Ephemeris: 08/13/2024 – Antares and the Moon
This is Ephemeris for Tuesday, August 13th. Today the Sun will be up for 14 hours and 7 minutes, setting at 8:50, and it will rise tomorrow at 6:44. The Moon, 1 day past first quarter, will set at 12:41 tomorrow morning.
The Moon tonight will have a companion. Just to the left of it will be a star. That star may not look very bright because it is overpowered by moonlight, but it is one of the brightest stars of the sky. It is Antares in Scorpius the scorpion, a red giant star. Every month for the last several years and for the next several years the moon will pass in front of that star. Unfortunately due to the timing and to the path of the Moon it doesn’t happen for any particular spot on the Earth very often. Tonight, as the Moon sets it will be approaching Antares but will appear about to pass below it at the time it sets. We will not be able to see the Moon actually cover or occult Antares from Northern Michigan until May 2028, nearly four years from now.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum

Ephemeris: 08/12/2024 – Expect a stellar explosion soon
This is Ephemeris for Monday, August 12th. Today the Sun will be up for 14 hours and 9 minutes, setting at 8:52, and it will rise tomorrow at 6:43. The Moon, at first quarter today, will set at 12:07 tomorrow morning.
This is a reminder that we are expecting a once in a lifetime nova or exploding star in our skies fairly soon, maybe in a month or two. At least we’re hoping. Unlike many reoccurring events in astronomy this one cannot be predicted exactly since we’re not really sure what is happening. We have a general idea. The star is T Coronae Borealis which is in the Northern Crown constellation, which is a small semicircular stellar group near the star Arcturus which is a bright star found off the end of the handle of the Big Dipper. It is to the upper left of that star and the kite shaped constellation of Boötes of which Arcturus is at the base. The nova will appear as bright as Corona’s brightest star, but will fade in about 8 days below naked eye visibility. So it will be easy to miss.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum

Ephemeris: 08/09/2024 – Star Party tomorrow night!
This is Ephemeris for Friday, August 9th. Today the Sun will be up for 14 hours and 17 minutes, setting at 8:56, and it will rise tomorrow at 6:40. The Moon, 3 days before first quarter, will set at 11:03 this evening.
Tomorrow The Grand Traverse Astronomical Society will be part of the Port Oneida Rural Arts and Culture Fair, an event sponsored by the Sleeping Bear Dunes National Lakeshore. The society will bring their telescopes to the Thoreson Farm on South Thoreson Road off M22 North of Glen Arbor for a Star Party beginning at 9 p.m. South Thoreson Road is a loop off M22. On tap will be the fat waxing crescent Moon and some of the brighter wonders of the summer sky. Even though the moonlit skies will be bright, there are plenty of wonders still visible in the telescopes. We might have a shot at Saturn later in the evening along with a few bright Perseid meteors to wow the viewer. The peak of the Perseid meteor shower will be Monday morning after the Moon sets.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum

Ephemeris: 08/08/2024 – The source of the Perseid Meteor Shower
This is Ephemeris for Thursday, August 8th. Today the Sun will be up for 14 hours and 20 minutes, setting at 8:58, and it will rise tomorrow at 6:38. The Moon, halfway from new to first quarter, will set at 10:47 this evening.
The source of the Perseid meteor shower is Comet Swift-Tuttle, first discovered in 1862 buy Lewis Swift and Horace Parnell Tuttle. The comet was expected back around 1982, but it didn’t show. Its orbit was recalculated and was expected around 1992, when it indeed showed up. The comet has a 130 or so year orbit of the Sun which does vary from appearance to appearance. The comet appears to be in resonance with Jupiter’s orbit of the Sun, going around once in the same time Jupiter goes around the Sun 11 times. Its next appearance in the inner solar system will be in the year 2126, when it is expected to be quite bright then, coming relatively close to the Earth.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum

Ephemeris: 08/07/2024 – Where have the naked eye planets wandered off to?
This is Ephemeris for Wednesday, August 7th. Today the Sun will be up for 14 hours and 23 minutes, setting at 8:59, and it will rise tomorrow at 6:37. The Moon, 3 days past new, will set at 10:31 this evening.
Let’s take our weekly look at the whereabouts of the naked-eye planets. The Moon will be visible as a thin crescent in the west with Venus lower in the west northwest around 9:30 pm. It will set at 9:56 pm in the west-northwest. Venus is best seen over a very low or lake horizon. Saturn will rise at 10:17 pm, and by 11 pm will be low in the east southeast, pretty much by itself. Saturn may look disappointing in telescopes this year since rings are nearly edge on and appear almost as a line through the planet. The other two visible planets are in the morning sky.
By 5:30 tomorrow morning, or an hour before sunrise, Jupiter and Mars will be up in the east, with Mars approaching Jupiter just above and to the right of it. Mars will rise at 1:41 am, and Jupiter at 1:53 am.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum







Ephemeris: 08/06/2024 – Looking toward the Perseid Meteor Shower
This is Ephemeris for Tuesday, August 6th. Today the Sun will be up for 14 hours and 25 minutes, setting at 9:01, and it will rise tomorrow at 6:36. The Moon, 2 days past new, will set at 10:15 this evening.
Next Monday morning we’ll see the peak of the Perseid meteor shower. They’re called the Perseids because they seem to come from the constellation of Perseus the hero which is below the W shaped constellation of Cassiopeia in the northeast in the evenings now. The reason they appear to come from the same direction is that they were shed by a comet whose name is Swift-Tuttle discovered in 1862 it’s been around many times before that, though not recognized as such. The first mention of the Perseids in history comes from the year 36 CE, though they were assuredly visible but unrecognized before that. In the past they’ve been known as the Tears of Saint Lawrence because their peak is near the feast date of that martyr. Perseids can be seen now, though not in peak numbers.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum

Ephemeris: 08/05/2024 – Finding Aquila the Eagle
This is Ephemeris for Monday, August 5th. Today the Sun will be up for 14 hours and 28 minutes, setting at 9:02, and it will rise tomorrow at 6:35. The Moon, 1 day past new, will set at 9:58 this evening.
The bright star Altair is seen halfway up the sky in the southeast at 10:30 this evening. It is one of the stars of the Summer Triangle with Vega above it, and Deneb above and left of it. It is the brightest star in the constellation Aquila the eagle which is seen flying northward through the Milky Way, with Altair at its head. Altair is flanked by two stars one above one below. Its wing tips can be seen below, and to the upper right. His tail is almost lost in the Milky Way seen lower in the east southeast. Here in Aquila is where the great rift, the dark band that splits the Milky Way, is most prominent. The Greeks and Romans seemed to have trouble telling vultures and eagles apart. Another name of the constellation was Vultur Volans.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). They will be different for other locations.
Addendum
Ephemeris: 08/02/2024 – The Northern Cross
This is Ephemeris for Friday, August 2nd. Today the Sun will be up for 14 hours and 35 minutes, setting at 9:06, and it will rise tomorrow at 6:31. The Moon, 2 days before new, will rise at 5:12 tomorrow morning.
The star Deneb is high in the east-northeast. It is the dimmest of the three stars of the Summer Triangle. It is at the head of the Northern Cross, an informal constellation or asterism. The upright extends to the South. The crossbeam can be seen crossing the star just south of Deneb. There’s also a constellation there. It’s actually Cygnus the swan flying southward along the Milky Way with its neck outstretched. The Anishinaabe natives peoples of our area see Ajijaak the crane, also with a long neck flying north, but also long legs trailing to the south, its wings outstretched. In Greek mythology Cygnus was the guise of the god Zeus when he seduced Leda, whose offspring was Pollux, one of the Gemini twins.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). They may be different for your location.
Addendum

Ephemeris: 08/01/2024 – Previewing August skies
This is Ephemeris for Thursday, August 1st. Today the Sun will be up for 14 hours and 38 minutes, setting at 9:07, and it will rise tomorrow at 6:30. The Moon, 3 days before new, will rise at 4:03 tomorrow morning.
Let’s look ahead at the month of August in the skies. Daylight hours will decrease from 14 hours and 38 minutes today to 13 hours 15 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 today 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 big event of the month will be in the morning sky: The Perseid meteor shower will be best seen on the morning of the 12th after the Moon sets, though members of the shower can be seen now. August is the first of my two favorite months for viewing the wonders of the summer Milky Way.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). They may be different for your location.
Addendum
August Evening Star Chart

The planets and stars are plotted for the 15th at 10 pm EDT in the evening and 5 am. These are the chart times. Note that Traverse City is located approximately 45 minutes behind our time meridian, West 75° longitude. (An hour 45 minutes behind our daylight saving time meridian during EDT). To duplicate the star positions on a planisphere you may have to set it to 1 hour 45 minutes earlier than the current time.
Note the chart times are for the 15th. For each week before the 15th, add ½ hour (28 minutes if you’re picky). For each week after the 15th, subtract ½ hour. The planet positions are updated each Wednesday on this blog. See them for planet positions on dates other than the 15th.
August Morning Star Chart

For a list of constellation names to go with the abbreviations, click here.
- Pointer stars at the front of the bowl of the Big Dipper point to Polaris, the North Star.
- Leaky dipper drips on Leo.
- Follow the arc of the handle of the Big Dipper to the star Arcturus, and
- Extend like a spike to Spica.
- The Summer Triangle is in red.
- PerR is the radiant of the Perseid meteor shower (Peaks on the morning of the 12th)
Twilight Limits, Nautical and Astronomical
| EDT | |||||||
| Morning | Twilight | Evening | Twilight | Dark | Night | Moon | |
| Date | Astro. | Nautical | Nautical | Astro. | Start | End | Illum. |
| 2024-08-01 | 4h28m | 5h16m | 22h26m | 23h14m | 23h14m | 3h01m | 0.05 |
| 2024-08-02 | 4h30m | 5h17m | 22h24m | 23h12m | 23h12m | 4h04m | 0.02 |
| 2024-08-03 | 4h32m | 5h19m | 22h23m | 23h10m | 23h10m | 4h32m | 0.00 |
| 2024-08-04 | 4h34m | 5h20m | 22h21m | 23h08m | 23h08m | 4h34m | 0.01 |
| 2024-08-05 | 4h35m | 5h22m | 22h19m | 23h06m | 23h06m | 4h35m | 0.03 |
| 2024-08-06 | 4h37m | 5h23m | 22h18m | 23h04m | 23h04m | 4h37m | 0.07 |
| 2024-08-07 | 4h39m | 5h25m | 22h16m | 23h01m | 23h01m | 4h39m | 0.13 |
| 2024-08-08 | 4h41m | 5h26m | 22h14m | 22h59m | 22h59m | 4h41m | 0.20 |
| 2024-08-09 | 4h43m | 5h28m | 22h12m | 22h57m | 23h03m | 4h43m | 0.28 |
| 2024-08-10 | 4h45m | 5h29m | 22h10m | 22h55m | 23h21m | 4h45m | 0.36 |
| 2024-08-11 | 4h47m | 5h31m | 22h09m | 22h53m | 23h42m | 4h47m | 0.46 |
| 2024-08-12 | 4h49m | 5h32m | 22h07m | 22h51m | – | 4h49m | 0.56 |
| 2024-08-13 | 4h50m | 5h34m | 22h05m | 22h48m | 0h08m | 4h50m | 0.66 |
| 2024-08-14 | 4h52m | 5h35m | 22h03m | 22h46m | 0h41m | 4h52m | 0.75 |
| 2024-08-15 | 4h54m | 5h37m | 22h01m | 22h44m | 1h26m | 4h54m | 0.84 |
| 2024-08-16 | 4h56m | 5h38m | 21h59m | 22h42m | 2h24m | 4h56m | 0.91 |
| 2024-08-17 | 4h58m | 5h40m | 21h57m | 22h39m | 3h35m | 4h58m | 0.96 |
| 2024-08-18 | 4h59m | 5h41m | 21h55m | 22h37m | 4h55m | 4h59m | 1.00 |
| 2024-08-19 | 5h01m | 5h43m | 21h54m | 22h35m | – | – | 1.00 |
| 2024-08-20 | 5h03m | 5h44m | 21h52m | 22h33m | – | – | 0.97 |
| 2024-08-21 | 5h05m | 5h46m | 21h50m | 22h31m | – | – | 0.92 |
| 2024-08-22 | 5h06m | 5h47m | 21h48m | 22h28m | – | – | 0.84 |
| 2024-08-23 | 5h08m | 5h48m | 21h46m | 22h26m | 22h26m | 22h29m | 0.74 |
| 2024-08-24 | 5h10m | 5h50m | 21h44m | 22h24m | 22h24m | 22h55m | 0.63 |
| 2024-08-25 | 5h12m | 5h51m | 21h42m | 22h22m | 22h22m | 23h26m | 0.52 |
| 2024-08-26 | 5h13m | 5h53m | 21h40m | 22h19m | 22h19m | – | 0.41 |
| 2024-08-27 | 5h15m | 5h54m | 21h38m | 22h17m | 22h17m | 0h06m | 0.31 |
| 2024-08-28 | 5h17m | 5h56m | 21h36m | 22h15m | 22h15m | 0h56m | 0.22 |
| 2024-08-29 | 5h18m | 5h57m | 21h34m | 22h13m | 22h13m | 1h56m | 0.14 |
| 2024-08-30 | 5h20m | 5h58m | 21h32m | 22h10m | 22h10m | 3h02m | 0.08 |
| 2024-08-31 | 5h21m | 6h00m | 21h30m | 22h08m | 22h08m | 4h12m | 0.03 |
Twilight calendar was generated using Cartes du Ciel (Sky Charts).
See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.
NASA Calendar of Planetary Events
Date Time Event
Aug 1 Th Venus: 15.9° E
1 Th 1:59 am Moon North Dec.: 28.5° N
3 Sa 9:22 pm Mars-Aldebaran: 4.9° N
4 Su 7:13 am New Moon
4 Su 6:56 pm Venus-Regulus: 1° N
5 Mo 6:04 pm Moon-Venus: 1.9° S
7 We 1:23 pm Mercury-Venus: 5.7° N
8 Th 9:06 pm Moon Descending Node
8 Th 9:32 pm Moon Apogee: 405300 km
10 Sa 5:34 am Moon-Spica: .8° S
12 Mo 9:38 am Perseid Shower: ZHR = 90
12 Mo 11:19 am First Quarter
14 We 12:38 am Moon-Antares: °
14 We 10:45 am Mars-Jupiter: .3° N
15 Th 4:10 pm Moon South Dec.: 28.5° S
18 Su 9:48 pm Mercury Inferior Conj.
19 Mo 2:26 pm Full Moon
20 Tu 10:54 pm Moon-Saturn: .4° S
21 We 1:05 am Moon Perigee: 360200 km
22 Th 6:27 am Moon Ascending Node
25 Su 10:54 pm Moon-Pleiades: .1° S
26 Mo 5:26 am Last Quarter
28 We 7:09 am Moon North Dec.: 28.6° N
30 Fr 12:47 am Moon-Pollux: 1.8° N
31 Sa 1:31 am Moon-Beehive: 3.3° S
Sep 1 Su Venus: 24.1° E
Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.
If you go to the above site, you can print out a list like the above for the entire year or calendar pages for your time zone.
Sun and Moon Rising and Setting Events
LU Ephemeris of Sky Events for Interlochen/TC August, 2024 Local time zone: EDT +-----------------------------------------------------------------------+ | DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM | | | RISE SET HOURS | END START |PHASE SET** TIME FRACTN| +=======================================================================+ |Thu 1| 06:29a 09:07p 14:38 | 10:22p 05:14a | Rise 04:03a 6%| |Fri 2| 06:30a 09:06p 14:35 | 10:21p 05:15a | Rise 05:12a 2%| |Sat 3| 06:31a 09:05p 14:33 | 10:19p 05:17a | Rise 06:22a 0%| +------+-----------------------+----------------+-----------------------+ |Sun 4| 06:33a 09:03p 14:30 | 10:17p 05:18a |New Set 09:37p 0%| |Mon 5| 06:34a 09:02p 14:28 | 10:16p 05:20a | Set 09:58p 2%| |Tue 6| 06:35a 09:01p 14:25 | 10:14p 05:21a | Set 10:15p 6%| |Wed 7| 06:36a 08:59p 14:23 | 10:12p 05:23a | Set 10:31p 11%| |Thu 8| 06:37a 08:58p 14:20 | 10:10p 05:24a | Set 10:47p 18%| |Fri 9| 06:38a 08:56p 14:17 | 10:09p 05:26a | Set 11:03p 26%| |Sat 10| 06:40a 08:55p 14:15 | 10:07p 05:27a | Set 11:21p 34%| +------+-----------------------+----------------+-----------------------+ |Sun 11| 06:41a 08:53p 14:12 | 10:05p 05:29a | Set 11:41p 44%| |Mon 12| 06:42a 08:52p 14:09 | 10:03p 05:30a |F Qtr Set 12:07a 54%| |Tue 13| 06:43a 08:50p 14:07 | 10:01p 05:32a | Set 12:41a 63%| |Wed 14| 06:44a 08:49p 14:04 | 09:59p 05:33a | Set 01:25a 73%| |Thu 15| 06:45a 08:47p 14:01 | 09:58p 05:35a | Set 02:23a 82%| |Fri 16| 06:47a 08:46p 13:58 | 09:56p 05:36a | Set 03:34a 90%| |Sat 17| 06:48a 08:44p 13:56 | 09:54p 05:38a | Set 04:54a 95%| +------+-----------------------+----------------+-----------------------+ |Sun 18| 06:49a 08:42p 13:53 | 09:52p 05:39a | Set 06:18a 99%| |Mon 19| 06:50a 08:41p 13:50 | 09:50p 05:41a |Full Rise 09:02p 100%| |Tue 20| 06:51a 08:39p 13:47 | 09:48p 05:42a | Rise 09:25p 98%| |Wed 21| 06:52a 08:37p 13:44 | 09:46p 05:43a | Rise 09:46p 93%| |Thu 22| 06:54a 08:36p 13:41 | 09:44p 05:45a | Rise 10:07p 85%| |Fri 23| 06:55a 08:34p 13:39 | 09:42p 05:46a | Rise 10:29p 76%| |Sat 24| 06:56a 08:32p 13:36 | 09:40p 05:48a | Rise 10:54p 65%| +------+-----------------------+----------------+-----------------------+ |Sun 25| 06:57a 08:30p 13:33 | 09:38p 05:49a | Rise 11:26p 54%| |Mon 26| 06:58a 08:29p 13:30 | 09:36p 05:51a |L Qtr Rise 12:06a 43%| |Tue 27| 06:59a 08:27p 13:27 | 09:34p 05:52a | Rise 12:55a 33%| |Wed 28| 07:01a 08:25p 13:24 | 09:32p 05:53a | Rise 01:55a 24%| |Thu 29| 07:02a 08:23p 13:21 | 09:30p 05:55a | Rise 03:02a 15%| |Fri 30| 07:03a 08:22p 13:18 | 09:28p 05:56a | Rise 04:11a 9%| |Sat 31| 07:04a 08:20p 13:15 | 09:26p 05:58a | Rise 05:20a 4%| +-----------------------------------------------------------------------+ * Nautical Twilight ** Moonrise or moonset, whichever occurs between sunset and sunrise
Generated using my LookingUp for DOS app.
Ephemeris: 07/31/2024 – Where are the naked-eye planets this week?
This is Ephemeris for Wednesday, July 31st. Today the Sun will be up for 14 hours and 40 minutes, setting at 9:09, and it will rise tomorrow at 6:29. The Moon, halfway from last quarter to new, will rise at 3:01 tomorrow morning.
Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus may still be too close to the direction of the Sun to be easily seen, it will set at 9:56 pm in the west-northwest. The best time to spot it will start about 9:30 pm or so, looking over a Lake Michigan horizon. Mercury now is too low and faint to be seen at that time. The rest of the planets are in the morning sky. By 5:30 tomorrow morning, or an hour before sunrise, Saturn will be in the south-southwest, Mars and Jupiter will make a small triangle with the bright star Aldebaran in the east with Mars on top and Jupiter on the left. Below and left of Jupiter will be the crescent Moon. Saturn may look disappointing in telescopes this year since rings are nearly edge on and appear almost as a line through the planet. Saturn will rise at 10:45 pm, Mars will rise at 1:56 am, and finally Jupiter at 2:20 am.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). They may be different for your location.
Addendum








