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Ephemeris: 11/10/2025 – Waiting on a stellar explosion

November 10, 2025 Comments off

This is Ephemeris for Monday, November 10th. Today the Sun will be up for 9 hours and 46 minutes, setting at 5:19, and it will rise tomorrow at 7:34. The Moon, 2 days before last quarter, will rise at 10:22 this evening.

According to one astronomer, that I mentioned last Thursday, today is about the day he expects a star to erupt as a nova in the constellation Corona Borealis, the Northern Crown. In the early evening, it will appear low in the west northwest. The star is designated T Coronae Borealis (T CrB). Its appearance should make the normal news outlets, because it will be the brightest stellar outburst in a very long time. It will appear just left of the constellation Corona Borealis and be about as bright as its brightest normal star. However, it will soon fade and to be less the naked eye brightness in about a week. So we’re hoping for clear skies, if it happens. If it’s not this time, the next predicted time is June 25th, next year. Or he could be wrong, and it could go off at any time. Spaceweather.com has more information.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

If T CrB goes nova around November 10, 2025, this would be the location of the nova in the sky at 7 PM for the Grand Traverse area of Michigan.
If T CrB goes nova around November 10, 2025, this would be the location of the nova in the sky at 7 PM for the Grand Traverse area of Michigan. This is about an hour and 20 minutes after sunset for most northern mid-latitude locations. Created using Stellarium, labeled in LibreOffice Draw and exported in GIMP.

According to a paper in the Research Notes of the American Astronomical Society, Jean Schneider with the Paris Observatory predicted that the next eruption of T Coronae Borealis would be somewhere around November 10th 2025, or June 25th 2026. The first prediction of the 27th of March earlier this year turned out to not have occurred. These were tentative predictions based on the orbit around each other, of the two stars involved. The period of 80 years between eruptions is an approximation. There is an additional periodicity due to the fact that the two stars involved, a red giant and a white dwarf, have an orbital period of about 228 days which is why the predictions are 228 days apart. There have been four previous eruptions of the star observed. The first was in 1217, the next in 1787, then in 1866 and then finally in 1946. The reason for the big gap between 1217 and 1787 is unknown. Either the star didn’t erupt, or more likely, nobody observed and recorded it. The times of the first two eruptions weren’t accurately reports, but fell within what the 228-day periodicity would explain.

T Coronae Borealis is far enough north in the sky so that it is visible sometime during the night, year round. Currently, it would be best seen at the end of twilight in the west northwest. This will shift over to the morning sky, before morning twilight, after about the 25th of November, only 15 days from now in the east northeast. This star like any other star that rises and sets does so approximately 4 minutes earlier each night, or 28 minutes per week. So after the 25th the best observing opportunity will be before dawn in the morning until much later in the late winter, when it will be available also in the evening sky again.

Categories: Ephemeris Program, Nova, Observing, Stars Tags: ,

Ephemeris: 11/07/25 – GTAS meeting tonight, topic is Fighting Light Pollution

November 7, 2025 Comments off

This is Ephemeris for Friday, November 7th. Today the Sun will be up for 9 hours and 53 minutes, setting at 5:23, and it will rise tomorrow at 7:30. The Moon, 2 days past full, will rise at 6:43 this evening.

The Grand Traverse Astronomical Society will hold a special meeting and program at 7 PM tonight, a special time, at Northwestern Michigan College’s Rogers Observatory. Dr. Jerry Dobek, astronomy professor at NMC, will present an illustrated talk on Light Pollution. The focus of the talk will be on the general causes and effects of light pollution, as well as examples of proper lighting. Dr. Dobek has helped write lighting ordinances for governments here and around the nation. A star party will start around 8 pm, but only if it’s clear. The observatory is located south of Traverse City, on Birmley Road. The meeting is also available via Zoom. A link can be found on the society’s website, gtastro.org.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

A Satellite View Lights of the United States at Night.
A Satellite View Lights of the United States at Night. Credit: NASA/Goddard Space Flight Center

Categories: Ephemeris Program, GTAS Outreach Event Tags: , ,

Ephemeris: 11/06/2025 – An astronomer thinks a nova will appear soon

November 6, 2025 Comments off

This is Ephemeris for Thursday, November 6th. Today the Sun will be up for 9 hours and 56 minutes, setting at 5:24, and it will rise tomorrow at 7:29. The Moon, 1 day past full, will rise at 5:50 this evening.

We’ve been waiting for the past year or so for the eruption of a nova in the constellation Corona Borealis the Northern Crown. It last erupted in 1946. Eruptions are about 80 years apart. Astronomer Jean Schneider of the Paris Observatory has made a study of this particular nova. It occurs in a binary star system with a white dwarf and a much larger star that orbit each other every 228 days. So it is possible that the Nova occurs at one point in that orbit. And based on the last eruption in 1946, November 10th, give or take, is one of the days we might look to see the eruption. If it doesn’t happen that day its next likely occurrence is around June 25th next year. It will appear just left of Corona Borealis low in the west northwest around 7 PM, and as bright as the normally brightest star in that constellation.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

If T CrB goes nova around November 10, 2025, this would be the location of the nova in the sky at 7 PM for the Grand Traverse area if Michigan.
If T CrB goes nova around November 10, 2025, this would be the location of the nova in the sky at 7 PM for the Grand Traverse area if Michigan. This is about an hour and 20 minutes after sunset for most northern mid-latitude locations. Created using Stellarium, labeled in LibreOffice Draw and exported in GIMP.

The website Spaceweather.com monitors reports of the brightness of the star on the right side of its page under the heading of T CrB NOVA WATCH. It is currently around 10th magnitude, invisible to the naked eye and barely visible in binoculars. It is expected to grow to 2nd magnitude or 1,600 times it’s normal brightness, about as bright as a Big Dipper star or Alphecca, near it, in Corona Borealis. The nova will fade rapidly, and will be visible to the naked eye for only about a week.

Categories: Ephemeris Program, Nova, Observing Tags: , ,

Ephemeris: 11/05/2025 – Taking our weekly look at the whereabouts of the naked-eye planets

November 5, 2025 Comments off

This is Ephemeris for Wednesday, November 5th. Today the Sun will be up for 9 hours and 59 minutes, setting at 5:25, and it will rise tomorrow at 7:28. The Hunter’s Full Moon today, will rise at 5:10 this evening.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Saturn is the brightest star like object in the east southeastern sky as soon as it gets dark. In a telescope Saturn sports a very thin ring, half of a degree from being edge on in telescopes. Many times I’ve been asked whether they can see Saturn’s rings in their telescope. Normally I’d say yes. Currently, the rings appear extremely thin and can be difficult to pick up. Jupiter will rise at 9:58 PM in the east-northeast. By 6:30 AM, it will appear high in the south-southeast, below the stars of Gemini, with Orion and the other bright stars of winter in the southwest. Brilliant Venus, which will rise at 6:04 AM will be very low in the east-southeast at 6:30.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Saturn in the east south southeast with the full Moon in the east at 8 PM tonight.
Saturn in the east south southeast with the full Moon in the east at 8 PM tonight, November 5, 2025. Created using Stellarium.
The full Moon tonight, November 5, 2025. A view visible in small telescopes showing an image with and without selected features labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
Venus will be visible very low in the east-southeast, and Jupiter will be high in the south southwestern sky among the winter stars at 6:30 AM tomorrow morning.
Venus will be visible very low in the east-southeast, and Jupiter will be high in the south southwestern sky among the winter stars at 6:30 AM tomorrow morning, November 6, 2025. Created using Stellarium.
Telescopic Saturn, Jupiter and Venus (north up) as they would be seen in a small telescope with the same magnification.
Telescopic Saturn, Jupiter and Venus (north up) as they would be seen in a small telescope with the same magnification. On the evening of the November 5, 2025, Saturn will be 18.8″ in diameter, but its rings, being nearly edge on, may show up brighter than seen here, and extend to 43.8″. They are tilted 0.5° from being edge on. At 6:30 AM on the morning of November 6, 2025, Jupiter will be 41.2″ in diameter. Venus’ apparent diameter will be 10.2″, and be 96.7% illuminated. It’s on the far side of the Sun. The (”) symbol means seconds of arc, or 1/3600th of a degree. Created using Cartes du Ciel (Sky Charts), LibreOffice Draw and GIMP.
The naked-eye planets and the Moon at sunset and sunrise on a single night.
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on November 5th, 2025. The night ends on the left with sunrise on the 6th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
A low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow
This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, November 5th and 6th, 2025. Some of the columns are self-explanatory, others are not. The transit column is the time that the body crosses the meridian and is due south. Elong, for elongation, is the angle between the Sun and that body. RA is right ascension, which is the object’s east-west position on the celestial sphere in hours and minutes. Dec is declination which is the north-south position of the object on the celestial sphere in degrees and minutes. R is the distance of that object from the Sun in astronomical units. An astronomical unit is about 93 million miles or 150 million kilometers. And Delta is the distance of that object from the Earth, also in astronomical units. I omit the ‘m’ in am and pm for compactness. The data was generated using my LookingUp for DOS app and displayed as a table by my Ephemeris Helper app.
Categories: Ephemeris Program, Naked-eye planets, Observing Tags: , , , , ,

Ephemeris: 11/04/2025 – The Persephone Period starts tomorrow

November 4, 2025 Comments off

This is Bob Moler with Ephemeris for Election Day for some, Tuesday, November 4th. Today the Sun will be up for 10 hours and 1 minute, setting at 5:26, and it will rise tomorrow at 7:26. The Moon, 1 day before full, will set at 7:41 tomorrow morning.

Tomorrow the daylight hours drops below 10 hours. This begins something which has been called the Persephone Period. It is named after the Greek goddess Persephone, goddess of spring, who is abducted by Hades the god of the underworld to be his bride. When he did, all the vegetation on the earth began to die. So he had to allow her to appear above ground for a part of the year so that the vegetation and the grain would grow. So the Persephone Period is the time when she is in the underworld. It lasts from now to early February. That may have worked for a country like Greece around the Mediterranean, but we have harsher weather here. It takes a much longer time for spring to arrive.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

One of the many sculptures of Persephone and Hades.
One of the many sculptures of Persephone and Hades. Uncredited.

Categories: Ephemeris Program, Mythology, Seasons Tags:

Ephemeris: 11/03/2025 – Why is the universal expansion speeding up?

November 3, 2025 Comments off

This is Ephemeris for Monday, November 3rd. Today the Sun will be up for 10 hours and 4 minutes, setting at 5:28, and it will rise tomorrow at 7:25. The Moon, 2 days before full, will set at 6:15 tomorrow morning.

The Big Bang, nearly 14 billion years ago set the universe to be expanding. All the mass of ordinary matter and the dark matter I talked about last week should be slowing that expansion. However, about 20 years ago it was discovered that the universal expansion is not slowing down. Instead, the expansion rate is increasing! Astronomers don’t really know why. Since expansion requires energy, this new property is called dark energy. It is actually the expansion of space itself. The galaxies are not fleeing by their own motion through space. They are carried by the expanding space around them. It turns out that objects with mass cannot exceed the speed of light, but the expansion of space itself has no speed limit. At least that’s how I understand it.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

This is an infographic of the evolution and expansion of the universe from the Big Bang to the present day.
This is an infographic of the evolution and expansion of the universe from the Big Bang to the present day showing the inflationary period when it increased in size extremely rapidly, faster than the speed of light, actually. About 380,000 years later light was finally decoupled from matter. Before then the universe was opaque. Light could not travel very far before hitting another particle. At 380,000 years the universe became cool enough so that electrons and protons in this Big Bang soup could find each other and become atoms. This caused the universe to become transparent. At that point is where we see, with our radio telescopes, the cosmic microwave background radiation. After that there’s a period where stars are being formed. There’s not much light being emitted because the stars are not radiating brightly because the hydrogen fusion in their cores had not started. This period is called the dark ages and may have lasted up to 400 million years. The period of the first stars and galaxies is the area that James Webb Space Telescope was primarily built to investigate. It is only visible in the infrared. All this happened 9 billion years before the Earth was formed. It is evolution on a scale Darwin could not have imagined! Click or tap on the image to enlarge it. Credit: NASA

Categories: Cosmology, Dark energy, Ephemeris Program

Ephemeris: 10/31/2025 – Previewing November skies

October 31, 2025 Comments off

This is Ephemeris for Halloween, Friday, October 31st. Today the Sun will be up for 10 hours and 12 minutes, setting at 6:32, and it will rise tomorrow at 8:21. The Moon, 2 days past first quarter, will set at 3:17 tomorrow morning.

Let’s look ahead at the skies for the month of November. The Sun is still moving south rapidly at the beginning of the month, but will slow down toward the end. Daylight hours in the Interlochen/Traverse City area and will drop from 10 hours and 9 minutes tomorrow to 9 hours 4 minutes on the 30th. The altitude, or angle, of the Sun above the southern horizon at local noon will be at 30 degrees tomorrow and will descend to 23 and a half degrees on the 30th. The altitude of the Sun in the Straits area will be a degree lower. Local noon, next month, is about 12:30 p.m. This Sunday we fall back one hour to Standard Time, making our mornings a bit lighter, and our early evenings a bit darker.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

November Evening Star Chart

Star Chart for November evenings, 2025 (9 pm EST November 15, 2025).
Star Chart for November evenings, 2025 (9 pm EST November 15, 2025).
Jupiter is close to rising in the east-northeast at chart time. Click on the image to enlarge it. Created using my LookingUp app.

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.

November Morning Star Chart

Star Chart for November mornings, 2025 (6 a.m. EST November 16, 2025).
Star Chart for November mornings, 2025 (6 a.m. EST November 16, 2025). Click on the image to enlarge it. Created using my LookingUp app.

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 in 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 in the morning star chart is the radiant of the Leonid meteor shower, which peaks on the morning of the 17th.

Twilight Limits, Nautical and Astronomical

      EDT        
  Morning Twilight Evening Twilight Dark Night Moon
Date Astro. Nautical Nautical Astro. Start End Illum.
2025-11-01 6h44m 7h17m 19h35m 20h13m 3h18m 6h44m 0.85
      EST        
2025-11-02 5h45m 6h19m 18h34m 19h12m 3h34m 5h45m 0.92
2025-11-03 5h46m 6h20m 18h33m 19h11m 4h53m 5h46m 0.97
2025-11-04 5h47m 6h21m 18h32m 19h09m – – 1.00
2025-11-05 5h48m 6h22m 18h30m 19h08m – – 0.99
2025-11-06 5h49m 6h23m 18h29m 19h07m – – 0.96
2025-11-07 5h51m 6h25m 18h28m 19h06m – – 0.90
2025-11-08 5h52m 6h26m 18h27m 19h05m 19h05m 19h49m 0.81
2025-11-09 5h53m 6h27m 18h26m 19h04m 19h04m 21h05m 0.72
2025-11-10 5h54m 6h28m 18h25m 19h03m 19h03m 22h22m 0.61
2025-11-11 5h55m 6h29m 18h24m 19h02m 19h02m 23h37m 0.50
2025-11-12 5h56m 6h31m 18h23m 19h01m 19h01m – 0.40
2025-11-13 5h58m 6h32m 18h22m 19h01m 19h01m 0h49m 0.30
2025-11-14 5h59m 6h33m 18h21m 18h56m 18h56m 1h57m 0.22
2025-11-15 6h00m 6h34m 18h21m 18h55m 18h55m 3h02m 0.14
2025-11-16 6h01m 6h35m 18h20m 18h54m 18h54m 4h07m 0.08
2025-11-17 6h02m 6h37m 18h19m 18h53m 18h53m 5h11m 0.04
2025-11-18 6h03m 6h38m 18h18m 18h53m 18h53m 6h03m 0.01
2025-11-19 6h04m 6h39m 18h18m 18h52m 18h52m 6h04m 0.00
2025-11-20 6h05m 6h40m 18h17m 18h51m 18h51m 6h05m 0.01
2025-11-21 6h07m 6h41m 18h16m 18h51m 18h51m 6h07m 0.03
2025-11-22 6h08m 6h42m 18h16m 18h50m 18h50m 6h08m 0.08
2025-11-23 6h09m 6h43m 18h15m 18h50m 19h24m 6h09m 0.13
2025-11-24 6h10m 6h45m 18h15m 18h49m 20h30m 6h10m 0.21
2025-11-25 6h11m 6h46m 18h14m 18h49m 21h39m 6h11m 0.29
2025-11-26 6h12m 6h47m 18h14m 18h49m 22h49m 6h12m 0.39
2025-11-27 6h13m 6h48m 18h13m 18h48m – 6h13m 0.49
2025-11-28 6h14m 6h49m 18h13m 18h48m 0h00m 6h14m 0.60
2025-11-29 6h15m 6h50m 18h13m 18h48m 1h13m 6h15m 0.71
2025-11-30 6h16m 6h51m 18h12m 18h47m 2h27m 6h16m 0.80

 

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  Sa            Venus: 16.2° W
     1  Sa  12:46 PM  Moon Ascending Node
     1  Sa   8:04 PM  Venus-Spica: 3.5° N
     2  Su   5:46 AM  Moon-Saturn: 3.7° S
     5  We   7:36 AM  South Taurid Shower: ZHR = 10
     5  We   8:19 AM  Full Moon, so-called Super Moon
     5  We   5:29 PM  Moon Perigee: 356800 km
     6  Th  10:26 AM  Moon-Pleiades: 0.8° S
     8  Sa   6:41 AM  Moon North Dec.: 28.4° N
     8  Sa   9:45 PM  Mercury-Antares: 3.6° N
    10  Mo   1:40 AM  Moon-Pollux: 2.7° N
    10  Mo   2:56 AM  Moon-Jupiter: 4° S
    11  Tu  12:27 AM  Moon-Beehive: 1.8° S
    12  We  12:28 AM  Last Quarter
    12  We   6:52 AM  North Taurid Shower: ZHR = 15
    12  We   5:51 PM  Moon-Regulus: 1.1° S
    12  We  10:41 PM  Mercury-Mars: 1.2° N
    14  Fr   1:38 AM  Moon Descending Node
    17  Mo   5:11 AM  Moon-Spica: 1.3° N
    17  Mo   1:10 PM  Leonid Shower: ZHR = 15
    19  We   9:48 PM  Moon Apogee: 406700 km
    20  Th   1:47 AM  New Moon
    20  Th   4:20 AM  Mercury Inferior Conj.
    21  Fr   7:33 AM  Uranus Opposition
    22  Sa   1:12 PM  Moon South Dec.: 28.3° S
    28  Fr   1:59 AM  First Quarter
    28  Fr   4:33 PM  Moon Ascending Node
    29  Sa   2:08 PM  Moon-Saturn: 3.8° S
Dec  1  Mo            Venus: 8.7° W

All event times for November 1 & 2 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, 2025    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Sat  1| 08:21a  06:30p  10:09 | 07:35p  07:16a |      Set  04:33a   83%|
+------+-----------------------+----------------+-----------------------+
| EST  |      Time Change      |                |                       |
|Sun  2| 07:22a  05:29p  10:07 | 06:34p  06:17a |      Set  04:52a   91%|
|Mon  3| 07:23a  05:28p  10:04 | 06:33p  06:18a |      Set  06:15a   96%|
|Tue  4| 07:25a  05:26p  10:01 | 06:32p  06:19a |      Set  07:41a   99%|
|Wed  5| 07:26a  05:25p  09:59 | 06:31p  06:21a |Full  Rise 05:10p  100%|
|Thu  6| 07:28a  05:24p  09:56 | 06:30p  06:22a |      Rise 05:50p   97%|
|Fri  7| 07:29a  05:23p  09:53 | 06:28p  06:23a |      Rise 06:43p   91%|
|Sat  8| 07:30a  05:21p  09:51 | 06:27p  06:24a |      Rise 07:49p   83%|
+------+-----------------------+----------------+-----------------------+
|Sun  9| 07:32a  05:20p  09:48 | 06:26p  06:25a |      Rise 09:04p   73%|
|Mon 10| 07:33a  05:19p  09:46 | 06:25p  06:27a |      Rise 10:22p   63%|
|Tue 11| 07:34a  05:18p  09:43 | 06:24p  06:28a |      Rise 11:37p   52%|
|Wed 12| 07:36a  05:17p  09:41 | 06:23p  06:29a |L Qtr Rise 12:48a   42%|
|Thu 13| 07:37a  05:16p  09:38 | 06:23p  06:30a |      Rise 01:56a   32%|
|Fri 14| 07:38a  05:15p  09:36 | 06:22p  06:31a |      Rise 03:02a   23%|
|Sat 15| 07:40a  05:14p  09:34 | 06:21p  06:33a |      Rise 04:06a   16%|
+------+-----------------------+----------------+-----------------------+
|Sun 16| 07:41a  05:13p  09:31 | 06:20p  06:34a |      Rise 05:11a    9%|
|Mon 17| 07:42a  05:12p  09:29 | 06:19p  06:35a |      Rise 06:16a    5%|
|Tue 18| 07:44a  05:11p  09:27 | 06:19p  06:36a |      Rise 07:22a    2%|
|Wed 19| 07:45a  05:10p  09:25 | 06:18p  06:37a |      Rise 08:28a    0%|
|Thu 20| 07:46a  05:09p  09:23 | 06:17p  06:38a |New   Set  04:56p    1%|
|Fri 21| 07:48a  05:09p  09:21 | 06:17p  06:40a |      Set  05:36p    3%|
|Sat 22| 07:49a  05:08p  09:18 | 06:16p  06:41a |      Set  06:26p    7%|
+------+-----------------------+----------------+-----------------------+
|Sun 23| 07:50a  05:07p  09:17 | 06:15p  06:42a |      Set  07:24p   12%|
|Mon 24| 07:51a  05:07p  09:15 | 06:15p  06:43a |      Set  08:29p   19%|
|Tue 25| 07:53a  05:06p  09:13 | 06:14p  06:44a |      Set  09:38p   27%|
|Wed 26| 07:54a  05:05p  09:11 | 06:14p  06:45a |      Set  10:49p   37%|
|Thu 27| 07:55a  05:05p  09:09 | 06:14p  06:46a |      Set  12:00a   47%|
|Fri 28| 07:56a  05:04p  09:08 | 06:13p  06:47a |F Qtr Set  01:12a   58%|
|Sat 29| 07:57a  05:04p  09:06 | 06:13p  06:48a |      Set  02:26a   68%|
+------+-----------------------+----------------+-----------------------+
|Sun 30| 07:59a  05:03p  09:04 | 06:13p  06:49a |      Set  03:44a   78%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunset and sunrise

Generated using my LookingUp for DOS app.

Categories: Ephemeris Program, Month preview Tags:

Ephemeris: 10/30/2025 – Algol, the perfect Halloween star

October 30, 2025 Comments off

This is Ephemeris for Thursday, October 30th. Today the Sun will be up for 10 hours and 15 minutes, setting at 6:33, and it will rise tomorrow at 8:19. The Moon, 1 day past first quarter, will set at 2:03 tomorrow morning.

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 we knew what was wrong with it. 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. Tuesday, November 4th.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

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.
Eclipsing Binary Star
Animation of an eclipsing binary star like Algol. Credit: Wikimedia Commons h/t Earth and Sky
Categories: Ephemeris Program, Observing, Stars Tags: , ,

Ephemeris: 10/29/2025 – Looking at the whereabouts of the naked-eye planets for this week

October 29, 2025 Comments off

This is Ephemeris for Wednesday, October 29th. Today the Sun will be up for 10 hours and 18 minutes, setting at 6:35, and it will rise tomorrow at 8:18. The Moon, at first quarter today, will set at 12:50 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Saturn is the brightest star like object in the east southeastern sky as soon as it gets dark. In a telescope Saturn sports a very thin ring, six tenths of a degree from being edge on in telescopes. Many times I’ve been asked whether they can see Saturn’s rings in their telescope. Normally I’d say yes. Currently, the rings appear extremely thin and can be difficult to pick up. Jupiter will rise before midnight at 11:17 PM. By 7:30 AM, it will appear high in the south-southeast, below the stars of Gemini, with Orion and the other bright stars of winter in the southwest. Brilliant Venus, which will rise at 6:48 AM will be very low in the east-southeast at 7:30 AM.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

Saturn with Fomalhaut and the Moon tonight at 9:00 PM, October 29, 2025.
Saturn with Fomalhaut and the Moon tonight at 9:00 PM, October 29, 2025. Created using Stellarium.
The first quarter Moon tonight, October 29, 2025. A view visible in small telescopes showing an image with and without selected features labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
Venus and Jupiter are visible in the east and southern sky among the winter stars at 7:30 AM tomorrow morning, October 30, 2025.
Venus and Jupiter are visible in the east and southern sky among the winter stars at 7:30 AM tomorrow morning, October 30, 2025. Created using Stellarium.
Telescopic Saturn, Jupiter and Venus
Telescopic Saturn, Jupiter and Venus (north up) as they would be seen in a small telescope with the same magnification. On the evening of the October 29, 2025, Saturn will be 19.0″ in diameter, but its rings, being nearly edge on, may not be visible at all though they extend to 44.2″, they are tilted 0.7° from being edge on. Titan is transiting the planet at that time. At 6 AM on the morning of October 30, 2025, Jupiter will be 40.4″ in diameter. At 7:30 AM, Venus’ apparent diameter will be 10.5″, and be 95.9% illuminated. It’s on the far side of the Sun. The (”) symbol means seconds of arc, or 1/3600th of a degree. Created using Cartes du Ciel (Sky Charts), LibreOffice Draw and GIMP.
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on October 29th, 2025. The night ends on the left with sunrise on the 30th.
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on October 29th, 2025. The night ends on the left with sunrise on the 30th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
A low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, October 29th and 30th, 2025.
This is a low precision ephemeris of the Sun Moon and naked eye planet positions for today and tomorrow, October 29th and 30th, 2025. Some of the columns are self-explanatory, others are not. The transit column is the time that the body crosses the meridian and is due south. Elong, for elongation, is the angle between the Sun and that body. RA is right ascension, which is the object’s east-west position on the celestial sphere in hours and minutes. Dec is declination which is the north-south position of the object on the celestial sphere in degrees and minutes. R is the distance of that object from the Sun in astronomical units. An astronomical unit is about 93 million miles or 150 million kilometers. And Delta is the distance of that object from the Earth, also in astronomical units. I omit the ‘m’ in am and pm for compactness. The data was generated using my LookingUp for DOS app and displayed as a table by my Ephemeris Helper app.

Categories: Ephemeris Program, Naked-eye planets, Observing Tags: , , , , ,

Ephemeris: 10/28/2025 – The structure of the universe

October 28, 2025 Comments off

This is Ephemeris for Tuesday, October 28th. Today the Sun will be up for 10 hours and 20 minutes, setting at 6:36, and it will rise tomorrow at 8:17. The Moon, 1 day before first quarter, will set at 11:38 this evening.

Dark matter makes up about 85% of all the matter in the universe, even though we can’t see it. It creates a kind of lattice on which the galaxies form. In looking out into the universe we see that there is a structure to it, not just random clusters of galaxies. The structure of the universe seems to be like a foam of bubbles where galaxies form along the intersection of these bubbles. The bubbles themselves are called voids. And with the expansion of the universe these voids are growing because space itself is expanding. So it’s not so much that the galaxies are fleeing each other, but that the voids are growing, pushing the galaxies apart. The galaxies are just going along for the ride.

The astronomical event times given in this blog are for the Traverse City/Interlochen area of Michigan (Lat 44.7° N, Long 85.7° W; EDT, UT – 4 hours) unless stated otherwise. Times will be different for other locations.

Addendum

The plot shows that the galaxies are not uniformly distributed in space. They are seen to form along filaments
This is the 2 Micron All Sky Survey (2MASS) which is an infrared survey of galaxies relatively close to us in an equal area projection. Each of the 30 by 30° squares has the same area. The horizontal dark area in the center it’s called the zone of avoidance, that is where the Milky Way is blocking the galaxies behind it, due to its clouds of gas and dust. The plot shows that the galaxies are not uniformly distributed in space. They are seen to form along filaments. The plot is also color-coded from violet to red showing the red shift, which shows the galaxy’s speed of recession, and increased distance. Click or tap on the image to enlarge it.

Categories: Cosmology, Ephemeris Program, Galaxies, Universe