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Ephemeris: 06/26/2025 – Finding the famous Double-Double Star

June 26, 2025 Comments off

This is Ephemeris for Thursday, June 26th. Today the Sun will be up for 15 hours and 33 minutes, setting at 9:32, and it will rise tomorrow at 5:59. The Moon, 1 day past new, will set at 11:12 this evening.

I generally will talk about observing something in the sky, in this program, if it can be seen with the naked eye, or can be seen in binoculars near something that can be seen with the naked eye, or something that can be seen in a small telescope that is visible in binoculars, near a naked eye object. This is of the latter type. High in the east at 11:00 PM or so is the bright star Vega. Just to the left of it in is a faint star, best seen in binoculars. It’s barely visible to the naked eye as a single star. But binoculars will show that it’s two star of equal brightness. However, viewing it with a telescope using probably the most power the telescope is capable, each of those stars is doubled again so Epsilon Lyrae is the famous Double-Double Star. It’s quite a challenge for a small telescope. This is also the time of the latest sunset and end of evening twilight. The last vestige of the glow moves to the north and ends just after midnight.

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

Lyra finder, animated
Finding Lyra the harp in late June, looking east to the summer triangle – 3 frames. 1st, the stars of the Summer Triangle and others as they would be seen while looking eastward. 2nd, the star names of the Summer Triangle stars, and the lines for the constellation Lyra. 3rd, an image of a tortoiseshell harp placed on the constellation. Created using Stellarium, LibreOffice Draw, and GIMP.
Lyra, magnified to the level found with binoculars, showing Epsilon Lyrae.
Lyra, magnified to the level found with binoculars, showing Epsilon Lyrae. The star shows a cleaner split than seen here.
Bonus: A telescope capable of splitting the components of Epsilon should be capable of spotting the Ring Nebula (M57). It is not, however, visible in binoculars or a telescope finder. But it’s easily found by pointing the telescope between the two bottom stars of the Lyra parallelogram. Created using Stellarium, LibreOffice Draw and GIMP.
A drawing of the resolved components of Epsilon Lyrae as seen in a telescope by Jeremy Perez.
A drawing of the resolved components of Epsilon Lyrae as seen in a telescope by Jeremy Perez.
Photograph of M57, the Ring Nebula
Photograph of M57, the Ring Nebula. Visually, the nebula is much dimmer and colorless. Our eye’s sacrifice color vision at very low light levels. This is what a sunlike star does near the end of its life by blowing off its outer layers as it settles down to being a white dwarf. Credit: Daniel Dall’Olmo.

Ephemeris: 06/25/2025 – Taking our weekly look at the naked-eye planets

June 25, 2025 Comments off

This is Ephemeris for Wednesday, June 25th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:32, and it will rise tomorrow at 5:58. The Moon is new today, and won’t be visible.

Let’s take our weekly look at the whereabouts of the naked-eye planets. The Red Planet Mars, will be seen to the upper left of the bright star Regulus in the constellation Leo the lion. Both are seen in the western sky by 10:30 PM at least. At that time Mercury might be spotted low on the west-northwestern Lake Michigan horizon. This is not a favorable appearance of Mercury. Jupiter passed conjunction with the Sun yesterday, but it will be nearly a month before it will appear in our morning sky. Venus will rise at 3:34 AM in the east northeast, and by 5 AM will be seen low in the east, as the Morning Star. By then Saturn will be in the southeast, having risen 2 hours earlier.

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

Mars and Regulus this evening with Mercury and other bright stars in the western sky near 10:30 PM.
Mars and Regulus this evening with Mercury and other bright stars in the western sky near 10:30 PM, June 25, 2025. Mercury is seen here, but will probably be invisible from my latitude as being too low in the sky. The farther south one goes, at least to the equator, the higher Mercury will appear. Created using Stellarium.
Venus and Saturn at 5 AM tomorrow morning

Venus and Saturn at 5 AM tomorrow morning, June 26th, 2025, in the east-southeastern sky. Created using Stellarium.
Telescopic Saturn and Venus
Telescopic Saturn and Venus (north up) as they would be seen in a small telescope with the same magnification. On the evening of June 25, 2025, Mercury will have an apparent diameter of 7.0″ and be 54.9% illuminated. Mars will be 5.0″ in diamete. Both are too small to be shown here. My lower size limit is 10″. On the morning of the 26th, Saturn will be 17.6″ in diameter, but its rings, being nearly edge on, should show up brighter than seen here., and extend to 40.9″. They are tilted 3.4° from being edge on. Venus’ apparent diameter will be 18.5″, and be 61.7% illuminated. The ” 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 June 25, 2025. The night ends on the left with sunrise on the 26th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.
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, June 25th and 26th, 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.

Ephemeris: 6/24/2025 – Lyra, the heavenly harp

June 24, 2025 Comments off

This is Ephemeris for Tuesday, June 24th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:32, and it will rise tomorrow at 5:58. The Moon, 1 day before new, will rise at 5:36 tomorrow morning.

Fairly 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 nighttime star. To the Romans, the star Vega represented a falling eagle or vulture. Apparently they never made the distinction between the two species. It is a pure white star and serves as a calibration star for color and brightness. In the evening, it is the top-most star of the Summer Triangle. 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 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

Lyra finder multi-frame
Finding Lyra the harp in late June, looking east to the summer triangle – 3 frames. 1st, the stars of the Summer Triangle and others as they would be seen while looking eastward. 2nd, the star names of the Summer Triangle stars, and the lines for the constellation Lyra. 3rd, an image of a tortoiseshell harp placed on the constellation. Created using Stellarium, LibreOffice Draw, and GIMP.

Ephemeris: 06/23/2025 – The Big Dipper is tearing itself apart

June 23, 2025 Comments off

This is Ephemeris for Monday, June 23rd. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:32, and it will rise tomorrow at 5:58. The Moon, 2 days before new, will rise at 4:33 tomorrow morning.

The usual impression is to think that the stars of a constellation are actually located close together. This is usually not true. The stars of a constellation can be at vastly different distances. The Big Dipper is different. The five stars, excepting the two end stars of the dipper and 12 other dimmer stars in the general area are of similar distance and have the same motion through space. The group is called the Ursa Major Moving Cluster or Ursa Major Association, and is moving about 9 miles per second relative to the solar system to the east. An association is a rather loose, sparse star cluster. This association lies about 80 light years away. If it were five and a half times farther away, it would be the same distance as the Pleiades.

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

50,000 year proper motion of the Big Dipper stars.
50,000 year proper motion of the Big Dipper’s stars.
The Big Dipper 50,000 years from now.
The Big Dipper 50,000 years from now.

Ephemeris: 06/20/2025 – Summer begins tonight!

June 20, 2025 Comments off

This is Ephemeris for Friday, June 20th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:31, and it will rise tomorrow at 5:57. The Moon, 2 days past last quarter, will rise at 2:38 tomorrow morning.

Summer will officially arrive for us on Earth’s Northern Hemisphere at 10:42 pm, tonight. If you are south of the equator, winter will arrive. If you are listening to this on the Internet from two time zones east of the Eastern United States it’s 2:42 UT, June 21st. And to be season agnostic, it’s the June solstice. From tonight to the December solstice, the first day of winter for us northern hemispherians, (I think that’s a word) the daylight hours will get shorter as the Sun heads south. Solstice means “Sun standstill” as it stops its northerly motion and will, after tonight, head back south again. The Northern Hemisphere will still be heating up for another month, before we begin to cool down.

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

Solstices
Comparing the sun’s path at the summer and winter solstices. This is a stereographic representation of the whole sky which distorts the sky and magnifies the size of the sun’s path near the horizon. This is a stereographic projection, which compresses the image near the zenith. Created using my LookingUp app.
Earth and local area near summer solstice from NOAA's DSCOVR satellite orbiting the Sun-Earth L1 point.
Earth and magnified local area near summer solstice. Image taken near local noon June 17, 2020. Credit: NOAA’s DSCOVR satellite orbiting the Sun-Earth L1 point 994,970 miles (1,601,432 kilometers) sunward from the Earth.

Ephemeris: 06/19/2025 – Finding the Serpent Bearer in the heavens

June 19, 2025 Comments off

This is Ephemeris for Juneteenth, Thursday, June 19th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:31, and it will rise tomorrow at 5:57. The Moon, 1 day past last quarter, will rise at 2:15 tomorrow morning.

The red star Antares shines low in the south-southeast at 11 PM in the constellation of Scorpius. In the area of sky above and to the left lies a large constellation of faint stars called Ophiuchus, the serpent bearer. The constellation shape is like a large bell, which reminds me of the head, shoulders and arms of a fellow that’s holding the snake stretched out across his body. The serpent he’s holding is Serpens, the only two-part constellation in the heavens. The head rises to Ophiuchus’ right, and the tail extends up to the left. In Greek myth, Ophiuchus represents the great physician Aesculapius, educated by the god Apollo, and the centaur Chiron, who is found in the stars as Sagittarius, just rising below him.

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

Ophiuchus finder chart in three frames
An Ophiuchus finder chart in three frames: showing first, the stars as one would see it in the night sky; second, the constellation lines; and third, the constellation art from Stellarium. The location of the stars are for approximately 11 PM. Created using Stellarium and GIMP.

Ephemeris: 06/18/2025 – Three of the five naked-eye planets are visible now

June 18, 2025 Comments off

This is Ephemeris for Wednesday, June 18th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:31, and it will rise tomorrow at 5:56. The Moon, at last quarter today, will rise at 1:55 tomorrow morning.

Let’s take our weekly look at the whereabouts of the naked-eye planets. The Red Planet Mars, will be seen just to the upper left of the bright star Regulus in the constellation Leo the lion. Both are seen in the western sky by 10:30 PM at least. They are currently about the same brightness, but Mars has an orange-reddish hue, while Regulus, is blue-white. They are a good color contrast, especially in binoculars which will increase their brightness. Even before 5 AM Venus will be seen very low in the east, as the Morning Star. The waning crescent Moon will be near Saturn, having passed it around midnight. By 5 AM Saturn will be to the right and below it. Venus will be visible until close to 5:40.

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

Mars and Regulus this evening with other bright stars in the western sky near 10:30 PM
Mars and Regulus this evening with other bright stars in the western sky near 10:30 PM, June 18, 2025. Mercury is seen here, but will probably be invisible from my latitude. The farther south one goes, at least to the equator, the higher Mercury will appear. Created using Stellarium and LibreOffice Draw for the captions.
Venus, Saturn and the waining crescent Moon at 5 AM tomorrow morning

Venus, Saturn and the waining crescent Moon at 5 AM tomorrow morning, June 19th, 2025, in the east. Created using Stellarium.
The Moon just 14 hours after last quarter. Selected features are labeled. Created using Stellarium, labels from Virtual Moon Atlas, added using LibreOffice Draw and GIMP.
Telescopic Saturn and Venus (north up) as they would be seen in a small telescope with the same magnification
Telescopic Saturn and Venus (north up) as they would be seen in a small telescope with the same magnification. On the evening of June 18, 2025, Mars is 5.1″ in diameter, too small to be shown here. My lower size limit is 10″. On the morning of the 19th, Saturn is 17.4″ in diameter, but its rings, being nearly edge on should show up brighter than seen here., and extend to 40.4″. They are tilted 3.5° from being edge on. Venus’ apparent diameter is 19.7″, and is 58.6% illuminated. The ” 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 June 18, 2025. The night ends on the left with sunrise on the 19th. 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, June 18th and 19th, 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.

Ephemeris: 06/17/2025 – Finding the naked-eye double star Mizar and Alcor

June 17, 2025 Comments off

This is Ephemeris for Tuesday, June 17th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:31, and it will rise tomorrow at 5:56. The Moon, 1 day before last quarter, will rise at 1:36 tomorrow morning.

In tonight’s sky, the Big Dipper is high in the northwest hanging from its handle. In its handle is a star or two that are fascinating. It’s the star at the bend in the handle. It’s called Mizar. Next to it, for those with good eyesight, is a dimmer star, called Alcor. The name Mizar is from the Arabic, meaning apron or cover, while Alcor means the forgotten one. In ancient times the ability to actually see both stars was a test for good eyesight, especially for Arabic warriors. The pair is also known as the “Horse and the Rider”. Some Native American tribes saw the handle stars as hunters tracking the Great Bear, Ursa Major, of which the Big Dipper is a part, rather than its very unnatural tail. Dim Alcor became a hunting dog.

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 the Big Dipper at about 11 PM June 17th, high in the northwestern sky, showing the location of Mizar at the bend of the handle with its companion Alcor. Created using Stellarium, annotations with LibreOffice Draw, and GIMP.
A telescopic view of Mizar in Alcor
Here is a telescopic view of Mizar in Alcor. Note that Mizar is again a binary star. Its components A and B, A being the brighter of the two. Binoculars can’t quite split Mizar but it can be done with a small telescope. The dim star between the two is a background star about 300 light years away compared to Mizar and Alcor’s 81 light year distance. Created using Stellarium, annotations with LibreOffice Draw, and GIMP.

Ephemeris: 06/16/2025 – Mars meets Regulus tonight

June 16, 2025 Comments off

This is Ephemeris for Monday, June 16th. Today the Sun will be up for 15 hours and 34 minutes, setting at 9:30, and it will rise tomorrow at 5:56. The Moon, 2 days before last quarter, will rise at 1:17 tomorrow morning.

If one looks out tonight to the west after dark, two bright stars will appear very close together. One appears to the upper right of the other and very close, about one and a half moon-widths apart. The star to the upper right will have a reddish hue. It’s not a star at all but the planet Mars. The other one is a star, Regulus in Leo the lion. After tonight Mars will continue its trek eastward against the stars heading towards another bright star, Spica in Virgo. It will pass north of that star on September 11th. Mars will pass any particular star near the ecliptic on the average of one year, ten and a half months, which is its orbital period of the Sun. Since we’re viewing it from the moving Earth, along with Mars’ eccentric orbit, the interval can vary greatly.

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 conjunction of the planet Mars and the star Regulus in Leo the lion as it might be seen at 10:30 PM tonight, June 16th 2025, low in the West after sunset. Mars is very nearly the same brightness as Regulus, but they have very different colors. Regulus is blue-white, while Mars has a reddish hue. Mars is moving to the upper left against the stars, but both Regulus and Mars are losing their fight against the Sun due to the Earth’s orbital motion around it. However, Mars will linger longer in the evening sky. Created using Stellarium, LibreOffice Draw, and GIMP.

Ephemeris: 06/13/2025 – Finding the Summer Triangle

June 13, 2025 Comments off

This is Ephemeris for Friday, June 13th. Today the Sun will be up for 15 hours and 32 minutes, setting at 9:29, and it will rise tomorrow at 5:56. The Moon, 2 days past full, will rise at 11:59 this evening.

Summer skies are coming. It’s only 7 days until summer officially arrives. Looking to the eastern sky at 11 pm are three of the brightest stars in a large triangle. The top star Vega is about halfway up the sky to the zenith, and the brightest of the three. It’s in the small constellation of Lyra the harp. Lowest of the stars and just about due east is Altair in Aquila the eagle. Completing the triangle is Deneb in the northeast in the tail of Cygnus the swan or the head of the horizontal Northern Cross. These three stars make up the Summer Triangle, which isn’t an official constellation. It’s one of the many informal star patterns called asterisms. The Summer Triangle will be in our evening sky moving slowly westward until December.

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

Finder animation for the Summer Triangle
Finder animation for the Summer Triangle, seen in red for 11 pm, in early June. Created using Stellarium and GIMP.