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Ephemeris: 09/06/2024 – Grand Traverse Astronomical Meeting Tonight

September 6, 2024 Comments off

This is Bob Moler with Ephemeris for Friday, September 6th. Today the Sun will be up for 12 hours and 57 minutes, setting at 8:09, and it will rise tomorrow at 7:12. The Moon, 4 days past new, will set at 9:26 this evening.

The Grand Traverse Astronomical Society will host its September meeting tonight at 8:00 PM at Northwestern Michigan College’s Joseph H Rogers Observatory, which is located on Birmley Rd. South of Traverse City between Garfield and Keystone roads. The program topic will be a surprise, at least to me. After the meeting about 9:00 PM if it’s clear there will be viewing of the heavens through the observatory’s telescopes, featuring possibly the Moon and Saturn, the first of which may be too low or be obstructed, and when it’s darker the wonders of the Milky Way will be visible including nebulae, open star clusters, and my favorite globular star clusters, spherical masses of hundreds of thousands of stars, as old as the Milky Way itself.

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

Telescopes setup behind the observatory for a star party
The Joseph H Rogers Observatory with dome in the background, and a small Dome set out back plus some of the society member’s telescopes set up for a star party. Photograph by the author.
Categories: Ephemeris Program, GTAS Outreach Event, Star Party Tags: , , ,

Ephemeris: 09/04/2024 – Where are the naked-eye planets this week?

September 4, 2024 Comments off

This is Ephemeris for Wednesday, September 4th. Today the Sun will be up for 13 hours and 3 minutes, setting at 8:12, and it will rise tomorrow at 7:10. The Moon, 2 days past new, will set at 8:53 this evening.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus might be glimpsed low in the west around 8:30 PM. It will set at 9:08. It is best seen over a very low or lake horizon. The thin sliver of the Moon might be seen below and to the right. Saturn will rise shortly after sunset, and by 9 PM will be low in the east-southeast, pretty much by itself. Saturn may look disappointing in telescopes this year since its rings are nearly edge on and appearing as a line through the planet. Jupiter and Mars will be up in the east in the morning, and by 6 am tomorrow, Jupiter will be the brightest starlike object in the sky among the winter stars. Mars will be just below it to the left. Mercury might be spotted near the horizon in the east, now and for the next week.

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

Venus and the Moon in evening twilight, approximately 20 minutes after sunset
Venus and the Moon in evening twilight, approximately 20 minutes after sunset. For the Grand Traverse area of Michigan that woud be about 8:30 PM, where Venus would be about 6 1/2 degrees above the horizon and the Moon 3 1/2 degrees. They would be higher from the south of us, below 45° N latitude, and lower for those north of us. Created using Stellarium.
Moon as it might be seen in the small telescope or binoculars at 8:30 PM
This is the Moon as it might be seen in the small telescope or binoculars at 8:30 PM tonight, September 4th 2024. It will be very low and difficult to spot. Also it might be exhibiting earthshine as seen here in this image. Created using Stellarium.
Saturn as it would appear at 10 PM low in east southeast with the naked eye
Saturn as it would appear at 10 PM low in east southeast with the naked eye. It would seem to be pretty much alone in that sector of the sky of dim stars. Saturn will be in opposition to the Sun in three days, on Saturday evening. After which it will officially become an evening planet. Created using Stellarium.
An animated morning planet finder for 6:00 AM or about an hour before sunrise
An animated morning planet finder for 6:00 AM or about an hour before sunrise. Three frames: The first shows the sky as it may appear in the east southeast with no labels. The second frame labels the bright stars and planets. The third frame shows the planets and the constellation outlines. Created using Stellarium and GIMP.
Telescopic Venus, Saturn and Jupiter
Telescopic Venus, Saturn and Jupiter (north up) as they would be seen in a small telescope with the same magnification. Venus and Saturn are from the evening of the 4th, Jupiter is for 6 am on the 29th. Apparent diameters: Venus 11.1″, 90.4% illuminated; Saturn 19.2″, its rings 44.7″, 3.7 degrees from edge on (opening up a bit); Jupiter 37.0″; Mars, too small to be represented here, is 6.7″. Mercury, also too small 7.2″ and 46.6% illuminated. The ” means seconds of arc, or 1/3600th of a degree. Click or tap on the image to enlarge it. Created using Cartes du Ciel (Sky Charts).
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on September 4th, 2024. The night ends on the left with sunrise on the 5th
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on September 4th, 2024. The night ends on the left with sunrise on the 5th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
This is 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, September 4 and 5 2024. Some of the columns are self-explanatory, others 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, Planets Tags: , , , , ,

Ephemeris: 09/03/2024 – The constellation of Scutum the shield

September 3, 2024 Comments off

This is Ephemeris for Tuesday, September 3rd. Today the Sun will be up for 13 hours and 6 minutes, setting at 8:14, and it will rise tomorrow at 7:09. The Moon, 1 day past new, will set at 8:38 this evening.

In the southern sky between the Teapot of Sagittarius below and Aquila the Eagle above, with Altair the southernmost star of the Summer Triangle, lies Scutum the shield of John Sobieski the Polish king who stopped the advance of the Turks at Kahlenberg, which lies on a hill overlooking Vienna, in 1683. The Polish half of me is very proud. Scutum is one of two official constellations which are related to real persons. The other one is Coma Berenices, a hank of Egyptian Queen Berenice’s hair. It’s recent as constellations go, to fill up a section of the sky that the ancients couldn’t make out anything, because the stars here are so dim and embedded in the glow of the Milky Way as to be nearly impossible to discern. Scutum lies in one of the richest portions of the Milky Way, wonderful to scan with binoculars and telescopes.

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

Scutum’s stars are faint, so to me it’s just an area of the Milky Way between Aquila above and Sagittarius with it’s Teapot below. Seen looking south at 10 pm September in early September. Created using Stellarium and GIMP.
The constellation Scutum, seen here as Scutum Sobiescian
The constellation Scutum, seen here as Scutum Sobiescian or Sobieski’s Shield), was invented by Johannes Hevelius and added to his 1690 Uranometria. Back in those days star charts were generally mirror images of the sky, because they were plotted first on a celestial globe. Thus seeing the sky from the outside, hence the mirror image. Later star maps were printed correctly as seen from the inside of the celestial globe. Of the constellations shown, Antinous didn’t survive to the present day. He also had Aquila the eagle flying to the southeast, rather than how it is depicted today, flying northeastward.
The constellation Scutum seen on a modern map
The constellation Scutum seen on a modern map with its constellation boundaries. Credit International Astronomical Union & Sky and Telescope magazine.
Commemorative plaque featuring Sobiesk
Commemorative plaque featuring Sobieski in Vienna. Credit: Wikipedia User: Pi3.124
Categories: Constellations, Ephemeris Program, History Tags: , ,

Ephemeris: 09/02/2024 – Previewing September Skies

September 2, 2024 Comments off

This is Ephemeris for Labor Day, Monday, September 2nd. Today the Sun will be up for 13 hours and 9 minutes, setting at 8:16, and it will rise tomorrow at 7:08. The Moon is new today, and won’t be visible.

Let’s look at the skies for September. Daylight hours in the Interlochen/Traverse City area and will drop from 13 hours and 9 minutes today to 11 hours 43 minutes on the 30th. The altitude of the sun above the southern horizon at local noon will be 53 degrees today, and will descend to 42 degrees on the 30th. The official season of summer is getting short too, so enjoy it while you can. Summer will end and autumn will begin at 8:44 a.m. on the 22nd as the Sun will pass overhead at the equator heading southward. It will also mark sunset at the North Pole and sunrise at the South Pole. Southern Hemisphere dwellers will see the start of spring. The summer Milky Way is still visible to explore with binoculars or telescope.

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

September Evening Star Chart

September Evening Star Chart
Star Chart for September 2024 (10 pm September 15). Click or tap on the image to enlarge it. Created using my LookingUp program.

The planets and stars are plotted for the 15th at 10 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.

September Morning Star Chart

September Morning Star Chart
Star Chart for September 2024 (6 am EDT, September 15). 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.
  • 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.

Twilight Limits, Nautical and Astronomical

      EDT        
  Morning Twilight Evening Twilight Dark Night Moon
Date Astro. Nautical Nautical Astro. Start End Illum.
2024-09-01 5h23m 6h01m 21h28m 22h06m 22h06m 5h21m 0.01
2024-09-02 5h25m 6h02m 21h26m 22h04m 22h04m 5h25m 0.00
2024-09-03 5h26m 6h04m 21h24m 22h01m 22h01m 5h26m 0.01
2024-09-04 5h28m 6h05m 21h22m 21h59m 21h59m 5h28m 0.04
2024-09-05 5h29m 6h07m 21h20m 21h57m 21h57m 5h29m 0.09
2024-09-06 5h31m 6h08m 21h18m 21h55m 21h55m 5h31m 0.15
2024-09-07 5h32m 6h09m 21h16m 21h53m 21h53m 5h32m 0.22
2024-09-08 5h34m 6h11m 21h14m 21h50m 22h09m 5h34m 0.30
2024-09-09 5h35m 6h12m 21h12m 21h48m 22h39m 5h35m 0.40
2024-09-10 5h37m 6h13m 21h10m 21h46m 23h17m 5h37m 0.50
2024-09-11 5h38m 6h15m 21h08m 21h44m – 5h38m 0.60
2024-09-12 5h40m 6h16m 21h06m 21h42m 0h08m 5h40m 0.70
2024-09-13 5h41m 6h17m 21h04m 21h40m 1h12m 5h41m 0.80
2024-09-14 5h43m 6h18m 21h02m 21h37m 2h26m 5h43m 0.88
2024-09-15 5h44m 6h20m 21h00m 21h35m 3h47m 5h44m 0.95
2024-09-16 5h45m 6h21m 20h58m 21h33m 5h11m 5h45m 0.99
2024-09-17 5h47m 6h22m 20h56m 21h31m – – 1.00
2024-09-18 5h48m 6h24m 20h54m 21h29m – – 0.98
2024-09-19 5h50m 6h25m 20h52m 21h27m – – 0.94
2024-09-20 5h51m 6h26m 20h50m 21h25m – – 0.86
2024-09-21 5h52m 6h27m 20h48m 21h23m 21h23m 21h25m 0.77
2024-09-22 5h54m 6h29m 20h46m 21h21m 21h21m 22h03m 0.67
2024-09-23 5h55m 6h30m 20h44m 21h19m 21h19m 22h50m 0.56
2024-09-24 5h56m 6h31m 20h42m 21h17m 21h17m 23h48m 0.46
2024-09-25 5h58m 6h32m 20h40m 21h15m 21h15m – 0.35
2024-09-26 5h59m 6h34m 20h38m 21h13m 21h13m 0h53m 0.26
2024-09-27 6h00m 6h35m 20h36m 21h11m 21h11m 2h02m 0.18
2024-09-28 6h02m 6h36m 20h34m 21h09m 21h09m 3h12m 0.11
2024-09-29 6h03m 6h37m 20h32m 21h07m 21h07m 4h19m 0.06
2024-09-30 6h04m 6h39m 20h30m 21h05m 21h05m 5h24m 0.02

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

Sep  1  Su            Venus: 24.1° E
     2  Mo   9:55 pm  New Moon
     4  We   9:59 pm  Mercury Elongation: 18.1° W
     5  Th   1:43 am  Moon Descending Node
     5  Th   6:13 am  Moon-Venus: 1.3° N
     5  Th  10:55 am  Moon Apogee: 406200 km
     6  Fr  12:22 pm  Moon-Spica:  .6° S
     7  Sa  11:54 pm  Saturn Opposition
     8  Su  10:52 pm  Mercury-Regulus:  .4° N
    10  Tu   8:29 am  Moon-Antares:  .1° N
    11  We   2:06 am  First Quarter
    12  Th  12:51 am  Moon South Dec.: 28.7° S
    17  Tu   6:14 am  Moon-Saturn:  .3° S
    17  Tu  10:34 pm  Full Moon (Harvest Moon)
    17  Tu  10:45 pm  Partial Lunar Eclipse (See below)
    17  Tu  10:59 pm  Venus-Spica: 2.4° N
    18  We   9:26 am  Moon Perigee: 357300 km
    18  We   3:51 pm  Moon Ascending Node
    20  Fr   6:43 pm  Neptune Opposition
    22  Su   6:16 am  Moon-Pleiades:  .2° S
    22  Su   8:44 am  Autumnal Equinox
    24  Tu   1:04 pm  Moon North Dec.: 28.7° N
    24  Tu   2:50 pm  Last Quarter
    26  Th   6:25 am  Moon-Pollux: 1.8° N
    27  Fr   7:08 am  Moon-Beehive: 3.4° S
    30  Mo   4:59 pm  Mercury Superior Conj.
Oct  1  Tu            Venus: 31.4° 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), with modifications by the author.
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
September, 2024    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Sun  1| 07:05a  08:18p  13:12 | 09:24p  05:59a |      Rise 06:27a    1%|
|Mon  2| 07:07a  08:16p  13:09 | 09:22p  06:00a |New   Set  08:22p    0%|
|Tue  3| 07:08a  08:14p  13:06 | 09:20p  06:02a |      Set  08:38p    1%|
|Wed  4| 07:09a  08:12p  13:03 | 09:18p  06:03a |      Set  08:53p    3%|
|Thu  5| 07:10a  08:11p  13:00 | 09:16p  06:05a |      Set  09:09p    7%|
|Fri  6| 07:11a  08:09p  12:57 | 09:14p  06:06a |      Set  09:26p   13%|
|Sat  7| 07:12a  08:07p  12:54 | 09:12p  06:07a |      Set  09:45p   20%|
+------+-----------------------+----------------+-----------------------+
|Sun  8| 07:14a  08:05p  12:51 | 09:10p  06:09a |      Set  10:08p   28%|
|Mon  9| 07:15a  08:03p  12:48 | 09:08p  06:10a |      Set  10:38p   38%|
|Tue 10| 07:16a  08:01p  12:45 | 09:06p  06:11a |      Set  11:17p   47%|
|Wed 11| 07:17a  07:59p  12:42 | 09:04p  06:13a |F Qtr Set  12:07a   58%|
|Thu 12| 07:18a  07:58p  12:39 | 09:02p  06:14a |      Set  01:11a   68%|
|Fri 13| 07:19a  07:56p  12:36 | 09:00p  06:15a |      Set  02:25a   78%|
|Sat 14| 07:21a  07:54p  12:33 | 08:58p  06:16a |      Set  03:47a   86%|
+------+-----------------------+----------------+-----------------------+
|Sun 15| 07:22a  07:52p  12:30 | 08:56p  06:18a |      Set  05:10a   93%|
|Mon 16| 07:23a  07:50p  12:26 | 08:54p  06:19a |      Set  06:34a   98%|
|Tue 17| 07:24a  07:48p  12:23 | 08:52p  06:20a |Full  Rise 07:47p  100%|
|Wed 18| 07:25a  07:46p  12:20 | 08:50p  06:22a |      Rise 08:08p   99%|
|Thu 19| 07:27a  07:44p  12:17 | 08:48p  06:23a |      Rise 08:30p   95%|
|Fri 20| 07:28a  07:42p  12:14 | 08:46p  06:24a |      Rise 08:55p   88%|
|Sat 21| 07:29a  07:41p  12:11 | 08:44p  06:25a |      Rise 09:25p   79%|
+------+-----------------------+----------------+-----------------------+
|Sun 22| 07:30a  07:39p  12:08 | 08:42p  06:27a |      Rise 10:02p   69%|
|Mon 23| 07:31a  07:37p  12:05 | 08:40p  06:28a |      Rise 10:50p   58%|
|Tue 24| 07:33a  07:35p  12:02 | 08:38p  06:29a |L Qtr Rise 11:47p   48%|
|Wed 25| 07:34a  07:33p  11:59 | 08:36p  06:30a |      Rise 12:53a   37%|
|Thu 26| 07:35a  07:31p  11:56 | 08:34p  06:32a |      Rise 02:02a   28%|
|Fri 27| 07:36a  07:29p  11:53 | 08:32p  06:33a |      Rise 03:11a   20%|
|Sat 28| 07:37a  07:27p  11:50 | 08:30p  06:34a |      Rise 04:18a   12%|
+------+-----------------------+----------------+-----------------------+
|Sun 29| 07:39a  07:25p  11:46 | 08:28p  06:35a |      Rise 05:24a    7%|
|Mon 30| 07:40a  07:24p  11:43 | 08:27p  06:37a |      Rise 06:27a    3%|
+-----------------------------------------------------------------------+
* 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: 08/30/2024 – Star party tomorrow night

August 30, 2024 Comments off

This is Ephemeris for Friday, August 30th. Today the Sun will be up for 13 hours and 18 minutes, setting at 8:22, and it will rise tomorrow at 7:04. The Moon, 3 days before new, will rise at 4:11 tomorrow morning.

Weather permitting, a Star Party will be held tomorrow night at the Sleeping Bear Dunes National Lakeshore at the Dune Climb. The viewing will start at 9 pm. These events will be hosted by the park rangers and the Grand Traverse Astronomical Society, who will bring their telescopes to view the heavens, including the planet Saturn and the wonders of the summer Milky Way. The telescopes will be setup in the parking area closest to the dune. While twilight fades Saturn will be about the only object to view in the east-southeast. As it gets darker more and more wonders of the Milky Way will be seen. They include star clusters and nebulae, clouds of gas and dust that lie in abundance in the Milky Way.

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

Setting up for a star party the Dune Climb
Setting up for a star party the Dune Climb. A few of the telescopes are visible including the GTAS 25 inch “Emmettron” telescope at the far right background. Credit: Eileen Carlisle.
Categories: Ephemeris Program, GTAS Outreach Event, Observing, Star Party Tags: , ,

Ephemeris: 08/29/2024 – Centaur or Teapot, you decide!

August 29, 2024 Comments off

This is Bob Moler with Ephemeris for Thursday, August 29th. Today the Sun will be up for 13 hours and 21 minutes, setting at 8:23, and it will rise tomorrow at 7:03. The Moon, 3 days past last quarter, will rise at 3:02 tomorrow morning.

Low in the south at 10 PM shines the heart of summer Milky Way. The constellation that’s seen there is Sagittarius which is supposed to be a centaur with a bow and arrow. We modern folk haven’t seen a centaur outside a Harry Potter movie, so we see its stars looking like a teapot, a short and stout little teapot like in the children’s song. It is tipped to the West with the Milky Way like steam rising from its spout, which is about to pour its tea on the southwestern horizon later tonight. Sagittarius is just begging to be explored with binoculars or a very low power telescope to see its myriad of stars, star clusters and nebulae. As fabulous as all this appears, we cannot see into the heart of the Milky Way for all the clouds of dust and gas in the way.

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

A series of frames of Sagittarius showing how authors have the seen the stick figures of the stars in Sagittarius and Scorpius
Here are a series of frames of Sagittarius showing how authors have the seen the stick figures of the stars in Sagittarius and Scorpius. The 1st frame shows the sky as it would be seen with the naked eye. The 2nd frame shows the lines from Stellarium that it calls the Western sky lore. The 3rd frame is from a book by H. A. Rey titled The Stars a New Way to See Them. It came out in 1952 about the time I became interested in astronomy although I never bought the book. It’s his attempt to match the lines between the stars with the constellation figure. The 4th frame shows the constellation art that’s provided with Stellarium showing a centaur aiming for Scorpius the scorpion. The 5th frame shows the Teapot asterism as I have described in the text. This is easiest to see especially that Sagittarius is very low in our sky and the faint stars that would delineate a Centaur are lost due to the great amount of atmosphere that we have to look through to see them. Click or tap on the image to enlarge it. Created using Stellarium and GIMP.

My first guide to the constellations was Stars by Zim and Baker, a Golden Guide. I checked, it has been revised and is still available. H. A. Rey’s book is also still available.

Categories: Asterism, Constellations, Ephemeris Program Tags: , ,

Ephemeris: 08/28/2024 – Where are the naked-eye planets this week?

August 28, 2024 Comments off

This is Ephemeris for Wednesday, August 28th. Today the Sun will be up for 13 hours and 24 minutes, setting at 8:25, and it will rise tomorrow at 7:02. The Moon, 2 days past last quarter, will rise at 1:55 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus might be glimpsed low in the west around 8:45 PM. It will set at 9:19. It is best seen over a very low or lake horizon. Saturn will rise at 8:52 pm, and by 10 pm will be low in the east-southeast, pretty much by itself. Saturn may look disappointing in telescopes this year since its rings are nearly edge on and appear almost as a line through the planet. Jupiter and Mars will be up in the east in the morning, and by 6 am tomorrow, Jupiter will be the brightest starlike object in the sky among the winter stars. Mars will be just below it to the left. And the waning crescent Moon below left of Mars. Jupiter will rise at 12:42 AM, with Mars rising at 1:09 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

This is what Venus might look like 20 minutes after sunset
This is what Venus might look like 20 minutes after sunset or around 8:45 PM tonight, August 28, 2024 in northwestern lower Michigan, looking over a Lake Michigan horizon. Created using Stellarium.
Saturn as it might be seen low in the east southeast at 9:30 PM
Saturn as it might be seen low in the east southeast at 9:30 PM tonight, August 28, 2024. Created using Stellarium.
Mars and Jupiter among the bright winter stars
Mars and Jupiter among the bright winter stars, and above the constellation of Orion with its bright stars Betelgeuse and Rigel. Also visible is the waning crescent Moon and the rising Mercury at 6:00 AM tomorrow morning, August 29th 2024. Created using Stellarium.
The Moon as it might appear through a small telescope
The Moon as it might appear through a small telescope tomorrow morning, August 29th 2024. Selected features are labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
Telescopic Venus, Saturn and Jupiter
Telescopic Venus, Saturn and Jupiter (north up) as they would be seen in a small telescope with the same magnification. Venus and Saturn are from the evening of the 28th, Jupiter is for 6 am on the 29th. Apparent diameters: Venus 10.9″, 91.7% illuminated; Saturn 19.2″, its rings 44.6″, 3.4 degrees from edge on (opening up a bit); Jupiter 38.2″; Mars, too small to be represented here, is 6.2″. Mercury, also too small 8.9 and 18.5% illuminated. Notes: Jupiter’s moon Io will be visible until 5:42 AM. It will not be visible as shown at 6 AM. The ” means seconds of arc, or 1/3600th of a degree. Click or tap on the image to enlarge it. Created using Cartes du Ciel (Sky Charts).
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 August 28, 2024. The night ends on the left with sunrise on August 29th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
This is 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, August 28 and 29 2024. Some of the columns are self-explanatory, others 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 by my Ephemeris Helper app.
Categories: Ephemeris Program, Naked-eye planets, Observing, Planets Tags: , , , , ,

Ephemeris: 08/27/2024 – Space news

August 27, 2024 Comments off

Sorry, about posting this late. I was working on our astronomical society article and newsletter. The article will be posted as an Ephemeris Extra in a couple of weeks. For a preview see my August 22nd post.

This is Ephemeris for Tuesday, August 27th. Today the Sun will be up for 13 hours and 27 minutes, setting at 8:27, and it will rise tomorrow at 7:01. The Moon, 1 day past last quarter, will rise at 12:55 tomorrow morning.

Let’s take a look at some space news. Today is the first day of the launch window for the SpaceX commercial mission Polaris Dawn where 4 private astronauts will ride a SpaceX Dragon capsule to the highest point astronauts have been since the Apollo days, some 1400 kilometers or 870 miles above the Earth. They will also perform the first commercial EVA or space walk. Two of the astronauts will take turns poking their body out the hatch capsule for a short period of time. They will not be free floating, but they will be connected to the capsule by foot or hand restraints.

In other news NASA has decided to bring Suni Williams and Butch Wilmore, the Boeing Starliner test astronauts, back to Earth on a Dragon capsule in February due to safety concerns.

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 Boeing Starliner Calypso
The Boeing Starliner Calypso seen docked to the International Space Station. Credit NASA. For more on the decision to bring back the Starliner without its crew see: https://news.yahoo.com/news/boeings-starliner-comes-back-empty-153705167.html
Image of the proposed Polaris Dawn EVA. This contrasts with the previous image put out of the astronaut floating free on a tether outside the space capsule. Actually no useful work can be done free floating in space. The astronaut always has to be attached to something to provide leverage for a task, otherwise they would just sort of spin out of control. As a precaution the nose cover of the capsule will be facing into their direction of travel to provide some protection for the astronaut from micrometeoroid debris that they might encounter. Credit SapceX/Polaris Dawn.
Categories: Ephemeris Program, Space Flight Tags: , , , , ,

Ephemeris: 08/26/2024 – Scanning the Milky Way with binoculars

August 26, 2024 Comments off

This is Ephemeris for Monday, August 26th. Today the Sun will be up for 13 hours and 30 minutes, setting at 8:29, and it will rise tomorrow at 6:59. The Moon, at last quarter today, will rise at 12:06 tomorrow morning.

Now that the Moon has left the evening sky the Milky Way dominates the sky from northeast to south-southwest. The best way to appreciate the Milky Way is with binoculars and just scan through the Milky Way as Galileo did with this primitive telescope. What he found was that the glow of the Milky Way resolved itself into individual stars, thousands upon thousands of stars, each too faint to be perceived with the naked eye. At many places in the Milky Way there are fuzzy spots. These could be nebulae, clouds of gas lit up by the stars within them, or clusters of stars not quite resolvable by binoculars, that can be studied in more detail with a larger telescope. Wandering through the Milky Way with binoculars can give hours of enjoyment.

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 Milky Way from Cygnus to Scutum
The Milky Way from Cygnus to Scutum. I this image, actually a stack of 5 images, on August 12, 2018. I was hoping to record Perseid meteors. It was a poor showing, as none appeared in these images. We were hampered that year by smoke from the western US wildfires which really affected the lower part of this image, which was still pretty high up in the sky. Featured here is the Great Rift, a series of dust clouds that split the Milky Way into two sections. Credit Bob Moler (me).

Categories: Ephemeris Program Tags: ,

Ephemeris: 08/23/2024 – The dimmest star of the Summer Triangle is really the brightest

August 23, 2024 Comments off

This is Ephemeris for Friday, August 23rd. Today the Sun will be up for 13 hours and 39 minutes, setting at 8:34, and it will rise tomorrow at 6:56. The Moon, 3 days before last quarter, will rise at 10:29 this evening.

This evening when it gets dark enough the bright star Deneb in Cygnus the swan will be very high in the east. Deneb is the dimmest star of the Summer Triangle. Of the other stars of the triangle, Vega is nearly overhead, while Altair is lower in the south-southeast. Deneb’s apparent magnitude, or brightness as seen from Earth, makes it the dimmest of the three bright stars. Its vast distance of possibly 2,600 light years is over 100 times the distance of Vega. If brought as close as Vega, Deneb would be as at least as bright as the quarter moon. It is possibly as bright as 200 thousand Suns; and a huge star, possibly as large in diameter as the orbit of the Earth. For all this it is only 19 or so times the mass of the Sun.

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 constellations Lyra, Cygnus and Aquila
Deneb with the other stars and constellations in the Summer Triangle. Created using Stellarium.
Deneb & North American Nebula
One of my old photographs of Deneb and the North American Nebula which it illuminates, digitized from a slide.
Categories: Ephemeris Program, Stars Tags: