07/10/2020 – Ephemeris – The constellation Cygnus the swan

This is Bob Moler with Ephemeris for Friday, July 10th. Today the Sun will be up for 15 hours and 20 minutes, setting at 9:28, and it will rise tomorrow at 6:08. The Moon, 2 days before last quarter, will rise at 12:52 tomorrow morning.

Fairly high in the east at 11 p.m. Is the constellation of Cygnus the swan, flying south through the Milky Way. It is also called the Northern Cross. At the left, the tail of the swan or the head of the cross is the bright star Deneb, one of the stars of the Summer Triangle. The next star right is Sadr the intersection of the body and the wings of the swan seen in flight, or the intersection of the two pieces of the cross. There are two or three stars farther to the right that delineate the swan’s long neck or upright of the cross, that ends with the star Alberio in the beak of the swan or foot of the cross. The crosspiece of the cross extends to the stars on either side of the intersection star Sadr, while the swan’s wings extend to a couple more stars each.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Animated Cygnus finder chart. Included also are, beside Deneb, the other stars of the Summer Triangle: Vega and Altair and their constellations Lyra the harp and Aquila. See if you can find them. Click on the image to enlarge it. Created using Stellarium.

07/09/2020 – Ephemeris – The constellation of Lyra the harp

Jul 9. This is Bob Moler with Ephemeris for Thursday, July 9th. Today the Sun will be up for 15 hours and 22 minutes, setting at 9:29, and it will rise tomorrow at 6:07. The Moon, 3 days before last quarter, will rise at 12:30 tomorrow morning.

High in the east at 11 p.m. can be found a bright star just above a small, narrow, but very distinctive parallelogram of stars. They are the stars of the constellation Lyra the harp. The bright star is Vega the 5th brightest night-time star. To the Romans the star Vega represented a falling eagle or vulture. Apparently they never made the distinction between the two. It is a pure white star and serves as a calibration star for color and brightness. The harp, according to Greek mythology, was invented by the god Hermes. The form of the harp in the sky, is as he had invented it: by stretching strings across a tortoise-shell. Hermes gave it to his half-brother Apollo, who in turn gave it to the legendary musician Orpheus.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Lyra as a tortoise shell harp. Created using Stellarium and free clip art.

07/08/2020 – Ephemeris – Let’s look at the naked-eye planets and a comet for this week

This is Bob Moler with Ephemeris for Wednesday, July 8th. Today the Sun will be up for 15 hours and 23 minutes, setting at 9:29, and it will rise tomorrow at 6:06. The Moon, 3 days past full, will rise at 12:05 tomorrow morning.

Let’s look at the naked-eye planets and a comet for this week. Jupiter now rises at 9:41 pm in the east-southeast. Saturn will rise 22 minutes later at 10:03 pm right behind Jupiter. Mars, is stretching its lead left of Saturn and will rise at 1 am in the east. Its now down to 71 and a half million miles (115.2 million km) away, as the Earth slowly overtakes it at the rate of about 3.9 million miles (6.2 million km) a week. Venus will rise at 3:47 am in the east-northeast as our Morning Star. Newly discovered Comet NEOWISE will rise at 3:16 am and be visible in the northeast before the twilit sky brightens too much. The comet gets its name from the NASA Satellite and mission to detect near Earth objects or NEOs in the infrared.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Saturn and Jupiter planets plus two southern constellations to the right of them at 11 pm tonight July 8, 2020. Just right of Jupiter is Sagittarius that looks more like a teapot than a centaur with a bow and arrow. Further right is Scorpius the scorpion. Click on the image to enlarge. Created using Stellarium.

Planets, the Moon and a comet visible at 5 am tomorrow morning July 9, 2020. Venus appears just above the star Aldebaran. Comet NEOWISE’ tail is visible, but not at this scale, and it is shown as being too bright. Click on the image to enlarge. Created using Stellarium.

The Moon as it might appear tomorrow morning at 5 a.m. July 9, 2020. Created using Stellarium.

The planets as seen in a telescope (north up) with the same magnification tonight and tomorrow July 8/9, 2020. Apparent diameters: Jupiter, 47.57″; Saturn, 18.43″, rings, 42.94″, Mars, 12.19″, and Venus 37.66″. Mars also displays an enlargement showing surface detail. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on July 8, 2020. The night ends on the left with sunrise on the 9th. The closeness of Jupiter and Saturn in the morning sky unfortunately overlays planets and labels. Click on the image to enlarge. Created using my LookingUp program.

07/07/2020 – Ephemeris – New Comet NEOWISE (C/2020 F3) is visible in the morning

This is Ephemeris for Tuesday, July 7th. Today the Sun will be up for 15 hours and 24 minutes, setting at 9:29, and it will rise tomorrow at 6:06. The Moon, 2 days past full, will rise at 11:37 this evening.

Comet C/2020 F3 (NEOWISE) is visible in the morning now, and quite bright. At 5 am in twilight it will be very low in the northeast tomorrow morning, below the bright star Capella. I’ve seen a photograph of it showing a tail. Over the next week it will be moving northward along the horizon at 5 am and fading as it goes. Then it will become visible in the evening sky next week. It is best seen in binoculars, though it can be spotted with the naked eye. One needs a low northeastern horizon. That’s the problem with comets: they’re brightest when close to the Sun, and can be seen best only when the Sun isn’t up. So that leaves morning or evening twilight, unless they are a huge comet like Hale-Bopp of 23 years ago that doesn’t get close to the Sun.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Comet NEOWISE starting at 5 am February 8, 2020. Every second date has month-day and predicted magnitude. The sky will be a bit higher each morning. Created using Cartes du Ciel (Sky Charts)

07/06/2020 – Ephemeris – The southernmost star of the Summer Triangle, Altair

This is Bob Moler with Ephemeris for Monday, July 6th. Today the Sun will be up for 15 hours and 25 minutes, setting at 9:30, and it will rise tomorrow at 6:05. The Moon, 1 day past full, will rise at 11:02 this evening.

The southernmost star of the Summer Triangle is Altair, high in the east-southeast. The other two stars of the triangle are Vega nearly overhead in the east, and Deneb high in the east-northeast. Altair is the closest of the three at a distance of 16.7 light years away. One light year is nearly 6 trillion miles. Altair is 10 times the brightness of the Sun. If seen at Altair’s distance, the Sun would only be as bright as one of the two stars that flank it. What is rather different about Altair is its rapid rotation. While it’s almost twice the sun’s diameter, it rotates once in about 9 hours, The CHARA Interferometer at Mt. Wilson has actually imaged its squashed disk in the infrared. Our Sun’s a slow poke, taking nearly a month to rotate once.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Summer Triangle. Created using Stellarium.

Lines added to show the rotation axis. Credit: Zina Deretsky, National Science Foundation.

 

 

07/03/2020 – Ephemeris – Grand Traverse Astronomical Society virtual meeting tonight

This is Bob Moler with Ephemeris for Friday, July 3rd. Today the Sun will be up for 15 hours and 28 minutes, setting at 9:31, and it will rise tomorrow at 6:03. The Moon, 2 days before full, will set at 5:18 tomorrow morning.

The Grand Traverse Astronomical Society will host a virtual meeting tonight at 8 pm. It is via the Zoom app for the smart phone, tablet or going to zoom.us with a browser on your computer. Instructions and a link can be found on the society’s website gtastro.org. With the Sun out so long now, I will be giving the presentation: The Sun and the Earth, about the relationship between the two bodies. I’ll talk about all the energy the Sun puts out and how the atmosphere protects us from some of it. We’ll look at the cause of the seasons, and why, in early July as summer is getting going the Earth is at its farthest from the Sun, and what effect that has on the our summers. And lots more.

07/02/2020 – Ephemeris – The star Deneb in Cygnus the swan

This is Ephemeris for Thursday, July 2nd. Today the Sun will be up for 15 hours and 29 minutes, setting at 9:31, and it will rise tomorrow at 6:02. The Moon, 3 days before full, will set at 4:29 tomorrow morning.

This evening when it gets dark enough the bright star Deneb in Cygnus the swan will be high in the east-northeast. Deneb is the dimmest star of the summer triangle. Of the other stars of the triangle, Vega is higher in the east, while Altair is lower in the 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 bright at least 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 event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Deneb with the other stars and constellations in the Summer Triangle. Created using Stellarium.

One of my old photographs of Deneb and the North American Nebula digitized from a slide.

07/01/2020 – Ephemeris – Let’s look at the naked-eye planets for this week

This is Ephemeris for Wednesday, July 1st. Today the Sun will be up for 15 hours and 30 minutes, setting at 9:31, and it will rise tomorrow at 6:01. The Moon, 3 days past first quarter, will set at 3:49 tomorrow morning.

Let’s look at the naked-eye planets for this week. Jupiter now rises in the evening, tonight it’s at 10:08 pm in the east-southeast. Saturn will rise 19 minutes later at 10:27 pm right behind Jupiter. Mars, is stretching its lead left of Saturn and will rise at 1:18 am in the east. Its now down to 75.4 million miles (121.5 million km) away, as the Earth slowly overtakes it at the rate of about 4 million miles (6.4 million km) a week. Jupiter and Saturn will be hanging out between Sagittarius and Capricornus this year while Mars is slowing its rapid eastward motion now two constellations over in Pisces. Finally, Venus will rise at 4:05 am in the east-northeast in the twilight as our Morning Star.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Almost evening planets Jupiter and Saturn, and the Moon at 11 pm on July 1st, 2020. Both Jupiter and Saturn are still officially morning planets since they rise after sunset. Click on the image to enlarge. Created using Stellarium.

The gibbous Moon as it might appear this evening, July 1st, 2020, in a pair of binoculars or small telescope. Created using Stellarium.

The morning planets, including Jupiter and Saturn which are also visible in the late evening. Click on the image to enlarge. Created using Stellarium.

The planets as seen in a telescope (north up) with the same magnification tomorrow morning July 2, 2020. Apparent diameters: Jupiter, 47.34″; Saturn, 18.37″, rings, 42.79″, Mars, 11.57″, and Venus 42.15″. Mars also displays an enlargement showing surface detail. The ” symbol means seconds of arc (1/3600th of a degree.) Created using Cartes du Ciel (Sky Charts).

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on July 1, 2020. The night ends on the left with sunrise on the 2nd. The closeness of Jupiter and Saturn in the morning sky unfortunately overlays planets and labels. Click on the image to enlarge. Created using my LookingUp program.

 

06/30/2020 – Ephemeris – Previewing the skies of July 2020

This is Ephemeris for Tuesday, June 30th. Today the Sun will be up for 15 hours and 31 minutes, setting at 9:32, and it will rise tomorrow at 6:01. The Moon, 2 days past first quarter, will set at 3:15 tomorrow morning.

Lets preview July’s skies. The Sun, having reached its northern solstice, is beginning to slide southward again, at first imperceptibly, then with greater speed. The daylight hours will decrease from 15 hours and 30 minutes tomorrow to 14 hours 40 minutes at month’s end. The daylight hours will be slightly shorter south of Interlochen, and slightly longer to the north. The altitude of the Sun at local noon, when it is due south will decrease from 68 degrees tomorrow to 63 degrees at month’s end. Despite the warmth, the Earth will reach its greatest distance from the Sun on Saturday the 4th. Both Jupiter and Saturn reach opposition from the Sun this month and officially become evening planets.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

July Evening Star Chart

Star Chart for July 2020 (11 p.m. EDT July 15, 2019). Created using my LookingUp program. Click on image to enlarge.

The planets and stars are plotted for the 15th at 11 p.m. EDT in the evening and 4:30 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.

Note the chart times are for the 15th. For each week before the 15th add ½ hour (28 minutes if you’re picky). For each week after the 15th subtract ½ hour. The planet positions are updated each Wednesday on this blog. For planet positions on dates other than the 15th.

July Morning Star Chart

Star Chart for July mornings 2020 (4:30 a.m. EDT July 15, 2019). Created using my LookingUp program. Click on image to enlarge.

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, and
• Extend like a spike to Spica.
• The Summer Triangle is in red.
• DAqR is the radiant of the South Delta Aquariid meteor shower (Peaks on the 27th)

Twilight Limits, Nautical and Astronomical

			EDT
	Morning twilight		Evening twilight		Dark night		Moon
Date	Astro.	Nautical	Nautical	Astro.	Start	End	Illum.
2020-07-01	3h38m	4h41m	23h00m	0h03m	3h15m	3h38m	0.88
2020-07-02	3h39m	4h42m	22h59m	0h02m	–	–	0.95
2020-07-03	3h40m	4h43m	22h59m	0h01m	–	–	0.95
2020-07-04	3h42m	4h43m	22h58m	0h00m	–	–	0.99
2020-07-05	3h43m	4h44m	22h58m	23h59m	–	–	1
2020-07-06	3h44m	4h45m	22h57m	23h58m	–	–	0.99
2020-07-07	3h46m	4h46m	22h56m	23h57m	–	–	0.95
2020-07-08	3h47m	4h47m	22h56m	23h56m	23h56m	–	0.89
2020-07-09	3h49m	4h48m	22h55m	23h54m	23h54m	0h05m	0.82
2020-07-10	3h50m	4h49m	22h54m	23h53m	23h53m	0h30m	0.74
2020-07-11	3h52m	4h51m	22h53m	23h52m	23h52m	0h52m	0.65
2020-07-12	3h54m	4h52m	22h52m	23h50m	23h50m	1h13m	0.55
2020-07-13	3h55m	4h53m	22h51m	23h49m	23h49m	1h33m	0.45
2020-07-14	3h57m	4h54m	22h50m	23h47m	23h47m	1h55m	0.36
2020-07-15	3h59m	4h55m	22h49m	23h46m	23h46m	2h19m	0.26
2020-07-16	4h01m	4h57m	22h48m	23h44m	23h44m	2h47m	0.18
2020-07-17	4h02m	4h58m	22h47m	23h43m	23h43m	3h20m	0.11
2020-07-18	4h04m	4h59m	22h46m	23h41m	23h41m	4h01m	0.05
2020-07-19	4h06m	5h01m	22h45m	23h39m	23h39m	4h06m	0.01
2020-07-20	4h08m	5h02m	22h44m	23h38m	23h38m	4h08m	0
2020-07-21	4h10m	5h03m	22h42m	23h36m	23h36m	4h10m	0.01
2020-07-22	4h12m	5h05m	22h41m	23h34m	23h34m	4h12m	0.06
2020-07-23	4h14m	5h06m	22h40m	23h32m	23h32m	4h14m	0.12
2020-07-24	4h16m	5h08m	22h38m	23h30m	23h58m	4h16m	0.21
2020-07-25	4h17m	5h09m	22h37m	23h28m	–	4h17m	0.32
2020-07-26	4h19m	5h10m	22h35m	23h26m	0h24m	4h19m	0.44
2020-07-27	4h21m	5h12m	22h34m	23h24m	0h50m	4h21m	0.56
2020-07-28	4h23m	5h13m	22h32m	23h22m	1h18m	4h23m	0.67
2020-07-29	4h25m	5h15m	22h31m	23h20m	1h49m	4h25m	0.77
2020-07-30	4h27m	5h16m	22h29m	23h18m	2h27m	4h27m	0.86
2020-07-31	4h29m	5h18m	22h28m	23h16m	3h11m	4h29m	0.93

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
Jul 1  We            Venus: 34.3° W
    3  Fr  11:18 pm  Moon Descending Node
    4  Sa  10:59 am  Aphelion: 1.0167 AU
    4  Sa  09:37 pm  Moon South Dec.: 24.1° S
    5  Su  12:30 am  Penumbral Lunar Eclipse
	                    (Americas, sw Europe, Africa)
    5  Su  12:44 am  Full Moon
    5  Su  05:37 pm  Moon-Jupiter: 1.9° N
    6  Mo  04:45 am  Moon-Saturn: 2.6° N
   11  Sa  08:17 am  Venus-Aldebaran: 1° N
   11  Sa  03:36 pm  Moon-Mars: 2.2° N
   12  Su  03:27 pm  Moon Apogee: 404200 km
   12  Su  07:29 pm  Last Quarter
   14  Tu  03:03 am  Jupiter Opposition
   17  Fr  03:26 am  Moon-Venus: 3.4° S
   18  Sa  08:33 am  Moon Ascending Node
   19  Su  07:51 am  Moon North Dec.: 24.1° N
   20  Mo  01:33 pm  New Moon
   20  Mo  05:33 pm  Saturn Opposition
   22  We  10:59 am  Mercury Greatest Elongation: 20.1° W
   25  Sa  12:54 am  Moon Perigee: 368400 km
   27  Mo  08:32 am  First Quarter
   27  Mo  05:08 pm  Delta Aquarid Meteor Shower: ZHR = 20
   31  Fr  05:32 am  Moon Descending Node
Aug 1  Sa            Venus: 45.2° 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

     LU                  Ephemeris of Sky Events for Interlochen/TC
July, 2020    Local time zone: EDT
+-----------------------------------------------------------------------+
| DATE |  SUN     SUN  DAYLIGHT|   TWILIGHT*    |MOON  RISE OR    ILLUM |
|      |  RISE    SET    HOURS |  END    START  |PHASE SET** TIME FRACTN|
+=======================================================================+
|Wed  1| 06:01a  09:31p  15:30 | 10:57p  04:35a |      Set  03:49a   87%|
|Thu  2| 06:01a  09:31p  15:29 | 10:56p  04:36a |      Set  04:29a   94%|
|Fri  3| 06:02a  09:31p  15:28 | 10:56p  04:37a |      Set  05:18a   98%|
|Sat  4| 06:03a  09:31p  15:27 | 10:55p  04:38a |      Set  06:15a  100%|
+------+-----------------------+----------------+-----------------------+
|Sun  5| 06:03a  09:30p  15:26 | 10:55p  04:39a |Full  Rise 10:19p   99%|
|Mon  6| 06:04a  09:30p  15:25 | 10:54p  04:40a |      Rise 11:02p   96%|
|Tue  7| 06:05a  09:29p  15:24 | 10:53p  04:41a |      Rise 11:37p   91%|
|Wed  8| 06:06a  09:29p  15:23 | 10:53p  04:42a |      Rise 12:05a   85%|
|Thu  9| 06:06a  09:29p  15:22 | 10:52p  04:43a |      Rise 12:30a   77%|
|Fri 10| 06:07a  09:28p  15:20 | 10:51p  04:44a |      Rise 12:52a   68%|
|Sat 11| 06:08a  09:27p  15:19 | 10:50p  04:45a |      Rise 01:12a   59%|
+------+-----------------------+----------------+-----------------------+
|Sun 12| 06:09a  09:27p  15:17 | 10:49p  04:46a |L Qtr Rise 01:33a   50%|
|Mon 13| 06:10a  09:26p  15:16 | 10:48p  04:47a |      Rise 01:55a   40%|
|Tue 14| 06:11a  09:25p  15:14 | 10:47p  04:49a |      Rise 02:19a   31%|
|Wed 15| 06:11a  09:25p  15:13 | 10:46p  04:50a |      Rise 02:47a   23%|
|Thu 16| 06:12a  09:24p  15:11 | 10:45p  04:51a |      Rise 03:20a   15%|
|Fri 17| 06:13a  09:23p  15:09 | 10:44p  04:52a |      Rise 04:01a    8%|
|Sat 18| 06:14a  09:22p  15:08 | 10:43p  04:54a |      Rise 04:52a    4%|
+------+-----------------------+----------------+-----------------------+
|Sun 19| 06:15a  09:21p  15:06 | 10:41p  04:55a |      Rise 05:52a    1%|
|Mon 20| 06:16a  09:21p  15:04 | 10:40p  04:56a |New   Set  09:45p    0%|
|Tue 21| 06:17a  09:20p  15:02 | 10:39p  04:58a |      Set  10:26p    2%|
|Wed 22| 06:18a  09:19p  15:00 | 10:38p  04:59a |      Set  11:01p    7%|
|Thu 23| 06:19a  09:18p  14:58 | 10:36p  05:00a |      Set  11:31p   14%|
|Fri 24| 06:20a  09:17p  14:56 | 10:35p  05:02a |      Set  11:58p   22%|
|Sat 25| 06:21a  09:16p  14:54 | 10:33p  05:03a |      Set  12:24a   33%|
+------+-----------------------+----------------+-----------------------+
|Sun 26| 06:22a  09:15p  14:52 | 10:32p  05:05a |      Set  12:50a   44%|
|Mon 27| 06:24a  09:13p  14:49 | 10:30p  05:06a |F Qtr Set  01:18a   55%|
|Tue 28| 06:25a  09:12p  14:47 | 10:29p  05:08a |      Set  01:49a   67%|
|Wed 29| 06:26a  09:11p  14:45 | 10:27p  05:09a |      Set  02:27a   77%|
|Thu 30| 06:27a  09:10p  14:42 | 10:26p  05:11a |      Set  03:11a   85%|
|Fri 31| 06:28a  09:09p  14:40 | 10:24p  05:12a |      Set  04:04a   92%|
+-----------------------------------------------------------------------+
* Nautical Twilight
** Moonrise or moonset, whichever occurs between sunrise and sunset

06/29/2020 – Vega, brightest star of the Summer Triangle

This is Ephemeris for Monday, June 29th. Today the Sun will be up for 15 hours and 31 minutes, setting at 9:32, and it will rise tomorrow at 6:00. The Moon, 1 day past first quarter, will set at 2:46 tomorrow morning.

Vega is the highest star In the east and brightest star of the Summer Triangle also rising in that direction. It is an important and much studied star, first as a standard for brightness for thr star brightness magnitude scale at magnitude of almost exactly zero. It also has two fields of debris orbiting it. In 1983 the Infrared Astronomy Satellite discovered an excess of infrared radiation coming from the star. It seems now that there are two orbiting rings, one warm, and the other cold orbiting the star. This is somewhat like the two disks the Sun has: The asteroid belt between Mars and Jupiter and the Kuiper belt, beyond Neptune. No planets have been discovered around Vega, but I wouldn’t bet against it.

The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Vega possesses two debris fields, similar to our own solar system’s asteroid and Kuiper belts. Astronomers continue to hunt for planets orbiting Vega, but as of May 2020 none have been confirmed. More info: bit.ly/VegaSystem Credit: NASA/JPL-Caltech.

Summer Triangle. Created using Stellarium.