Archive
06/05/2018 – Ephemeris – Green flash
Ephemeris for Tuesday, June 5th. Today the Sun will be up for 15 hours and 25 minutes, setting at 9:24, and it will rise tomorrow at 5:58. The Moon, 1 day before last quarter, will rise at 2:16 tomorrow morning.
Now that it’s June and the season of summer is only two weeks away, thoughts run to heading out to the beach. One of the great pleasures of heading out to a Lake Michigan beach is seeing the sunset. And if the Sun sets on the cloudless horizon, a rare treat is to see the green flash. I’ve heard about it since my youth, but have seen it only once. I’ve seen the sunset many, though not a huge number of, times. The time I did, I was purposely looking for it. The green flash is when as the last part of the upper limb of the Sun disappears it suddenly turns green for a second, then it’s gone. So it’s easy to miss. The flash isn’t really brighter, but the top edge turns suddenly from reddish-orange to green as it disappears.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The green flash recorded by Brocken Inaglory in January 2006 from Santa Cruz, CA. GNU Free Documentation License from the Green Flash Wikipedia page, which has more examples.
06/04/2018 – Ephemeris – Ariadne’s crown
Ephemeris for Monday, June 4th. Today the Sun will be up for 15 hours and 24 minutes, setting at 9:23, and it will rise tomorrow at 5:58. The Moon, 2 days before last quarter, will rise at 1:47 tomorrow morning.
High in the southeast at 11 p.m. can be found a small but easily spotted constellation of Corona Borealis, the Northern Crown. It is located just east or left of the kite shaped constellation of Boötes, with its bright star Arcturus at the base. The Northern Crown is a semicircle of stars, like a tiara, with a brighter star Gemma at the bottom. Despite the obvious allusion of stars to diamonds and the sound of one of the star’s name, this is not a gem studded crown. Gemma means blossom, so Corona Borealis may represent a floral crown. According to Greek mythology it belonged to Princess Ariadne, daughter of King Minos of Crete. She was abandoned by Theseus, whom she helped out of the Labyrinth of the Minotaur.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Animated Corona Borealis Finder Chart looking to the southeast at 10:30 p.m. June 4, 2018. Corona Borealis is a small constellation, so I added its neighbors for context. Click on the image to enlarge. Created using Stellarium and GIMP.
06/01/2018 – Ephemeris – Presentation tonight: Cosmic rays and the quiet Sun
Ephemeris for Friday, June 1st. Today the Sun will be up for 15 hours and 21 minutes, setting at 9:21, and it will rise tomorrow at 5:59. The Moon, 3 days past full, will rise at 11:57 this evening.
Tonight at 8 p.m. at the June meeting of the Grand Traverse Astronomical Society at Northwestern Michigan College’s Rogers Observatory, Observatory Director Jerry Dobek will be giving a talk on how the Earth is receiving more cosmic rays from outside the solar system now that the Sun is in its quiet phase. Cosmic rays are not like x-rays or other forms of electromagnetic radiation. They are particles, bare nuclei of atoms, some pretty heavy. They are a danger to airline crews who fly over the north pole daily. After the meeting, at 9 p.m. the society will host a star party to view the planets Venus and Jupiter. The observatory is located south of Traverse City on Birmley Road between Garfield and Keystone roads.
43rd Anniversary of Ephemeris!
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Bob Moler's Ephemeris Blog 