Ephemeris: 09/11/2023 – Scutum, an almost invisible constellation in the Milky Way
This is Ephemeris for Monday, September 11th. Today the Sun will be up for 12 hours and 44 minutes, setting at 8:01, and it will rise tomorrow at 7:17. The Moon, 3 days before new, will rise at 4:32 tomorrow morning.
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 Kalenberg 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 the Egyptian Queen Berenice’s hair. However, 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 for star clusters and nebulae, clouds of dust and gas.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
Ephemeris: 09/08/2023 – Comet Nishimura is getting brighter as it approaches the Sun, but also encountering brighter twilight
This is Ephemeris for Friday, September 8th. Today the Sun will be up for 12 hours and 53 minutes, setting at 8:06, and it will rise tomorrow at 7:14. The Moon, 2 days past last quarter, will rise at 1:20 tomorrow morning.
Our comet Nishimura is the third comet discovered by Japanese amateur astronomer Hideo Nishimura. Somehow the near earth asteroid detection programs missed it. I can understand why the Pan-STARRS and ATLAS search programs missed it, since they’re located on the Island of Maui, where those devastating wildfires are located. But they aren’t the only search programs. This weekend is the last chance to spot the comet. Nishimura will be rising before 5:30 am. The comet will be increasing its brightness to 4th magnitude this weekend. However, it will still be difficult to pick out without a pair of binoculars. The tail, if it has any, will be pointed just about straight up. After the 17th, its perihelion, it will be heading southward, and back out to the Oort Cloud, from where it came.
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
Comet Nishimura Saturday, September 9th, 6 am
Comet Nishimura Sunday, September 10th, 6 am
Comet Nishimura Monday, September 11th, 6:15 am
After Monday, September 11th I feel that the comet will be too close to the Sun, or in too bright a twilight to spot for our latitude. Observers farther south should have better luck after perihelion on the 17th.
Ephemeris: 09/07/2023 – Comet Nishimura is getting brighter as it approaches the Sun
This is Ephemeris for Thursday, September 7th. Today the Sun will be up for 12 hours and 56 minutes, setting at 8:08, and it will rise tomorrow at 7:13. The Moon, 1 day past last quarter, will rise at 12:26 tomorrow morning.
Comet Nishimura is brightening as it approaches the Sun. It will reach 22% of the Earth’s distance from the Sun at perihelion, its closest to the Sun on the 17th, but will be heading south of the Sun, and not be visible to us. Currently, it is in the morning sky, in the east-northeast. At 6 to 6:30 am it will appear in the east-northeast to the left of Venus. It will be probably 4.4 magnitude, which still isn’t easily spotted in a dark sky, much less in the morning twilight glow. If it does have a tail, it will be pointed vertically up from the head of the comet. A pair of binoculars will be needed to spot the comet. Nishimura appears to be a visitor from the Oort cloud of comets, a cloud that stretches about a quarter the way to the next star to the Sun.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
Ephemeris: 09/06/2023 – Let’s find out where the naked-eye planets and comet Nishimura have wandered off to
This is Ephemeris for Wednesday, September 6th. Today the Sun will be up for 12 hours and 59 minutes, setting at 8:10, and it will rise tomorrow at 7:12. The Moon, at last quarter today, will rise at 11:40 this evening.
Let’s find out where the naked-eye planets have wandered off to. Three of those five planets are now visible but Mars and Mercury are too close to the Sun to be seen. Saturn is the sole evening planet visible. Jupiter and Venus are officially the only visible morning planets. Saturn can be spotted in the southeast in the evening. And it will still be visible throughout the morning hours morning until twilight starts. Saturn is in retrograde or westward motion against the stars of Aquarius. Jupiter will rise at 10:54pm. It is slowing its eastward motion and will become stationary tomorrow. Venus is our brilliant morning star. It will rise at 4:43 tomorrow morning. Comet Nishimura is left and a bit below Venus in the east-northeast.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
Ephemeris: 09/05/2023 – Where is Comet Nishimura tomorrow morning the 6th
This is Bob Moler with Ephemeris for Tuesday, September 5th. Today the Sun will be up for 13 hours and 2 minutes, setting at 8:12, and it will rise tomorrow at 7:10. The Moon, 1 day before last quarter, will rise at 11:03 this evening.
Comet Nishimura is supposedly a very dim naked-eye comet now, best found and seen in binoculars, though it will get brighter in the next few days. On Ephemeris, when I talk about things that one can observe, it must be bright enough to be spotted with the naked eye, even though it may be best appreciated with binoculars or telescope. This comet is a little dubious in that regard. Comets, to my eyes at least, appear dimmer than what their magnitudes suggest. More specific information is on my blog at bobmoler.wordpress.com, an Ephemeris Extra post for August 31st. Tomorrow morning the comet is to the left of Venus in the east northeast. Comet Nishimura will be visible for our location through next Monday.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
Ephemeris: 09/04/2023 – One more look at Saturn’s Rings
This is Bob Moler with Ephemeris for Labor Day, Monday, September 4th. Today the Sun will be up for 13 hours and 5 minutes, setting at 8:14, and it will rise tomorrow at 7:09. The Moon, 2 days before last quarter, will rise at 10:32 this evening.
We are going to take one more look at Saturn’s rings, and these are the rings which are not visible from the Earth, but only from spacecraft in the vicinity of Saturn. We have the A, B and C rings which are visible from here Then there’s a D ring inside the C ring. There’s the F ring, a very thin ring which is controlled by a tiny moon called Prometheus, just outside the A ring. Farther out there’s an E ring which is a very diffuse ring, in the orbit of the moon Enceladus, which is an active satellite. It has geysers at the at its South Pole which vent water ice and organic compounds, which form the E ring. Saturn has many more rings and ring arcs in orbit around it, too numerous to mention here.
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
Off-topic
Ephemeris: 09/01/2023 – GTAS meeting tonight – Dr. Jerry Dobek goes over to the dark side
This is Ephemeris for Friday, September 1st. Today the Sun will be up for 13 hours and 14 minutes, setting at 8:19, and it will rise tomorrow at 7:06. The Moon, 2 days past full, will rise at 9:24 this evening.
Tonight at 8 p.m. at the meeting of the Grand Traverse Astronomical Society at Northwestern Michigan College’s Rogers Observatory, and on Zoom. Observatory Director Dr. Jerry Dobek will be giving a talk on what he calls dark material. This is from a new book he collaborated on: The Barnard Objects – Then and Now, a look at dark nebulae, comparing E. E. Barnard’s Black and White photographic plates to modern color digital photography. Dark nebulae are clouds of gas and dust seen in the summer Milky Way. After the meeting, at 9 p.m. the society will host a star party to view a rather bright night sky including Saturn. The observatory is located south of Traverse City on Birmley Road between Garfield and Keystone roads. Zoom instructions will be at gtastro (dot) org.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT –4 hours). They may be different for your location.
Addendum
Ephemeris Extra: 08/31/2023 – Comet C/2023 P1 (Nishimura) may be visible to the naked eye in September
Comet Nishimura is shown at 6:30 AM in the east northeast for the mornings of September 1st through 11th. Venus stays pretty much at the same altitude of 14 degrees during this period. The Sun is shown here below the horizon. The comet and the Sun are labeled every other day with the month and day and estimated magnitude. Created using Cartes du Ciel (Sky Charts) by the author.
On August 12th this year Hideo Nishimura of Kakegawa, Japan discovered a comet that now bears his name. The comet has a chance of becoming a naked eye object this month, but for only a few days. It is a rapidly moving comet, and it is heading southward. We will only get a short period of time when it is possibly visible to the naked eye.
I’m sorry about all the weasel words about the brightness of the comet, but comets are notorious for being unpredictable with their brightness. They may brighten suddenly, they may dim suddenly, they may fall apart. We never know what happens to a comet until it happens.
Early brightness estimates were all over the place from 9th to 14th magnitude a range of 5 magnitudes or a brightness range of 100 from bright to dim. The comet was discovered only 12 days ago, as I write this, so there’s not very many brightness estimates to base future magnitudes on, even if the comet is well-behaved.
I’ve printed a chart, below, of the comet’s position in relation to the stars of Cancer and Leo for the period September 1 through 13th. The comet should be at least a binocular object during this period. I’ve also included a table of comet positions in altitude and azimuth for the start of astronomical and nautical twilight. The times of morning nautical twilight are listed on the Star Chart Page. Astronomical twilight starts about 36 minutes before nautical twilight this time of year.
Comet Nishimura plotted against the stars of Cancer and Leo, along with the Sun and Venus. The comet, Venus and the Sun are labeled every other day with the month and day and estimated magnitude. Created using Cartes du Ciel (Sky Charts) by the author.
A pair of binoculars are the best way to view a comet that is just barely visible to the naked eye, or is competing with twilight. In both charts, the tail of the comet shows the direction that the tail would flow from and not its length.
A table of positions of the comet at the beginning of astronomical and nautical twilight. Created using Cartes du Ciel.
At last report (August 26), it was half a magnitude dimmer than the predictions I have.
Ephemeris: 08/31/2023 – Looking ahead to September’s skies
This is Ephemeris for Thursday, August 31st. Today the Sun will be up for 13 hours and 17 minutes, setting at 8:21, and it will rise tomorrow at 7:04. The Moon, 1 day past full, will rise at 9:02 this evening.
Let’s look at the skies of September which starts tomorrow. The Sun will be moving at its greatest speed in its retreat to the south. Daylight hours in the Interlochen/Traverse City area will drop from 13 hours and 14 minutes tomorrow to 11 hours 46 minutes on the 30th. The altitude of the Sun above the southern horizon at local noon will be 53 degrees tomorrow, and will descend to 42 degrees on the 30th. The Straits* area will see the Sun a degree lower. The season of summer is getting short, so enjoy it while you can. Summer ends and fall begins at 12:50 a.m. on the 23rd, the autumnal equinox. Venus is our brilliant Morning Star now, And on the 29th we’ll have the Harvest Moon, the nearest full moon to the autumnal equinox. There is a comet approaching the Sun in the first half of September, It will be described in an Ephemeris Extra later today.
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.
*For those not familiar with our area the Straits refer to the Straits of Mackinac (pronounced Mackinaw) that separate the Upper and Lower Peninsulas of Michigan.
Addendum
September Evening Star Chart
Star Chart for September 2023. 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
Star Chart for September 2023 (6 am EDT, September 15, 2022). 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. |
| 2023-09-01 | 5h26m | 6h04m | 21h29m | 22h08m | – | – | 0.93 |
| 2023-09-02 | 5h27m | 6h05m | 21h27m | 22h05m | – | – | 0.86 |
| 2023-09-03 | 5h29m | 6h07m | 21h25m | 22h03m | 22h03m | 22h07m | 0.78 |
| 2023-09-04 | 5h30m | 6h08m | 21h23m | 22h01m | 22h01m | 22h33m | 0.68 |
| 2023-09-05 | 5h32m | 6h09m | 21h21m | 21h59m | 21h59m | 23h03m | 0.57 |
| 2023-09-06 | 5h34m | 6h11m | 21h19m | 21h56m | 21h56m | 23h41m | 0.47 |
| 2023-09-07 | 5h35m | 6h12m | 21h17m | 21h54m | 21h54m | – | 0.37 |
| 2023-09-08 | 5h37m | 6h13m | 21h15m | 21h52m | 21h52m | 0h27m | 0.28 |
| 2023-09-09 | 5h38m | 6h15m | 21h13m | 21h50m | 21h50m | 1h21m | 0.20 |
| 2023-09-10 | 5h40m | 6h16m | 21h11m | 21h48m | 21h48m | 2h22m | 0.13 |
| 2023-09-11 | 5h41m | 6h17m | 21h09m | 21h46m | 21h46m | 3h27m | 0.07 |
| 2023-09-12 | 5h42m | 6h19m | 21h07m | 21h43m | 21h43m | 4h32m | 0.03 |
| 2023-09-13 | 5h44m | 6h20m | 21h05m | 21h41m | 21h41m | 5h38m | 0.01 |
| 2023-09-14 | 5h45m | 6h21m | 21h03m | 21h39m | 21h39m | 5h45m | 0.00 |
| 2023-09-15 | 5h47m | 6h23m | 21h01m | 21h37m | 21h37m | 5h47m | 0.01 |
| 2023-09-16 | 5h48m | 6h24m | 20h59m | 21h35m | 21h35m | 5h48m | 0.04 |
| 2023-09-17 | 5h50m | 6h25m | 20h57m | 21h33m | 21h33m | 5h50m | 0.09 |
| 2023-09-18 | 5h51m | 6h27m | 20h55m | 21h31m | 21h31m | 5h51m | 0.16 |
| 2023-09-19 | 5h52m | 6h28m | 20h53m | 21h28m | 21h39m | 5h52m | 0.24 |
| 2023-09-20 | 5h54m | 6h29m | 20h51m | 21h26m | 22h10m | 5h54m | 0.33 |
| 2023-09-21 | 5h55m | 6h30m | 20h49m | 21h24m | 22h52m | 5h55m | 0.44 |
| 2023-09-22 | 5h57m | 6h32m | 20h47m | 21h22m | 23h46m | 5h57m | 0.55 |
| 2023-09-23 | 5h58m | 6h33m | 20h45m | 21h20m | – | 5h58m | 0.66 |
| 2023-09-24 | 5h59m | 6h34m | 20h43m | 21h18m | 0h53m | 5h59m | 0.76 |
| 2023-09-25 | 6h01m | 6h35m | 20h41m | 21h16m | 2h11m | 6h01m | 0.85 |
| 2023-09-26 | 6h02m | 6h37m | 20h39m | 21h14m | 3h35m | 6h02m | 0.93 |
| 2023-09-27 | 6h03m | 6h38m | 20h37m | 21h12m | 4h59m | 6h03m | 0.98 |
| 2023-09-28 | 6h05m | 6h39m | 20h36m | 21h10m | – | – | 1.00 |
| 2023-09-29 | 6h06m | 6h40m | 20h34m | 21h08m | – | – | 0.99 |
| 2023-09-30 | 6h07m | 6h42m | 20h32m | 21h06m | – | – | 0.96 |
Twilight calendar was generated using Cartes du Ciel (Sky Charts).
See my blog post: Twilight Zone for the definitions of the different periods of twilight here: https://bobmoler.wordpress.com/2018/09/27/.
NASA Calendar of Planetary Events
Date Time Event
Sep 1 Fr Venus: 27.4° W
3 Su 3:44 am Moon Ascending Node
4 Mo 3:44 pm Moon-Jupiter: 3.4° S
5 Tu 3:25 pm Moon-Pleiades: 1.3° N
6 We 7:03 am Mercury Inferior Conj.
6 We 6:21 pm Last Quarter
8 Fr 9:18 am Moon North Dec.: 28.2° N
9 Sa 11:32 pm Moon-Pollux: 1.7° N
12 Tu 11:42 am Moon Apogee: 406,300 km
14 Th 9:40 pm New Moon
17 Su 11:12 am Moon-Spica: 2.6° S
17 Su 3:18 pm Moon Descending Node
19 Tu Venus greatest brilliancy
19 Tu 5:54 am Neptune Opposition
21 Th 3:50 am Moon-Antares: 0.9° S
22 Fr 8:59 am Mercury Elongation: 17.9° W
Favorable greatest elongation for
the Northern Hemisphere.
22 Fr 3:32 pm First Quarter
22 Fr 11:42 pm Moon South Dec.: 28.3° S
23 Sa 2:50 am Autumnal Equinox
26 Tu 9:25 pm Moon-Saturn: 2.6° N
27 We 9:05 pm Moon Perigee: 359,900 km
29 Fr 5:57 am Full Harvest Moon
30 Sa 12:49 pm Moon Ascending Node
Oct 1 Su Venus: 44.2° W
All event times are given for UTC-4 hr: Eastern Daylight Saving Time.
Sky Events Calendar by Fred Espenak and Sumit Dutta (NASA’s GSFC),
http://eclipse.gsfc.nasa.gov/SKYCAL/SKYCAL.html.
If you go to the above site, you can print out a list like the above for the entire year or calendar pages for your time zone.
Sun and Moon Rising and Setting Events
Ephemeris of Sky Events for Interlochen/TC September 2023 Local time zone: EDT +-----------------------------------------------------------------------+ | DATE | SUN SUN DAYLIGHT| TWILIGHT* |MOON RISE OR ILLUM | | | RISE SET HOURS | END START |PHASE SET** TIME FRACTN| +=======================================================================+ |Fri 1| 07:04a 08:19p 13:14 | 09:26p 05:58a | Rise 09:24p 94%| |Sat 2| 07:06a 08:18p 13:11 | 09:24p 05:59a | Rise 09:45p 88%| +------+-----------------------+----------------+-----------------------+ |Sun 3| 07:07a 08:16p 13:08 | 09:21p 06:01a | Rise 10:07p 79%| |Mon 4| 07:08a 08:14p 13:05 | 09:19p 06:02a | Rise 10:32p 70%| |Tue 5| 07:09a 08:12p 13:02 | 09:17p 06:03a | Rise 11:03p 60%| |Wed 6| 07:10a 08:10p 12:59 | 09:15p 06:05a |L Qtr Rise 11:40p 49%| |Thu 7| 07:12a 08:08p 12:56 | 09:13p 06:06a | Rise 12:26a 39%| |Fri 8| 07:13a 08:06p 12:53 | 09:11p 06:08a | Rise 01:20a 30%| |Sat 9| 07:14a 08:05p 12:50 | 09:09p 06:09a | Rise 02:21a 22%| +------+-----------------------+----------------+-----------------------+ |Sun 10| 07:15a 08:03p 12:47 | 09:07p 06:10a | Rise 03:26a 14%| |Mon 11| 07:16a 08:01p 12:44 | 09:05p 06:12a | Rise 04:32a 8%| |Tue 12| 07:17a 07:59p 12:41 | 09:03p 06:13a | Rise 05:37a 4%| |Wed 13| 07:19a 07:57p 12:38 | 09:01p 06:14a | Rise 06:41a 1%| |Thu 14| 07:20a 07:55p 12:35 | 08:59p 06:15a |New Set 08:04p 0%| |Fri 15| 07:21a 07:53p 12:32 | 08:57p 06:17a | Set 08:20p 1%| |Sat 16| 07:22a 07:51p 12:29 | 08:55p 06:18a | Set 08:36p 3%| +------+-----------------------+----------------+-----------------------+ |Sun 17| 07:23a 07:50p 12:26 | 08:53p 06:19a | Set 08:54p 8%| |Mon 18| 07:24a 07:48p 12:23 | 08:51p 06:21a | Set 09:14p 14%| |Tue 19| 07:26a 07:46p 12:20 | 08:49p 06:22a | Set 09:39p 22%| |Wed 20| 07:27a 07:44p 12:17 | 08:47p 06:23a | Set 10:10p 31%| |Thu 21| 07:28a 07:42p 12:13 | 08:45p 06:24a | Set 10:51p 41%| |Fri 22| 07:29a 07:40p 12:10 | 08:43p 06:26a |F Qtr Set 11:45p 52%| |Sat 23| 07:30a 07:38p 12:07 | 08:41p 06:27a | Set 12:52a 63%| +------+-----------------------+----------------+-----------------------+ |Sun 24| 07:32a 07:36p 12:04 | 08:39p 06:28a | Set 02:11a 74%| |Mon 25| 07:33a 07:34p 12:01 | 08:38p 06:30a | Set 03:34a 84%| |Tue 26| 07:34a 07:33p 11:58 | 08:36p 06:31a | Set 04:59a 91%| |Wed 27| 07:35a 07:31p 11:55 | 08:34p 06:32a | Set 06:22a 97%| |Thu 28| 07:36a 07:29p 11:52 | 08:32p 06:33a | Set 07:43a 100%| |Fri 29| 07:38a 07:27p 11:49 | 08:30p 06:35a |Full Rise 07:45p 99%| |Sat 30| 07:39a 07:25p 11:46 | 08:28p 06:36a | Rise 08:07p 96%| +-----------------------------------------------------------------------+ * Nautical Twilight ** Moonrise or moonset, whichever occurs between sunrise and sunset
Generated using my LookingUp for DOS program.
Ephemeris: 08/30/2023 – Let’s find out where the naked-eye planets are
This is Ephemeris for Wednesday, August 30th. Today the Sun will be up for 13 hours and 20 minutes, setting at 8:23, and it will rise tomorrow at 7:03. The Moon, is the full Blue Moon today, and it will rise at 8:39 this evening. No, it’s not really blue in color. The Blue Moon is the second full moon in a particular month.
Let’s find out where the naked-eye planets are. Three of those five planets are now visible. Mars and Mercury are too close to the Sun to be seen. Saturn is the sole evening planet visible. Jupiter and Venus are officially the only visible morning planets. Saturn can be spotted in the southeast in the evening. And it will still be visible throughout the morning hours until just before sunrise. Tonight Saturn will appear above and right of the full moon, though it might be difficult to spot in the Moon’s glare. Saturn is in retrograde or westward motion now, against the stars of Aquarius. Jupiter will rise at 10:54pm. It is slowing its eastward motion and will become stationary on September 7th. Venus is making an appearance in the morning sky now as our brilliant morning star. It will rise at 5:13 tomorrow morning.
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 naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on August 30, 2023. The night ends on the left with sunrise on the 31st. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
