Archive

Archive for October, 2023

Ephemeris: 10/31/2023 – Previewing November skies

October 31, 2023 Comments off

This is Ephemeris for Halloween, Tuesday, October 31st. Today the Sun will be up for 10 hours and 13 minutes, setting at 6:33, and it will rise tomorrow at 8:20. The Moon, 3 days past full, will rise at 8:09 this evening.

Let’s take a look at November skies. The time change back to standard time will set us back an hour on sunrise and sunset times, so it’ll be brighter in the morning and darker in the evening starting Sunday, the 5th. Out east in New York City, the Sun is already setting before 5 p.m. It will never set that early here. The Sun will be up for 10 hours 11 minutes on the 1st, and that will dwindle down to 9 hours and 5 minutes at month’s end. The Sun reaches 30 ½ degrees above the southern horizon at local apparent solar noon on the 1st, which is around 12:25 p.m. this month. It will drop to 23 ½ degrees on the 30th. As the Earth orbits the Sun now, the North Pole of the Earth is tilting farther and farther away from the Sun providing us with less of its heat. The Leonid meteor shower, peaking on the 18th, is expected to be lackluster this year. We are about 9 or 10 years away from the time that the Leonids become spectacular again as they do every 33 or so years. Jupiter will reach opposition from the Sun on the 2nd, and Mars will be in conjunction with the Sun on the 17th.

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

November Evening Star Chart

Star Chart for November evenings, 2023 (9 pm EST November 15, 2023). Click on the image to enlarge it. Created using my LookingUp program.

The planets and stars are plotted for the 15th at 9 p.m. EST 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 45 minutes earlier than the current time.

Star Chart for November mornings, 2023 (6 a.m. EST November 15, 2023). Click on the image to enlarge it. Created using my LookingUp program.

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.
  • Follow the arc of the handle of the Big Dipper to the star Arcturus
  • The Summer Triangle is in red.
  • TauR on the evening star chart can be used as the radiant for the North and South Taurid meteor showers. For dates see NASA Calendar of Planetary Events below
  • LeoR on the morning star chart is the radiant of the Leonid meteor shower, which peaks on the morning of the 18th.

Twilight Limits, Nautical and Astronomical

      EDT/EST        
  Morning Twilight Evening Twilight Dark Night Moon
Date Astro. Nautical Nautical Astro. Start End Illum.
2023-11-01 6h47m 7h21m 19h40m 20h14m 20h14m 20h59m 0.79
2023-11-02 6h48m 7h22m 19h39m 20h12m 20h12m 21h57m 0.70
2023-11-03 6h49m 7h23m 19h37m 20h11m 20h11m 23h01m 0.61
2023-11-04 6h50m 7h24m 19h36m 20h10m 20h10m 0.52
2023-11-05 5h52m 6h26m 18h35m 19h09m 19h09m 0.42
2023-11-06 5h53m 6h27m 18h34m 19h08m 19h08m 0h13m 0.33
2023-11-07 5h54m 6h28m 18h33m 19h07m 19h07m 1h19m 0.24
2023-11-08 5h55m 6h29m 18h32m 19h06m 19h06m 2h23m 0.17
2023-11-09 5h56m 6h30m 18h31m 19h05m 19h05m 3h26m 0.10
2023-11-10 5h57m 6h32m 18h30m 19h04m 19h04m 4h31m 0.05
2023-11-11 5h59m 6h33m 18h29m 19h03m 19h03m 5h38m 0.01
2023-11-12 6h00m 6h34m 18h28m 19h02m 19h02m 6h00m 0.00
2023-11-13 6h01m 6h35m 18h27m 19h01m 19h01m 6h01m 0.01
2023-11-14 6h02m 6h36m 18h26m 19h00m 19h00m 6h02m 0.04
2023-11-15 6h03m 6h38m 18h25m 18h59m 18h59m 6h03m 0.09
2023-11-16 6h04m 6h39m 18h24m 18h59m 19h35m 6h04m 0.16
2023-11-17 6h05m 6h40m 18h23m 18h58m 20h46m 6h05m 0.26
2023-11-18 6h07m 6h41m 18h23m 18h57m 22h04m 6h07m 0.36
2023-11-19 6h08m 6h42m 18h22m 18h56m 23h24m 6h08m 0.47
2023-11-20 6h09m 6h43m 18h21m 18h56m 6h09m 0.59
2023-11-21 6h10m 6h45m 18h20m 18h55m 0h43m 6h10m 0.70
2023-11-22 6h11m 6h46m 18h20m 18h55m 2h01m 6h11m 0.80
2023-11-23 6h12m 6h47m 18h19m 18h54m 3h17m 6h12m 0.88
2023-11-24 6h13m 6h48m 18h19m 18h54m 4h34m 6h13m 0.94
2023-11-25 6h14m 6h49m 18h18m 18h53m 5h51m 6h14m 0.98
2023-11-26 6h15m 6h50m 18h18m 18h53m 1.00
2023-11-27 6h16m 6h51m 18h17m 18h52m 0.99
2023-11-28 6h17m 6h52m 18h17m 18h52m 0.96
2023-11-29 6h18m 6h53m 18h17m 18h52m 0.91
2023-11-30 6h19m 6h54m 18h16m 18h51m 18h51m 19h45m 0.85

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

Nov  1  We            Venus: 46.2° W
     2  Th  12:12 am  Moon North Dec.: 28.3° N
     2  Th  10:44 pm  Jupiter Opposition
     3  Fr   1:31 pm  Moon-Pollux: 1.6° N
     5  Su   3:37 am  Last Quarter
     5  Su   7:17 pm  South Taurid Shower: ZHR = 10
     6  Mo   4:49 pm  Moon Apogee: 404,600 km
     9  Th   4:28 am  Moon-Venus: 1.1° S
    11  Sa  12:09 am  Moon-Spica: 2.6° S
    11  Sa   3:49 am  Moon Descending Node
    12  Su   6:34 pm  North Taurid Shower: ZHR = 15
    13  Mo   4:27 am  New Moon
    13  Mo  12:32 pm  Uranus Opposition
    16  Th   9:45 am  Moon South Dec.: 28.2° S
    16  Th   4:17 pm  Mercury-Antares: 2.5° N
    17  Fr  11:48 pm  Mars Solar Conjunction
    18  Sa  12:51 am  Leonid Shower: ZHR = 15
    20  Mo   5:50 am  First Quarter
    20  Mo   9:02 am  Moon-Saturn: 2.8° N
    21  Tu   4:03 pm  Moon Perigee: 369,800 km
    24  Fr   6:02 am  Moon Ascending Node
    25  Sa   6:10 am  Moon-Jupiter: 2.8° S
    26  Su   7:02 pm  Moon-Pleiades: 1.2° N
    27  Mo   4:16 am  Full Beaver Moon
    29  We   5:29 am  Venus-Spica: 4.2° N
    29  We   9:08 am  Moon North Dec.: 28.2° N
    30  Th  10:23 pm  Moon-Pollux: 1.7° N
Dec  1  Fr            Venus: 42.9° W

All event times for November 1-4 are given for UTC-4 Eastern Daylight Saving Time. For dates after that, times are given for UTC-5 Eastern Standard 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
November, 2023    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Wed  1| 08:20a  06:31p  10:11 | 07:36p  07:15a |      Rise 08:58p   81%|
|Thu  2| 08:21a  06:30p  10:08 | 07:35p  07:16a |      Rise 09:57p   72%|
|Fri  3| 08:23a  06:28p  10:05 | 07:34p  07:18a |      Rise 11:00p   63%|
|Sat  4| 08:24a  06:27p  10:03 | 07:32p  07:19a |      Rise 12:07a   53%|
+------+-----------------------+----------------+-----------------------+
| EST  |      Time Change      |                |                       |
|Sun  5| 07:25a  05:26p  10:00 | 06:31p  06:20a |L Qtr Rise 12:13a   44%|
|Mon  6| 07:27a  05:25p  09:57 | 06:30p  06:21a |      Rise 01:18a   35%|
|Tue  7| 07:28a  05:23p  09:55 | 06:29p  06:22a |      Rise 02:22a   26%|
|Wed  8| 07:30a  05:22p  09:52 | 06:28p  06:24a |      Rise 03:26a   18%|
|Thu  9| 07:31a  05:21p  09:49 | 06:27p  06:25a |      Rise 04:31a   11%|
|Fri 10| 07:32a  05:20p  09:47 | 06:26p  06:26a |      Rise 05:38a    6%|
|Sat 11| 07:34a  05:19p  09:44 | 06:25p  06:27a |      Rise 06:47a    2%|
+------+-----------------------+----------------+-----------------------+
|Sun 12| 07:35a  05:17p  09:42 | 06:24p  06:28a |      Rise 08:00a    0%|
|Mon 13| 07:36a  05:16p  09:40 | 06:23p  06:30a |New   Set  05:13p    0%|
|Tue 14| 07:38a  05:15p  09:37 | 06:22p  06:31a |      Set  05:48p    3%|
|Wed 15| 07:39a  05:14p  09:35 | 06:21p  06:32a |      Set  06:35p    8%|
|Thu 16| 07:40a  05:13p  09:32 | 06:20p  06:33a |      Set  07:34p   15%|
|Fri 17| 07:42a  05:12p  09:30 | 06:20p  06:34a |      Set  08:45p   24%|
|Sat 18| 07:43a  05:12p  09:28 | 06:19p  06:36a |      Set  10:03p   34%|
+------+-----------------------+----------------+-----------------------+
|Sun 19| 07:44a  05:11p  09:26 | 06:18p  06:37a |      Set  11:23p   45%|
|Mon 20| 07:46a  05:10p  09:24 | 06:18p  06:38a |F Qtr Set  12:42a   56%|
|Tue 21| 07:47a  05:09p  09:22 | 06:17p  06:39a |      Set  02:00a   67%|
|Wed 22| 07:48a  05:08p  09:20 | 06:16p  06:40a |      Set  03:17a   78%|
|Thu 23| 07:50a  05:08p  09:18 | 06:16p  06:41a |      Set  04:33a   86%|
|Fri 24| 07:51a  05:07p  09:16 | 06:15p  06:42a |      Set  05:51a   93%|
|Sat 25| 07:52a  05:06p  09:14 | 06:15p  06:43a |      Set  07:09a   98%|
+------+-----------------------+----------------+-----------------------+
|Sun 26| 07:53a  05:06p  09:12 | 06:14p  06:45a |      Set  08:25a  100%|
|Mon 27| 07:54a  05:05p  09:10 | 06:14p  06:46a |Full  Rise 05:01p   99%|
|Tue 28| 07:56a  05:05p  09:08 | 06:13p  06:47a |      Rise 05:47p   97%|
|Wed 29| 07:57a  05:04p  09:07 | 06:13p  06:48a |      Rise 06:42p   92%|
|Thu 30| 07:58a  05:04p  09:05 | 06:13p  06:49a |      Rise 07:44p   86%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

Generated using my LookingUp for DOS program.

Ephemeris: 10/30/2023 – Just in time for Halloween – Algol the Demon Star

October 30, 2023 Comments off

This is Ephemeris for Monday, October 30th. Today the Sun will be up for 10 hours and 16 minutes, setting at 6:34, and it will rise tomorrow at 8:19. The Moon, 2 days past full, will rise at 7:29 this evening.

Not all the ghosts and goblins out tomorrow night will be children. One will be out every night because it’s a star. Its name is Algol, from the Arabic for Ghoul Star or Demon Star. It’s normally the second brightest star in the constellation Perseus the hero, visible in the northeast this evening. The star is located where artists have drawn the severed head of Medusa, whom he had slain. Medusa was so ugly that she turned all who gazed upon her to stone. Algol is her still glittering eye. The star got these names before astronomers found out what was wrong with it. They found out that it does a slow wink every two days, 21 hours. That’s because Algol is two stars that eclipse each other. Her next evening wink will be its dimmest at 10:12 p.m. this Wednesday, November 1st.

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

For predictions of the minima of Algol for your time zone and for Universal Time (UT) go here: http://www.astropical.space/algol.php

Algol Finder Animation
Algol Finder Animation for around 8 pm in the later part of October and early November (7 pm after the EST time change on the first Sunday in November). Created using Stellarium and GIMP.
Perseus and the head of Medusa from the 1690 Uranographia by Johannes Hevelius.
Perseus and the head of Medusa from the 1690 Uranographia by Johannes Hevelius. Note that the image is mirror reversed. This mimicked the image on a celestial globe, looking from outside the globe. Note a couple of extra constellations: a small triangle below Triangulum, and Musca the fly. There is a Musca constellation in the southern hemisphere. This image was found with the article on Algol on Wikipedia.
Eclipsing Binary Star
Animation of an eclipsing binary star like Algol. Credit: Wikimedia Commons h/t Earth and Sky.

Ephemeris: 10/27/2023 – Report on October 14th’s partial solar eclipse and looking forward

October 27, 2023 Comments off

This is Ephemeris for Friday, October 27th. Today the Sun will be up for 10 hours and 25 minutes, setting at 6:38, and it will rise tomorrow at 8:15. The Moon, 1 day before full, will set at 7:55 tomorrow morning.

Two weeks ago tomorrow we had a partial eclipse of the Sun. Unfortunately around here it was pretty cloudy. I went to the Betsie Valley District Library knowing it was cloudy and brought a program to talk about mainly eclipses that I’ve seen and a preview of next April’s eclipse, which would be even better than the one we had two weeks ago. Towards the end of my talk I was looking out towards my audience and windows. I was the only one who could see out those windows, because I was facing that direction and I saw shadows. Sure enough the Sun came out, so we all piled out with our eclipse glasses and saw the maximum of the eclipse for maybe 15 minutes before it clouded up again. So the event was indeed a success.

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

Eclipse Map
The paths are maximum for eclipse for both October 14th’s annular eclipse, going down from upper left to lower right and April 8th next year’s total solar eclipse the path from lower left to upper right. As you can see, the total eclipse path will pass through Indiana and Ohio among other states The path of totality will just clip Michigan’s southeastern corner, most of which is actually in Lake Erie. It is well within a day’s drive from Northern Michigan. However, the chances are for better weather the farther south one goes. That’s a statistical chance, but no guarantees.

Below is a file to show April 8, 2024 eclipse path on Google Earth. It can be saved or used to bring up Google Earth. The file was created using Stellarium.

http://ephemeris.bjmoler.org/solareclipse-2024-4-8.kml

Ephemeris: 10/26/2023 – A closer look at Jupiter’s moon Io

October 26, 2023 Comments off

This is Ephemeris for Thursday, October 26th. Today the Sun will be up for 10 hours and 28 minutes, setting at 6:40, and it will rise tomorrow at 8:13. The Moon, 2 days before full, will set at 6:36 tomorrow morning.

My favorite moon of Jupiter has been Io ever since the Voyager 1 spacecraft discovered volcanoes on it. It turns out that Io is the most volcanic body in the solar system and perhaps the least studied of the Galilean moons of Jupiter. Most of the probes that have swung by or orbited Jupiter never got very close to Io, so we never really got a good close look at it. Well, now we are getting that closer look. The Juno spacecraft, which was sent to Jupiter to work out the interior of Jupiter using gravitational effects on its orbit, has now completed its main mission and its orbit has precessed so that now comes close to Io. The Juno spacecraft has a camera, mainly there for the public, which is showing amazing closeups of this moon.

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

Io from Juno
This image of Io was recently sent back by the Juno spacecraft currently orbiting Jupiter. In the next few months we’ll be getting even closer images. Credit: NASA/JPL. Via Universe Today.
Io from Galileo
This image of Io was taken back in 1997 by the Galileo Jupiter orbiter. As can be seen, the resolution isn’t as quite as good as the Juno photo. It never got as close to Io as the Juno spacecraft is or will be in the next few months and the CCD technology of the detector wasn’t as good as what we have today, although the optics of the camera probably were a lot better. Near the top of the image can be seen a plume from of an active volcano. Credit: NASA/JPL, DLR. Via Universe Today.

Ephemeris: 10/25/2023 – Where have the naked-eye planets wandered off to?

October 25, 2023 Comments off

This is Bob Moler with Ephemeris for Wednesday, October 25th. Today the Sun will be up for 10 hours and 30 minutes, setting at 6:42, and it will rise tomorrow at 8:12. The Moon, 3 days before full, will set at 5:16 tomorrow morning.

Let’s find out where the naked-eye planets have wandered off to this week. Three of those five planets are now visible, but Mars sets too close to sunset to be seen, and Mercury rises too close to sunrise. Saturn is the sole official evening planet visible. It can be spotted in the southeast to south in the evening. And it will still be visible in the morning hours until it sets at 2:49 am. Saturn is seen against the stars of Aquarius this year and next. Jupiter and Venus are the visible morning planets. Jupiter, still a morning planet for one more week, will rise at 7:04 pm. It’s in Aries this year. Jupiter has to rise before sunset to be an evening planet. Venus, the brilliant morning star, will rise in the east-northeast at 4:09 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

Jupiter and Saturn with the gibbous Moon tonight at 9 pm, October 25th 2023. Created using Stellarium.
The moon As it might be seen in a small telescope or binoculars, with selected features labeled, at 9 pm this evening, October 25th 2023. Created using Stellarium, LibreOffice Draw, and GIMP.
Venus as seen in the sky at 7:00 tomorrow morning, October 26th 2023. It’s seen below constellation of Leo the lion a constellation of spring evenings. Jupiter, not shown, is low in the west at that hour. Created using Stellarium.
Telescopic Saturn, Jupiter and Venus (north up) as they would be seen in a small telescope, with the same magnification. At 9 pm October 25, 2023, for Saturn and Jupiter, and 7 am October 26, for Venus. Apparent diameters: Saturn 17.97″, its rings 41.87″; Jupiter 49.41″; and Venus 23.41″ and is 51.9% illuminated. Note that for Jupiter Europa will disappear in Jupiter’s shadow at 11:33 pm and end its occultation by Jupiter on the other side at 2:16 am; Io will enter Jupiter’s shadow at 6:25 am. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts). Jupiter satellite event timings were taken from https://www.projectpluto.com/jevent.htm
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on October 25, 2023. The night ends on the left with sunrise on the 26th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.

Ephemeris: 10/24/2023 – We might see a bright nova soon

October 24, 2023 Comments off

This is Ephemeris for Tuesday, October 24th. Today the Sun will be up for 10 hours and 33 minutes, setting at 6:43, and it will rise tomorrow at 8:11. The Moon, 3 days past first quarter, will set at 3:57 tomorrow morning.

There is a star in the northern constellation of Corona Borealis the Northern Crown which we see normally on spring and summer evenings that is a recurring nova. A nova is a star that suddenly brightens from invisibility to visibility and soon fades. It is caused by a white dwarf orbiting with a larger, star siphoning off gases from the larger star until it builds up enough to create a thermonuclear explosion. This may not affect the star and may run through the process repeatedly. These are called reoccurring novae, and this one is designated T Coronae Borealis. It’s usually close to 11th magnitude which is hard to find even in binoculars to become one of the 50 brightest stars in the sky, as early as next year.

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

This animated GIF shows the constellations of Hercules, Corona Borealis and Boötes from left to right. Flashing on and off is T Coronae Borealis (T CrB). It is shown at its approximate maximum magnitude, about the same brightness as Alphecca. Created using Stellarium and GIMP.

What got me onto this is an article from Universe Today for September 8th by Jon Voisey: A Medieval Manuscript Likely Hides a Record of an Impending Recurrent Nova. Another source for this Nova is to look up T CrB on Wikipedia. See below:

https://en.wikipedia.org/wiki/T_Coronae_Borealis

Ephemeris: 10/23/2023 – Venus is at its greatest separation from the Sun in the morning

October 23, 2023 Comments off

This is Ephemeris for Monday, October 23rd. Today the Sun will be up for 10 hours and 36 minutes, setting at 6:45, and it will rise tomorrow at 8:09. The Moon, 2 days past first quarter, will set at 2:36 tomorrow morning.

Our brilliant morning planet Venus will reach its greatest apparent angle from the Sun later today. It’s called the greatest western elongation because it’s west of the Sun and rises before the Sun. From now until its superior conjunction next year, on June 4th. It will move closer and closer to the Sun from our vantage point. But it’s just moving around behind the Sun. The Mayans at the peak of their civilization were diligent observers of Venus. They found the Venus cycle, what we would call synodic period of Venus of 584 days, from the heliacal rising of Venus, its first appearance in the morning sky after disappearing in the evening, to the next heliacal rising. Venus would reach its greatest elongation from the Sun about 66 days after its heliacal rising.

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

Venus at 7:15 this morning, October 23, 2023. It will be in pretty much the same position tomorrow morning, less than a day from its greatest western elongation. Also shown is its orbit as seen from the Earth. Created using Stellarium.
The Venus Cycle or synodic period of 584 days broken into morning and evening appearances as the Mayans saw it. The grayed area is the part of the cycle when Venus is too close to the Sun to be seen with the naked eye under the most ideal conditions. Venus will be in the morning sky until June 4th of next year. It will be visible until early May as the Morning Star. Credit: the author.

Ephemeris Extra: Star Party Tomorrow night, 10/21/2023, if it’s clear

October 20, 2023 Comments off

Update: 10/21/2023 The Star Party has been canceled due to weather (clouds)

This was the last planned star party at the Sleeping Bear Dunes this year. Look for star parties in 2024. Also, there will be a star party after the Grand Traverse Astronomical Society meetings, November 3rd and December 1st, of course weather permitting, at Northwestern Michigan College’s Joseph H. Rogers Observatory. The observatory is located south of Traverse City on Birmley Road. Meetings start at 8 pm, and are not weather dependent, with observing after (approximately 9 pm) if it’s clear. Topic of the meeting programs: November: A documentary video Jack Newton’s Journey to the Stars. Jack Newton (1942-) is a Canadian amateur astronomer and pioneering astrophotographer. December: Ancient Greek astronomy.

Original Post Below

Sleeping Bear Dunes 40th anniversary cake lighting
Sleeping Bear Dunes 40th anniversary cake lighting on at the Stop 3, Pierce Stocking Scenic Drive (Dunes Overlook) October 21, 2010. This was the GTAS second star party with the park in the society’s over 13 year collaboration with the Sleeping Bear Dunes National Lakeshore. I don’t know if there will be a cake this time, but all those candles are not conducive to keeping one’s night vision. We since had to move the star parties to the Dive Climb to accommodate the larger crowds that have built up since. Credit: Eileen Carlisle.

Members of the Grand Traverse Astronomical Society will team up with the park rangers of the Sleeping Bear Dunes National Lakeshore for the last star party of the year celebrating the park’s 53rd anniversary. It will take place at the Dune Climb. Of course, it will only occur if it is clear or partly cloudy. It starts at 4 pm with solar observing using personal and the society’s solar telescopes. Starting at 7 pm it will be dark enough to view the first quarter Moon, followed a bit later with Saturn, and still later with Jupiter. The brighter wonders beyond the solar system will be also be visible later.

Ephemeris: 10/20/2023 – Halley’s Comet is back! Sort of.

October 20, 2023 Comments off

This is Ephemeris for Friday, October 20th. Today the Sun will be up for 10 hours and 45 minutes, setting at 6:50, and it will rise tomorrow at 8:05. The Moon, 1 day before first quarter, will set at 10:42 this evening.

Halley’s Comet is back! (Pronounced Hall-ey’s) Well sorta. In the form of the Orionid meteor shower. Bits of Halley’s Comet from previous passes by the Earth’s orbit make their twice-yearly show in our skies as these bits collide with the Earth’s atmosphere. Halley’s orbit passes close to the earth’s orbit at points where the Earth is around May 6th and again near October 21st. Light dust and ionized gas get blown back into the tail of the comet. Heavier particles, still affected by the pressure of sunlight and the gravitational pull of the Sun and planets end up roughly following the comet’s orbit. In the morning after the Moon sets (11:55 pm on the 21st) should be the best time to see them. They will seem to come from a spot above Orion and below Gemini.

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

Sky Dome for the Orionids based on the sky at 2 am, October 22, 2023. The radiant for the Orionids is marked with yellow streaks with the label OriR near Orion’s upraised arm holding a club above Betelgeuse in the east. Click or tap on the image to enlarge it. Created using my LookingUp app.

Ephemeris: 10/19/2023 – The southern star of autumn – Fomalhaut

October 19, 2023 Comments off

This is Bob Moler with Ephemeris for Thursday, October 19th. Today the Sun will be up for 10 hours and 48 minutes, setting at 6:51, and it will rise tomorrow at 8:04. The Moon, 2 days before first quarter, will set at 9:39 this evening.

There’s a bright star that appears for only seven and a half hours on autumn evenings. Its appearance, low in the south-southeast at 9 p.m., is a clear indication of the autumn season. It is currently below the much brighter Saturn. The star’s name is Fomalhaut, which means fish’s mouth. That’s fitting because it’s in the constellation of Piscis Austrinus, the southern fish. At our latitude it’s kind of the fish that got away, because usually Fomalhaut appears to be quite alone low in the sky. For the last few years Jupiter and then Saturn have kept it company. In a couple of years Saturn will have moved on leaving Fomalhaut to its lonely vigil in the south.

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

The first magnitude star Fomalhaut transits, that it is due south at 10:49 this evening, October 19, 2023. The brighter Saturn is above and Fomalhaut is below. The word Fomalhaut means “fishes mouth” and as you can see the Stellarium artist did indeed draw the fish, so Fomalhaut is where the fish’s mouth is in the constellation of Piscis Austrinus or the southern fish. I’ve added the constellations of the Zodiac with it. Click or tap on the image to enlarge it. Created using Stellarium, LibreOffice Draw, and GIMP.