Archive
Ephemeris: 10/07/2024 – Comet Tsuchinshan-ATLAS will be visible starting Saturday Night
This is Ephemeris for Monday, October 7th. Today the Sun will be up for 11 hours and 22 minutes, setting at 7:11, and it will rise tomorrow at 7:50. The Moon, 3 days before first quarter, will set at 9:15 this evening.
In January of last year a Chinese observatory discovered a comet which was subsequently lost. A month and a half later another observatory in South Africa rediscovered it. That’s why the comet is named, Tsuchinshan-ATLAS after the two observatories. It was soon learned that the comet had a chance of becoming visible to the unaided eye in late September and October 2024, this month. Despite having a dimming episode earlier this year the comet promises to be naked eye and possibly even spectacular. The comet is moving from the south to the north and in a direction counter to the orbiting planets around the Sun. We will begin to see it low in the West after sunset starting Saturday.
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
The comet will pass almost directly between the Earth and the Sun on the evening of the 9th. It’ll be about halfway between the Earth and the Sun at that point. It should be picked up by the Solar and Heliospheric Observatory satellite (SOHO) which is orbiting the Earth-Sun L1 Lagrange point a million miles sunward from the Earth with its C3 coronagraph*. Then the comet’s tail should be pointing almost directly at the Earth. As the comet swings out away from the Sun it will also be more rapidly moving away from Earth. This is because the comet has an orbit that is counter to that of the orbits of the Earth and the rest of the planets around the Sun and will rapidly fade as it increases its distance.
A note on the discovery designation: C/2023 A3 is C for comet; 2023, the year of discovery; A3, third object reportedly discovered in the first half of January.
The SOHO Real-time GIF Movies webpage is: https://soho.nascom.nasa.gov/data/realtime/gif/. Select LASCO/C3. It provides a time-lapse image of the Sun’s corona taken at hourly intervals for about the last 4 days.
Ephemeris: 10/03/2024 – Capella rising
This is Ephemeris for Thursday, October 3rd. Today the Sun will be up for 11 hours and 34 minutes, setting at 7:18, and it will rise tomorrow at 7:45. The Moon, 1 day past new, will set at 7:33 this evening.
There is a bright star low in the northeast these evenings. It doesn’t seem to be rising very much over the course of the evening. This star is Capella, whose name means “little goat” and is part of the constellation Auriga the charioteer, which won’t completely rise for until about 11 PM. Capella is a circumpolar star meaning it appears to go around the North Pole of the sky, in a circle, as the Earth rotates but never sets. This is true for the Interlochen/Traverse City area and for latitudes north of the city of Ludington. Capella is slowly rising from the bottom of its circumpolar circle in the north, so it’s moving more horizontally than it is rising up. This motion was suspicious to one person who called me, who wondered what it was.
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: 10/02/2024 – Taking our weekly look at where the naked-eye planets are
This is Ephemeris for Wednesday, October 2nd. Today the Sun will be up for 11 hours and 37 minutes, setting at 7:20, and it will rise tomorrow at 7:43. The Moon is new today, and won’t be visible.
Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus might be spotted in the West southwest only 7° above the horizon at 7:45 PM, 35 minutes after sunset. It will set at 8:30. Saturn will be low in the east-southeast at that time, but you might have to wait another half hour for it to appear. Saturn may look disappointing in telescopes this year since its rings are nearly edge on and appearing as a line through the planet like it’s stapled onto the sky. Jupiter and Mars will be up in the morning sky, with Jupiter rising about 10:30 PM now in the east-northeast and by 7 AM tomorrow, Jupiter will be brighter than the winter stars high in the south. Mars will be left of Jupiter. Comet Tsuchinshan-ATLAS is very low in the east at that hour, but probably too faint to spot.
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: 10/01/2024 – Previewing the skies of October
This is Ephemeris for Tuesday, October 1st. Today the Sun will be up for 11 hours and 40 minutes, setting at 7:22, and it will rise tomorrow at 7:42. The Moon, 1 day before new, will rise at 7:30 tomorrow morning.
Let’s look at the skies for the month of October. The Sun will still be moving south rapidly. Daylight hours in the Interlochen/Traverse City area and will drop from 11 hours and 40 minutes today to 10 hours, 11 minutes at month’s end. The altitude of the Sun above the southern horizon at local noon will be 42 degrees today, and will descend to 31 degrees on Halloween, also in the Interlochen area. Sunrise times will increase from 7:41 today all the way to 8:20 a.m. in Interlochen and Traverse City on the 31st. Sunset times will decrease from 7:22 p.m. today to 6:32 on Halloween.
The big event of October will be the appearance of Comet Tsuchinshan-ATLAS in the evening sky which may become quite bright, but being a comet, all bets are off until you actually see it. It will become visible in the evening sky starting October 12th.
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
October path of Comet Tsuchinshan-ATLAS
October Evening Star Chart
The planets and stars are plotted for the 15th at 9 p.m. EDT in the evening and 6 a.m. for the morning chart. 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.
October Morning Star Chart
or 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.
- The Summer Triangle is in red.
- DracR – Draconid Radiant – Peaks the 8th – Zenithal Hourly Rate < 10 with rare outbursts of a thousand an hour. It’s hindered this year by the full moon.
- OriR – Orionid Radiant – Peak 21st – Zenithal Hourly Rate = 20
Twilight Limits, Nautical and Astronomical
| EDT | |||||||
| Morning | Twilight | Evening | Twilight | Dark | Night | Moon | |
| Date | Astro. | Nautical | Nautical | Astro. | Start | End | Illum. |
| 2024-10-01 | 6h06m | 6h40m | 20h28m | 21h03m | 21h03m | 6h06m | 0.00 |
| 2024-10-02 | 6h07m | 6h41m | 20h27m | 21h01m | 21h01m | 6h07m | 0.00 |
| 2024-10-03 | 6h08m | 6h42m | 20h25m | 20h59m | 20h59m | 6h08m | 0.02 |
| 2024-10-04 | 6h09m | 6h43m | 20h23m | 20h57m | 20h57m | 6h09m | 0.05 |
| 2024-10-05 | 6h11m | 6h45m | 20h21m | 20h55m | 20h55m | 6h11m | 0.10 |
| 2024-10-06 | 6h12m | 6h46m | 20h19m | 20h53m | 20h53m | 6h12m | 0.17 |
| 2024-10-07 | 6h13m | 6h47m | 20h17m | 20h51m | 21h15m | 6h13m | 0.25 |
| 2024-10-08 | 6h14m | 6h48m | 20h16m | 20h50m | 22h01m | 6h14m | 0.34 |
| 2024-10-09 | 6h16m | 6h50m | 20h14m | 20h48m | 22h58m | 6h16m | 0.44 |
| 2024-10-10 | 6h17m | 6h51m | 20h12m | 20h46m | – | 6h17m | 0.55 |
| 2024-10-11 | 6h18m | 6h52m | 20h10m | 20h44m | 0h06m | 6h18m | 0.65 |
| 2024-10-12 | 6h19m | 6h53m | 20h09m | 20h43m | 1h22m | 6h19m | 0.76 |
| 2024-10-13 | 6h21m | 6h54m | 20h07m | 20h41m | 2h42m | 6h21m | 0.85 |
| 2024-10-14 | 6h22m | 6h56m | 20h05m | 20h39m | 4h03m | 6h22m | 0.92 |
| 2024-10-15 | 6h23m | 6h57m | 20h04m | 20h37m | 5h25m | 6h23m | 0.98 |
| 2024-10-16 | 6h24m | 6h58m | 20h02m | 20h36m | – | – | 1.00 |
| 2024-10-17 | 6h26m | 6h59m | 20h00m | 20h34m | – | – | 0.99 |
| 2024-10-18 | 6h27m | 7h01m | 19h55m | 20h33m | – | – | 0.96 |
| 2024-10-19 | 6h28m | 7h02m | 19h53m | 20h31m | – | – | 0.89 |
| 2024-10-20 | 6h29m | 7h03m | 19h52m | 20h29m | 20h29m | 20h40m | 0.81 |
| 2024-10-21 | 6h31m | 7h04m | 19h50m | 20h28m | 20h28m | 21h36m | 0.72 |
| 2024-10-22 | 6h32m | 7h05m | 19h49m | 20h26m | 20h26m | 22h41m | 0.62 |
| 2024-10-23 | 6h33m | 7h07m | 19h47m | 20h25m | 20h25m | 23h51m | 0.51 |
| 2024-10-24 | 6h34m | 7h08m | 19h46m | 20h23m | 20h23m | – | 0.41 |
| 2024-10-25 | 6h35m | 7h09m | 19h44m | 20h22m | 20h22m | 1h01m | 0.32 |
| 2024-10-26 | 6h37m | 7h10m | 19h43m | 20h21m | 20h21m | 2h10m | 0.23 |
| 2024-10-27 | 6h38m | 7h12m | 19h42m | 20h19m | 20h19m | 3h16m | 0.16 |
| 2024-10-28 | 6h39m | 7h13m | 19h40m | 20h18m | 20h18m | 4h19m | 0.10 |
| 2024-10-29 | 6h40m | 7h14m | 19h39m | 20h17m | 20h17m | 5h22m | 0.05 |
| 2024-10-30 | 6h41m | 7h15m | 19h37m | 20h15m | 20h15m | 6h25m | 0.02 |
| 2024-10-31 | 6h43m | 7h16m | 19h36m | 20h14m | 20h14m | 6h43m | 0.00 |
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
Oct 1 Tu Venus: 31.4° E
2 We 7:52 am Moon Descending Node
2 We 2:46 pm Annular Solar Eclipse
2 We 2:49 pm New Moon
2 We 3:40 pm Moon Apogee: 406500 km
5 Sa 4:26 pm Moon-Venus: 3.3° N
7 Mo 2:48 pm Moon-Antares: .2° N
9 We 7:53 am Moon South Dec.: 28.7° S
10 Th 2:55 pm First Quarter
14 Mo 2:05 pm Moon-Saturn: .1° S
16 We 3:05 am Moon Ascending Node
16 We 8:46 pm Moon Perigee: 357200 km
17 Th 7:26 am Full Moon
18 Fr 7:50 pm Mars-Pollux: 5.7° S
19 Sa 3:59 pm Moon-Pleiades: .1° S
21 Mo 1:58 am Orionid Shower: ZHR = 20
21 Mo 8:50 pm Moon North Dec.: 28.7° N
23 We 1:16 pm Moon-Pollux: 1.8° N
23 We 3:55 pm Moon-Mars: 4.2° S
24 Th 4:03 am Last Quarter
24 Th 1:35 pm Moon-Beehive: 3.3° S
25 Fr 7:43 pm Venus-Antares: 3.1° N
29 Tu 12:44 pm Moon Descending Node
29 Tu 5:50 pm Moon Apogee: 406200 km
Nov 1 Fr Venus: 38.2° E
All event times are given for UTC-4 hr: Eastern Daylight Saving Time.
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 Times
LU Ephemeris of Sky Events for Interlochen/TC
October, 2024 Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM |
| | RISE SET HOURS | END START |PHASE SET** TIME FRACTN|
+=======================================================================+
|Tue 1| 07:41a 07:22p 11:40 | 08:25p 06:38a | Rise 07:30a 1%|
|Wed 2| 07:42a 07:20p 11:37 | 08:23p 06:39a |New Set 07:16p 0%|
|Thu 3| 07:43a 07:18p 11:34 | 08:21p 06:40a | Set 07:33p 1%|
|Fri 4| 07:45a 07:16p 11:31 | 08:19p 06:42a | Set 07:51p 4%|
|Sat 5| 07:46a 07:14p 11:28 | 08:17p 06:43a | Set 08:13p 9%|
+------+-----------------------+----------------+-----------------------+
|Sun 6| 07:47a 07:13p 11:25 | 08:15p 06:44a | Set 08:40p 15%|
|Mon 7| 07:48a 07:11p 11:22 | 08:14p 06:45a | Set 09:15p 23%|
|Tue 8| 07:50a 07:09p 11:19 | 08:12p 06:47a | Set 10:00p 32%|
|Wed 9| 07:51a 07:07p 11:16 | 08:10p 06:48a | Set 10:57p 42%|
|Thu 10| 07:52a 07:05p 11:13 | 08:08p 06:49a |F Qtr Set 12:05a 52%|
|Fri 11| 07:53a 07:04p 11:10 | 08:07p 06:50a | Set 01:22a 63%|
|Sat 12| 07:55a 07:02p 11:07 | 08:05p 06:51a | Set 02:41a 73%|
+------+-----------------------+----------------+-----------------------+
|Sun 13| 07:56a 07:00p 11:04 | 08:03p 06:53a | Set 04:03a 83%|
|Mon 14| 07:57a 06:58p 11:01 | 08:02p 06:54a | Set 05:24a 91%|
|Tue 15| 07:58a 06:57p 10:58 | 08:00p 06:55a | Set 06:47a 97%|
|Wed 16| 08:00a 06:55p 10:55 | 07:58p 06:56a | Set 08:11a 100%|
|Thu 17| 08:01a 06:53p 10:52 | 07:57p 06:58a |Full Rise 06:53p 100%|
|Fri 18| 08:02a 06:52p 10:49 | 07:55p 06:59a | Rise 07:21p 96%|
|Sat 19| 08:04a 06:50p 10:46 | 07:54p 07:00a | Rise 07:55p 91%|
+------+-----------------------+----------------+-----------------------+
|Sun 20| 08:05a 06:48p 10:43 | 07:52p 07:01a | Rise 08:40p 83%|
|Mon 21| 08:06a 06:47p 10:40 | 07:50p 07:02a | Rise 09:35p 74%|
|Tue 22| 08:08a 06:45p 10:37 | 07:49p 07:04a | Rise 10:40p 64%|
|Wed 23| 08:09a 06:44p 10:34 | 07:47p 07:05a | Rise 11:50p 53%|
|Thu 24| 08:10a 06:42p 10:31 | 07:46p 07:06a |L Qtr Rise 01:01a 43%|
|Fri 25| 08:12a 06:40p 10:28 | 07:45p 07:07a | Rise 02:09a 34%|
|Sat 26| 08:13a 06:39p 10:25 | 07:43p 07:09a | Rise 03:15a 25%|
+------+-----------------------+----------------+-----------------------+
|Sun 27| 08:14a 06:37p 10:23 | 07:42p 07:10a | Rise 04:19a 17%|
|Mon 28| 08:16a 06:36p 10:20 | 07:40p 07:11a | Rise 05:22a 11%|
|Tue 29| 08:17a 06:34p 10:17 | 07:39p 07:12a | Rise 06:24a 6%|
|Wed 30| 08:18a 06:33p 10:14 | 07:38p 07:14a | Rise 07:28a 2%|
|Thu 31| 08:20a 06:32p 10:11 | 07:36p 07:15a | Rise 08:34a 0%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise
Generated using my LookingUp for DOS program.
Ephemeris: 09/30/2024 – Andromeda’s treasure, its great galaxy
This is Bob Moler with Ephemeris for Monday, September 30th. Today the Sun will be up for 11 hours and 43 minutes, setting at 7:24, and it will rise tomorrow at 7:41. The Moon, 2 days before new, will rise at 6:27 tomorrow morning. | For at least the last thousand or so years a fuzzy spot in the constellation of Andromeda has been known. It was known as the Great Andromeda Nebula until about 100 years ago. Nebula means cloud, and it belonged to the Milky Way. At that time it was finally recognized as another Milky Way just like ours. So the word to call it was galaxy, a word that means Milky Way. It looks to be among the stars of Andromeda, but it’s far beyond the stars that we make of the constellation Andromeda. Current estimates place it at about two and a half million light years away, well beyond the stars that we see in Andromeda that range to only a few thousand light years distance. It will collide with our galaxy in about 4 billion years.
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: 09/27/2024 – Finding Andromeda
This is Ephemeris for Friday, September 27th. Today the Sun will be up for 11 hours and 53 minutes, setting at 7:29, and it will rise tomorrow at 7:37. The Moon, 3 days past last quarter, will rise at 3:11 tomorrow morning.
The constellation of Andromeda is famous mainly for the galaxy visible to the naked eye that is contained within it, called the Great Andromeda Galaxy, which is actually visible to the naked eye. Andromeda is found in the east northeast these evenings connected to the Great Square of Pegasus, the square of stars standing on one corner in the east. It shares a star with that square called Alpheratz, the leftmost star, and from that star two curved lines of stars are seen to the left that is the body of Andromeda. She was a Princess and daughter of Queen Cassiopeia, and was fated to be devoured by the monster Cetus. She was saved by the hero Perseus who flew in on his flying horse Pegasus.
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: 09/26/2024 – Finding Cassiopeia the queen
This Ephemeris for Thursday, September 26th. Today the Sun will be up for 11 hours and 56 minutes, setting at 7:31, and it will rise tomorrow at 7:36. The Moon, 2 days past last quarter, will rise at 2:02 tomorrow morning.
High in the northeast sky at 9:00 PM can be found the constellation of Cassiopeia the queen. Its stars make a letter W in the sky. It is circumpolar, meaning that it never sets, as it appears to move around the North Pole of the sky. In the summer it is a W low in the north. It becomes kind of an open and angular number 3 in the autumn. In the winter it is overhead and looks like an M. In springtime it looks like the Greek capital letter Sigma in the northwest. I will visit Cassiopeia later this autumn and relate her story and other autumn constellations including her daughter Andromeda, husband King Cepheus, future son-in-law Perseus and his horse Pegasus, and the sea monster, Cetus.
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: 09/25/2024 – Looking for the naked-eye planets for this week
This is Ephemeris for Wednesday, September 25th. Today the Sun will be up for 11 hours and 59 minutes, setting at 7:33, and it will rise tomorrow at 7:35. The Moon, 1 day past last quarter, will rise at 12:53 tomorrow morning.
Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus might be spotted in the West southwest only 6° above the horizon at 8 PM, 30 minutes after sunset. It will set at 8:38. Saturn will be low in the east-southeast at that time, but you might have to wait another half hour for it to appear. Saturn may look disappointing in telescopes this year since its rings are nearly edge on and appearing as a line through the planet like it’s stapled onto the sky. Jupiter and Mars will be up in the morning sky, with Jupiter rising about 11 PM now and by 6:30 AM tomorrow, Jupiter will be brighter than the winter stars in the south-southeast. Mars and the Moon will be left and below Jupiter.
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: 09/24/2024 – Pegasus is rising on autumn evenings
This is Ephemeris for Tuesday, September 24th. Today the Sun will be up for 12 hours and 2 minutes, setting at 7:35, and it will rise tomorrow at 7:34. The Moon, at last quarter today, will rise at 11:47 this evening.
While we’ve been watching the stars and constellations of summer and the Milky Way, the constellations of autumn have been sneaking up on us from the east. About halfway up the sky in the east at 9 PM is one of the greatest constellations of autumn, Pegasus the flying horse. Her body or at least the front part of it is a large square of stars called the Great Square of Pegasus. It is an almost perfect rectangle. However, as she’s rising, it’s standing on one corner. From the upper star are her front legs, from the rightmost star her neck and head extend in the stars. And from the left star of the square are what might look like her hind legs but aren’t. Only half of her body is in the stars. It’s another constellation, Andromeda, which we’ll talk about later.
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: 09/23/2024 – Scanning the Milky Way with binoculars
This is Ephemeris for Monday, September 23rd. Today the Sun will be up for 12 hours and 5 minutes, setting at 7:37, and it will rise tomorrow at 7:33. The Moon, 1 day before last quarter, will rise at 10:50 this evening.
Now that the Moon has fled the early evening skies the Milky Way is showing up again, if you’re at a dark site. I’ve always said that August and September are the best times to view what I call the summer Milky Way, even now that it’s not technically summer anymore. The Teapot asterism in the constellation of Sagittarius is low in the south-southeast, pouring its tea on the horizon. It is in that direction we are looking towards the center of our Milky Way Galaxy. The Summer Triangle is high in the South with Vega and Deneb, two of its stars near the zenith. All the Milky Way is an invitation to scan it with the pair of binoculars or a very low power telescope. One doesn’t need a chart. Just wander through the Milky Way to find many star clusters, groups of stars and nebulae.
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 (Some binocular wonders)
The Coathanger
The North American Nebula
Bob Moler's Ephemeris Blog 