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Ephemeris: 03/23/2026 – Looking out beyond the spring stars
This is Ephemeris for Monday, March 23rd. Today the Sun will be up for 12 hours and 19 minutes, setting at 7:59, and it will rise tomorrow at 7:38. The Moon, 2 days before first quarter, will set at 2:23 tomorrow morning.
It is becoming more obvious as the Moon waxes, that there’s more bright stars in the south and southwestern part of the sky than there are in the southeastern sky. That’s because the Milky Way runs through the winter part of the sky. It’s not as bright as the Milky Way appears in the summer since we are looking away from the center of our Galaxy. The disk of our galaxy causes stars to congregate near that Milky band, whether we can see it well or not. That is the main reason the winter stars are so bright. In the southeast we are looking at the spring sky. Leo the lion and of course the Great Bear with the Big Dipper are there, but we are mostly looking outside the disk or galaxy to the universe beyond. So we’re looking through fewer nearby stars, so the spring sky seems somewhat lackluster compared to the crazy chaos of the winter sky.
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; EST, UT – 5 hours) unless stated otherwise. Times will be different for other locations.
Addendum
Ephemeris: 09/15/2025 – Last month to view the southern Milky Way from Michigan
This is Bob Moler with Ephemeris for Monday, September 15th. Today the Sun will be up for 12 hours and 30 minutes, setting at 7:52, and it will rise tomorrow at 7:23. The Moon, 1 day past last quarter, will rise at 1:14 tomorrow morning.
September is the second of the two months we get to see the southern part of the Milky Way in the evening sky. At 10 PM the asterism of the Teapot of the constellation Sagittarius is pouring its tea on the southwestern horizon. It is in that direction that we look to the center of the Milky Way. Unfortunately there are clouds of dust and gas between us and the center, so we cannot see it visually, though it can be seen by radio waves and other means. There are a host of objects visible in binoculars and small telescopes. One does not need a star map to be able to find them, just point a telescope at low power or binoculars in that direction and sweep around slowly. There are treasures of star clusters and nebulae to be found.
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
In the image above the amount of detail of the stars is approximately that of a pair of binoculars. The various nebulae and star clusters are denoted with M numbers. These are some of the brightest, what we call deep sky objects, in the catalog by Charles Messier, who is looking for comets. He numbered them as he came across them. The brightest star cluster is M7, which Claudius Ptolemy recorded in the 2nd century CE. The brightest nebula is M8, the Lagoon Nebula out of which a star cluster is being formed. In binoculars, it looks like a short horizontal gash. Next in brightness is M17, a fuzzy spot in binoculars, but appears as a glowing check mark, or swimming swan in a telescope. M20, the Trifid Nebula, is the next brightest nebula in which dark dust lanes divide it into three lobes. M16, the Eagle Nebula is very dim. Most of the time I miss the nebulosity, but its embedded star cluster is quite easily seen. The rest of the Messier objects are star clusters or a star cloud. Of these M22 is a globular star cluster and one of the easiest of these clusters to resolve, though it might take a telescope of 150 mm (6″) diameter to do it.
Ephemeris: 08/21/2025 – The Milky Way’s Great Rift
This is Ephemeris for Thursday, August 21st. Today the Sun will be up for 13 hours and 45 minutes, setting at 8:38, and it will rise tomorrow at 6:53. The Moon, 2 days before new, will rise at 5:57 tomorrow morning.
Once one finds the Milky Way which is pretty hard to miss this month, it becomes obvious that the Milky Way is split lengthwise starting near Deneb, the northernmost star of the Summer Triangle, almost all the way to the Teapot of Sagittarius low in the south. That dark split is called the Great Rift. Galileo first discovered that the hazy clouds of the Milky Way were actually made of faint stars, so it was thought the dark areas were due to a lack of stars. The great 18th century astronomer William Herschel did star counts all over the sky with his telescope. A map his sister drew of the flattened shape of his universe shows the lack of distant stars in one direction. It’s not really fewer stars, but interstellar clouds of dust blocking the light of the stars behind them.
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
Ephemeris: 11/04/2024 – The Milky Way in Autumn
This is Ephemeris for Monday, November 4th. Today the Sun will be up for 10 hours and 1 minute, setting at 5:26, and it will rise tomorrow at 7:26. The Moon, 4 days past new, will set at 6:58 this evening.
As of yesterday the sunsets and sunrises have slipped back an hour so we have darker evenings and brighter mornings, as we came back to Standard Time. It seems odd that we spend less time of the year under Standard Time than we do under Daylight Time. Anyway, looking at the evening sky we see that Venus tonight will be above the four-day-old crescent Moon in the southwest after sunset. By 7 PM the northernmost star of the Summer Triangle, Deneb in Cygnus the swan or the Northern Cross, will be almost directly overhead. And the Milky Way at that time will run from northeast, overhead to the southwestern horizon. Remember tomorrow is Election Day. Make sure you cast your ballot before the end of voting tomorrow, if you haven’t already.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT – 5 hours). Times will be different for other locations.
Addendum
Ephemeris: 07/25/2024 – The Milky Way as it will appear tonight
This is Ephemeris for Thursday, July 25th. Today the Sun will be up for 14 hours and 54 minutes, setting at 9:16, and it will rise tomorrow at 6:23. The Moon, 2 days before last quarter, will rise at 11:43 this evening.
With the Moon out of the sky until almost 11:30 PM we get our first look at the summer Milky Way in the evening. The Milky Way will stretch from the east-northeast, high in the east to the South. The asterism of the stout little Teapot in Sagittarius, low to the south, is near the bottom end of the Milky Way. The milky stream appears as steam coming out of the spout. With more stars there, one might be able to see the Centaur with a bow and arrow. The front part of the teapot is the bow. The bottom left, and the far right star are the back and the tip of the arrow which is pointing at the heart of Scorpius the scorpion in the south-southwest. We’ll be exploring the wonders of the summer Milky Way this month and next.
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: 09/11/2023 – 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: 08/15/2023 – The Great Rift
This is Ephemeris for Tuesday, August 15th. Today the Sun will be up for 14 hours and 3 minutes, setting at 8:48, and it will rise tomorrow at 6:46. The Moon, 1 day before new, will rise at 6:41 tomorrow morning.
Once one finds the Milky Way which is pretty hard to miss this month, it becomes obvious that the Milky Way is split lengthwise starting near Deneb, the northernmost star of the Summer Triangle, almost all the way to the Teapot of Sagittarius low in the south. That dark split is called the Great Rift. Galileo first discovered that the hazy clouds of the Milky Way we’re actually made of faint stars, so it was thought the dark areas were due to a lack of stars. The great 18th century astronomer William Herschel did star counts all over the sky with his telescope. A map drawn of the shape of the Galaxy shows the lack of distant stars in the direction of the Great Rift. It’s not really fewer stars, but interstellar clouds of dust blocking the light of stars behind them.
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.
The span of the Milky Way across the summer sky as seen in the free Stellarium app. Specifically August 15th at 10 pm from Northern Michigan. The Milky Way has been set to its maximum brightness to show as much detail as possible. It really isn’t that bright. The horizon is only delineated by the compass points. The dark clouds of the Great Rift are also visible. The Milky Way, in Stellarium, is photo-realistic. The triangle of three bright stars above center is the Summer Triangle, Specifically, clockwise from the top star: Vega, Altair and Deneb. Large images can be truncated on the right. Click or tap on the image to enlarge and display the complete image.
William Herschel’s vision of the cross-section of the Milky Way from 1785, drawn by his sister and collaborator, Caroline Herschel. The Great Rift is seen as the gap between the fingers of stars on the right. Herschel thought the rift was caused by a lack of stars. Other than that, he got the flattened shape right, for what he could see within ten thousand light years. The center of the Milky Way lies 27,000 light years to the right. The spiral structure of the Milky Way wasn’t determined until the advent of radio telescopes in the mid-twentieth century.
Ephemeris: 08/14/2023 – August is the month to explore the Milky Way
This is Ephemeris for Monday, August 14th. Today the Sun will be up for 14 hours and 6 minutes, setting at 8:50, and it will rise tomorrow at 6:44. The Moon, 2 days before new, will rise at 5:35 tomorrow morning.
Now is the time the summer Milky Way is displayed to its fullest to the southern horizon. We have a week and a half before the Moon begins to encroach on our dark skies after 10 pm. City folk come to our area and are sometimes fooled by the brightness and expanse of the Milky Way and think it’s a cloud. Yes, those are clouds indeed, but they are clouds of stars. Binoculars will begin to show them to be millions of stars, each too faint to be seen individually to the eye, but whose combined glow give the impression of a luminous cloud. Binoculars are the ideal tool to explore the Milky Way. Objects still too fuzzy can be checked out with a telescope to reveal their true nature. The dark nights of August and September are my favorites.
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 span of the Milky Way across the summer sky as seen in the free Stellarium app. Specifically August 15th at 10 pm from Northern Michigan. The Milky Way has been set to its maximum brightness to show as much detail as possible. It really isn’t that bright. The horizon is only delineated by the compass points. The dark clouds of the Great Rift are also visible. The Milky Way, in Stellarium, is photo-realistic. The triangle of three bright stars above center is the Summer Triangle, Specifically, clockwise from the top star: Vega, Altair and Deneb. Large images can be truncated on the right. Click or tap on the image to enlarge and display the complete image.
08/25/2022 – Ephemeris – Looking to the heart of the Milky Way
This is Bob Moler with Ephemeris for Thursday, August 25th. Today the Sun will be up for 13 hours and 34 minutes, setting at 8:31, and it will rise tomorrow at 6:58. The Moon, 2 days before new, will rise at 5:52 tomorrow morning.
Behind a dark cloud in the Milky Way, just above the spout of the teapot asterism or informal constellation that we see of the zodiacal constellation of Sagittarius, lies the very center of our Milky Way Galaxy. It cannot be seen in visible light, but can be detected with radio waves and infrared light that can penetrate the clouds of dust between. In 1932 Bell Laboratory physicist and radio engineer, Karl Jansky, discovered a source of radio static that came from that region of sky. It was subsequently given the designation Sagittarius A. It turns out that within that source there is an object called Sagittarius A* (Pronounced Sagittarius A Star), invisible in the near infrared, but with the mass of four million suns. It was recently imaged as the black hole at the center of our galaxy.
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
Our place in the Milky Way. Note that we appear to be in a barred spiral galaxy. The arms are numbered and named. 3kpc is the 3 kiloparsec arm. 3kpc = 9,780 light years. The Sun is about 27,000 light years from the center. Credit NASA and Wikimedia Commons, via EarthSky.org
Location of the center of the Milky Way and the Teapot of Sagittarius. It’s behind that dark cloud.
An image from the Chandra X-ray Telescope of the center of the Milky Way. SGR A or Sagittarius A is a radio source. SGR A*, pronounced Sagittarius A Star, is the 4 million solar mass black hole in the center of the Milky Way Galaxy. Credit NASA.
M87* size compared to Sagittarius A*. The size of a black hole is directly related to its mass. The asterisk * is pronounced “Star”. Credit: Event Horizon Telescope Collaboration.
The black hole images were reconstructed from data from 8 sub millimeter radio telescopes and arrays of the Event Horizon Telescope Collaboration. The telescopes were located from Greenland to the South Pole and From Hawai’i to Europe. The data from the telescopes, observing the black holes simultaneously, were combined to act like a single telescope with the diameter of the Earth in order to resolve the black holes.
08/18/2022 – Ephemeris – The Great Rift
This is Ephemeris for Thursday, August 18th. Today the Sun will be up for 13 hours and 54 minutes, setting at 8:43, and it will rise tomorrow at 6:49. The Moon, 1 day before last quarter, will rise at 12:02 tomorrow morning.
High overhead, the Milky Way is seen passing through the Summer Triangle of three bright stars. Here we find the Milky Way splits into two sections. The split starts in the constellation of Cygnus the Swan or Northern Cross very high in the east. The western part of the Milky Way ends southwest of Aquila the eagle. This dark dividing feature is called the Great Rift. Despite the lack of stars seen there, it doesn’t mean that there are fewer stars there than in the brighter patches of the Milky Way. The rift is a great dark cloud that obscures the light of the stars behind it. Sometimes binoculars can be used to find the edges of the clouds of the rift, as star numbers drop off suddenly. This is especially easily seen in Aquila.
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 Great Rift finder animation as seen in the Summer Triangle, also showing the constellations of Cygnus the swan and the northern part of Aquila the Eagle. This image a stack of 5 30 second exposures taken the morning of the Perseid meteor shower the is year in a vain attempt to capture some meteors.
Bob Moler's Ephemeris Blog 