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02/20/2020 – Ephemeris – The Winter Triangle

February 20, 2020 Comments off

Ephemeris for Thursday, February 20th. Today the Sun will be up for 10 hours and 41 minutes, setting at 6:17, and it will rise tomorrow at 7:34. The Moon, 3 days before new, will rise at 6:53 tomorrow morning.

I usually talk about the Winter Circle of bright stars, but some other astronomers talk about the Winter Triangle. The stars involved are Betelgeuse in the hunter Orion, Sirius in Canis Major, Orion’s large hunting dog, and Procyon in Canis Minor, his other small hunting dog. These three stars enclose a rather blank piece of sky with the faint Milky Way running through it and the equally invisible constellation of Monoceros the unicorn. The Summer Triangle has three bright stars with no other close competition. The Winter Triangle has 4 other bright stars near it. Any three of these would make a nice triangle. One of these stars, Betelgeuse has been the news recently because it is dimming to an unprecedented degree.

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

Addendum

Winter Triangle

The Winter Triangle. It enclose a pretty blank space where Monoceros the unicorn lies. Created using Stellarium with my annotations for the Winter Triangle. By the way, Betelgeuse is currently only as bright as Bellatrix, the star next to the “n” in Orion.

01/03/2020 – Ephemeris – Astronomical events this weekend

January 3, 2020 Comments off

Ephemeris for Friday, January 3rd. The Sun will rise at 8:20. It’ll be up for 8 hours and 54 minutes, setting at 5:14. The Moon, 1 day past first quarter, will set at 1:49 tomorrow morning.

Tonight at 8 p.m. there will be a telescope clinic by the Grand Traverse Astronomical Society at the Rogers Observatory south of Traverse City on Birmley Road for those who have either received a telescope for Christmas or have one hidden away in an attic, to learn how to use it. Bring ‘em if you’ve got ‘em.

Tomorrow morning we’ll see the peak of the Quadrantid meteor shower after the Moon sets. The radiant for this shower is near the handle of the Big Dipper, though they will be seen all over the sky. The peak should be around 3:20 a.m. with the possibility of over a hundred meteors visible per hour.

On Sunday at 5 a.m. the Earth will be its closest to the Sun for the year of 91,394,000 miles (147,085,000 km).

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

Addendum

Quadrantid radiant

The location of the Quadrantid radiant at 3:20 a.m. January 4, 2020 for the peak of the meteor shower. Created using Stellarium.

Earth's orbit

The Earth’s orbit, somewhat exaggerated, showing perihelion and the seasons. Credit “Starts with a Bang” blog by Ethan Siegel.

12/03/2019 – Ephemeris – The Moon tonight

December 3, 2019 Comments off

Ephemeris for Tuesday, December 3rd. Today the Sun will be up for 9 hours and 1 minute, setting at 5:03, and it will rise tomorrow at 8:02. The Moon, 1 day before first quarter, will set at midnight.

The Moon tonight is a few hours before being at first quarter, when the Moon appears exactly half illuminated. In viewing the Moon with a pair of binoculars or a telescope the observer will notice that the best detail is seen near the terminator, the sunrise line, that’s cutting the Moon in half. That’s where the shadows are longest. The large gray feature at the upper right of the Moon is Mare Serenitatis, which translates to the Sea of Serenity. To me it appears to look like a scallop shell. Serenitatis like most other seas is roughly circular and is actually a crater, the result of an impact of a large asteroid during what is called the late heavy bombardment that happened about 4 billion years ago.

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

Addendum

Binocular Moon

The moon as will appear tonight at 8 p.m. December 3, 2019 EST. Moon image credit NASA Scientific Visualization Studio.

Images of the moon’s phase for the entire year are available from https://svs.gsfc.nasa.gov/4442.

Scallop shell

Image of a scallop shell rotated to match the Sea of Serenity. Credit Wikipedia user Kevmin. (Creative Commons)

11/28/2019 – Ephemeris – This is the best time to spot Mercury in the morning

November 28, 2019 Comments off

Ephemeris for Thanksgiving Day, Thursday, November 28th. Today the Sun will be up for 9 hours and 8 minutes, setting at 5:05, and it will rise tomorrow at 7:57. The Moon, 2 days past new, will set at 6:59 this evening.

The planet Mercury is at its greatest western elongation from the Sun this morning. Being west of the Sun it rises first. It being a planet inside the Earth’s orbit it appears to swing from the east side to the west side of the Sun, from the evening to the morning side of the Sun. It never appears outside of twilight around here. For the next week it will be going away from us, and becoming more illuminated by the Sun from our perspective, and actually is getting brighter. Then it will seem to fall back, actually moving around and behind the Sun. This evening the thin sliver of the Moon will appear near brilliant Venus. The best time to look is around an hour after sunset, which is about 6 p.m. Venus will set at 6:43 p.m.

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

Addendum

Mercury for the next week

Mercury in the morning, about an hour before sunrise (7 a.m. here) for the next week. The aspect of its orbit changes for two reasons, sunrise time is advancing a bit, and the Earth is changing its position with respect to Mercury and its orbit, and Mercury too is moving. Create using Stellarium and GIMP.

11/11/2019 – Ephemeris – Mercury is passing across the face of the Sun today

November 11, 2019 Comments off

Ephemeris for Veteran’s Day, Monday, November 11th. Today the Sun will be up for 9 hours and 45 minutes, setting at 5:19, and it will rise tomorrow at 7:35. The Moon, 1 day before full, will set at 7:24 tomorrow morning.

Today we are bring treated by a rare event. The planet Mercury is crossing the face of the Sun. It’s called the transit of Mercury. The last one visible from around here was 3 ½ years ago, and the next one will be visible here in 2049. The transit starts at sunrise when Mercury starts to cross the Sun from the lower left from sunrise and will cross the Sun until 1:04 p.m. where it will leave the Sun at the upper right. The best way to see it will be to project the Sun’s image on a white card using binoculars or a telescope. Do not look through them at the Sun. Solar eclipse glasses will not work because Mercury is too small. Do not use eclipse glasses with binoculars. The Sun’s heat will melt the filters and cause blindness.

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

Addendum

One or more members of the Grand Traverse Astronomical Society mayl be out in the parking lot of Mari Vineyards 8175 Center Road on Old Mission Peninsula, but only if it’s clear. Be advised that there is a winter storm warning for the Grand Traverse Area from 1 a.m. to 6 p.m. today.  That means that chances are slim that we’ll have a big enough clear spot to observe through.  But I’ll be on the look out., and am a half an hour away.

I found a source for streaming video fo the transit from Griffith Observatory in Los Angeles:  https://www.youtube.com/watch?v=rYZKNhTJmOI.

Being on the west coast they will miss part of the transit.  They’ll go live at 9:15 a.m. our time.  Sunrise over there is at 9:22 our time.  There’s more information on: http://www.griffithobservatory.org/events/Transit_of_Mercury_2019.html.

More information about viewing the transit is on: https://spaceweather.com/

Path of Mercury across the Sun

Path of Mercury across the Sun. The planet will move from lower left to upper right. The passage will be from lower left to upper right. Credit: Occult 4.

Binocular projection

I’m demonstrating using binoculars to project the Sun. Photo by Bea Farrell (granddaughter).

Mercury Inferior Conj.  (Transit) 
Transit of Mercury on 2019 Nov 11 (TT)
     Geocentric Event      UTC          EST          P.A.
                           h  m  s                      o 
[1]  Exterior Ingress      12 35 27    7:35.27 a.m.  110.0
[2]  Minimum Separation    15 19 48   10:19:48 a.m.
[3]  Exterior Egress       18  4 14    1:04:14 a.m.  298.6

Minimum sepn 75.9";  Radii - Sun 969.3", Mercury 5.0"
delta T =  70.2 secs,  Ephemeris = DE0
Transit Map

The Sun facing side of the Earth at the start and end of the transit. If you can see your location on either of these maps the transit or part of it will be visible from your location. Credit Occult 4.

11/08/2019 – Ephemeris – On Monday tiny Mercury will cross the face of the Sun

November 8, 2019 Comments off

Ephemeris for Friday, November 8th. Today the Sun will be up for 9 hours and 52 minutes, setting at 5:22, and it will rise tomorrow at 7:31. The Moon, half way from first quarter to full, will set at 4:14 tomorrow morning.

Monday we will be treated by a rare event. The planet Mercury will cross the face of the Sun. It’s called the transit of Mercury. The last one visible from around here was 3 ½ years ago, and the next one will be in 2049. Mercury will start across the Sun from the lower left from sunrise at 7:35 and will cross the Sun until 1:04 p.m. where it will leave the Sun at the upper right. The best way to see it will be to project the Sun’s image on a white card using binoculars or a telescope. Do not look through them at the Sun. Solar eclipse glasses will not work because Mercury is too small. Do not use eclipse glasses with binoculars. The heat will melt the glasses and cause blindness. I’ll have more information Monday.

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

Addendum

Path of Mercury across the Sun

Path of Mercury across the Sun. The planet will move from lower left to upper right. The passage will be from lower left to upper right. Credit: Occult 4.

Binocular projection

I’m demonstrating using binoculars to project the Sun. Photo by Bea Farrell (granddaughter).

Mercury Inferior Conj.  (Transit) 
Transit of Mercury on 2019 Nov 11 (TT)
     Geocentric Event      UTC          EST          P.A.
                           h  m  s                      o 
[1]  Exterior Ingress      12 35 27    7:35.27 a.m.  110.0
[2]  Minimum Separation    15 19 48   10:19:48 a.m.
[3]  Exterior Egress       18  4 14    1:04:14 a.m.  298.6

Minimum sepn 75.9";  Radii - Sun 969.3", Mercury 5.0"
delta T =  70.2 secs,  Ephemeris = DE0

10/03/2019 -Ephemeris – The Moon tonight

October 3, 2019 Comments off

Ephemeris for Thursday, October 3rd. Today the Sun will be up for 11 hours and 37 minutes, setting at 7:20, and it will rise tomorrow at 7:44. The Moon, 2 days before first quarter, will set at 10:46 this evening.

The planet Jupiter will appear below and right of the crescent Moon tonight. This evening one of the striking lunar craters will be seen at the sunrise line or terminator on the Moon. The crater might just be glimpsed in steadily held or tripod mounted binoculars, and definitely in a small telescope. The crater is Theophilus, some 61 miles (101 km) in diameter located south of the Sea of Tranquility. At lunar sunrise the central peak of the crater catches the Sun of the lunar sunrise way before the floor is illuminated showing a point of light within the circular crater rim against the black floor of the crater. That should happen before the Moon sets at quarter to 11 p.m. The central peak extends 650 feet (200 m) above the crater walls.

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

Addendum

The Moon

The Crater Theophilus on the Moon’s terminator at10 p.m. October 3, 2019, Created using Virtual Moon Atlas.