 2.0 pass of Lacrosse 5
  • 6:46 pm to 6:55 pm = magnitude 1.9 pass of the Lacrosse 4 rocket
  • 6:53 pm = magnitude -1.1 flare of Iridium 54
  • 7:01 pm = “nautical twilight” ends; “astronomical twilight” begins
  • 7:07 pm to 7:11 pm = magnitude 2.3 pass of the Earth Radiation Budget Satellite
  • 7:28 pm = “astronomical twilight” ends

{The various twilights will be explained.}

Celestial Objects in Order of Appearance (with magnitudes):

Waxing Crescent Moon [-9.4] / Sirius [-1.5] / Canopus [-0.7] / Capella [0.1] / Rigel [0.1] / Procyon [0.3] / Betelgeuse [0.5] / Aldebaran [0.8] / Pollux [1.1] / Pleiades Star Cluster [1.2] / Regulus [1.3] / Adhara [1.5] / Castor [1.6] / Polaris [2.0]

NOTE: The 5 April lecture “Wonders of the Spring 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, February 8, 2019, 05:38 PM.