Ephemeris: 10/03/2023 – How to find Cassiopeia the queen

This is Bob Moler with Ephemeris for Tuesday, October 3rd. Today the Sun will be up for 11 hours and 36 minutes, setting at 7:19, and it will rise tomorrow at 7:44. The Moon, 3 days before last quarter, will rise at 9:35 this evening.

The stars of the autumn skies are slowly replacing the summer stars from the east. By 9 pm Scorpius the scorpion is gone, The Teapot asterism of Sagittarius is pouring its tea on the southwestern horizon. Looking halfway up in the northeastern sky these autumn the evenings one can find the letter W shaped constellation of Cassiopeia the queen. Cassiopeia is so far north that it never sets for us in Michigan. It is opposite the pole star Polaris from the handle of Big Dipper. Above and left of Cassiopeia is a dim upside down church steeple shaped constellation of Cepheus the king, her husband.

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

Cassiopeia and Cepheus finder animation looking in the northeast in the early evening. Also labeled is Delta Cephei. Created using Stellarium and GIMP.

Delta Cephei is the archetype for the important Cepheid variable stars that are used in distance measurement as far as the nearest galaxies. Delta itself varies its brightness from magnitude 4.37 up to 3.48. In astronomy the lower the magnitude the brighter the star. The difference of 0.89 magnitude equals a difference in brightness of 2.27 times. Delta has a pulsation period of 5.367 days. For Cepheids, the longer the period the brighter the star.

Ephemeris: 08/07/2023 – Sagittarius, centaur or teapot?

This is Bob Moler with Ephemeris for Monday, August 7th. Today the Sun will be up for 14 hours and 25 minutes, setting at 9:00, and it will rise tomorrow at 6:36. The Moon, 1 day before last quarter, will rise at 12:06 tomorrow morning.

Looking due south and low in the sky at 11 pm, now is one of my favorite asterisms, the Teapot of the constellation Sagittarius. Sagittarius, classically, represents a centaur with a bow and arrow aimed at the heart of the constellation Scorpius to its west. I can find the bow and arrow here, but the half man, half horse figure of the centaur eludes me. However, the stout little teapot of the children’s song is quite obvious, with its base, lid on top, handle to the left and the spout to the right. To make things more realistic, the bright Milky Way seems to rise like steam from its spout. The Teapot is an asterism, an informal constellation. As the night goes on, the Teapot moves westward and appears to tilt, pouring its tea on the southwestern horizon.

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

Sagittarius-Teapot finder animation for 11 pm, August 7, 2023. I’ve omitted all the lines in Sagittarius except the teapot stars from Stellarium, so there are more lines connecting the stars, most too far south to really spot easily from our latitude (45 degrees north). Click or tap on the image to enlarge it. Created using Stellarium and GIMP.

Named stars that are shown in the image above are Nunki, from an ancient tablet of thirty stars – The proclaimer of the sea. This is because the next four constellations to the east are water constellations: Capricornus, the sea goat; Aquarius, the water bearer; Pisces the fish; and Piscis Australis, the southern fish. Antares, in Scorpius, is of course the Rival of Mars, due to its reddish hue, and Mars passes Antares regularly on its journey through the Zodiac. An archer has to have his bow. Kaus Australis is the southern bow star. The star above that is Kaus Media, the middle bow star. And the star above and left of that is Kaus Borealis, the northern bow star. The constellation art that comes with Stellarium doesn’t match up with the stars of the bow.

The five stars on the left side of the Teapot is another asterism called the Milk Dipper.

Sagittarius in a short time exposure with added annotations. This would be later in the evening, around midnight. The “M” designations are objects in Charles Messier’s catalog created in the latter half of the 18th century. LSSC is the Large Sagittarius Star Cloud, SSSC is the Small Sagittarius Star Cloud. These will be easily visible in binoculars. Credit Bob Moler.

07/13/2023 – Ephemeris – How to find Ophiuchus the serpent bearer

This is Ephemeris for Thursday, July 13th. Today the Sun will be up for 15 hours and 17 minutes, setting at 9:27, and it will rise tomorrow at 6:10. The Moon, halfway from last quarter to new, will rise at 3:04 tomorrow morning.

The red star Antares shines in the south at 11 p.m. In the constellation of Scorpius. In the area of sky above and a little 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-like a weight lifter pulling up a heavy barbell. 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, now rising below and left of him.

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

Ophiuchus finder animation for July 13th at 11 pm. Obviously, the image I conjured up doesn’t quite match the constellation art that is part of Stellarium, but that’s the fun of seeing the sky your way. Created using Stellarium and GIMP.

08/16/2022 – Ephemeris – Scanning Sagittarius with binoculars

This is Bob Moler with Ephemeris for Tuesday, August 16th. Today the Sun will be up for 14 hours to the minute, setting at 8:46, and it will rise tomorrow at 6:47. The Moon, 3 days before last quarter, will rise at 11:15 this evening.

The Moon has left the evening sky, so let’s take another look at the constellation of Sagittarius. Its bright stars make a follow the dots image of a stout little teapot. In, around and above the teapot is a wealth of nebulae, which are clouds of gas and dust and clusters of stars. Stars are born in bunches from a cloud of gas. When enough stars are born, their stellar winds blow away the nebulosity leaving a star cluster. Use a pair of binoculars or a very low power telescope and just wander around and above the teapot, including and especially the spout on the right side. In binoculars, star clusters appear fuzzy like nebulae, however a small telescope with magnification of 20 times should resolve most of 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.

Addendum

Sagittarius in a short time exposure with added annotations. The “M” designations are objects in Charles Messier’s catalog created in the latter half of the 18th century. LSSC is the Large Sagittarius Star Cloud, SSSC is the Small Sagittarius Star Cloud. Labels are to the right of the objects they name. Credit Bob Moler.

This is the short radio program version of the August 8, 2022, Ephemeris Extra post Wandering through Sagittarius

Ephemeris Extra – Wandering through Sagittarius

Sagittarius in a short time exposure with added annotations. The “M” designations are objects in Charles Messier’s catalog created in the latter half of the 18th century. LSSC is the Large Sagittarius Star Cloud, SSSC is the Small Sagittarius Star Cloud. Credit Bob Moler.

Sagittarius is seen low in the south in August. It’s between Scorpius to the west, and Capricornus, rising in the southeast. The name Sagittarius simply means archer. It doesn’t describe the fact that the archer isn’t just any old bloke with a bow and arrow, but is, indeed, a centaur, one of the two in the list of constellations. The other, Centaurus, is too far south to be seen from Michigan. And whose brightest star, Alpha Centauri, is in the closest star system to our solar system.
Centaurs, as a rule, were a rowdy bunch, the ancient Greek equivalent to a modern motorcycle gang. However, the centaur depicted by Sagittarius can be thought to be Chiron, though it can also be ascribed to Centaurus. Chiron was learned, a teacher and physician. I’ve noticed that in some artist’s depictions of Chiron, he is teaching Achilles how to use the bow and arrow. He also taught medicine to Asclepius, the great physician, who is seen in the heavens as the constellation Ophiuchus, above and right of Sagittarius.
What most of us see in the stars here is maybe a bow drawn to shoot at the heart of Scorpius, or a stout little teapot as in the children’s song. It even has the Milky Way seeming to rise from the spout like steam. The teapot rises in the southeast as if standing upright, and as the night wears on, it rises and move westward, slowly tilting to pour out its tea on the southwestern horizon.
The area of Sagittarius and the Milky Way is a fantastic part of the sky to explore with binoculars or a low power telescope on moonless nights. At the head of this post is a photograph of Sagittarius and the Milky Way taken from my home, with lines and labels. It’s somewhat spoiled by the sky glow from Chum’s Corner, a small commercial center 3.6 miles away, from the lower left. Most binoculars will show open or galactic star clusters as fuzzy spots like nebulae, which are fuzzy because they are clouds. The older globular star clusters require larger amateur telescopes to resolve.
I’ve only pointed out one in the image, that’s M22, whose designation, we have fun with at star parties at the Sleeping Bear Dunes National Lakeshore, since the road M22 runs through the park. Which came first? That’s easy, Charles Messier cataloged his 22nd object before Michigan was a state or even had roads. Well, maybe there were a few, around Detroit and Sault Ste. Marie, back when the major “roads” were the Great Lakes, and the rest Indian trails.
A telescope, even a small one, will resolve open clusters, showing individual stars. Telescopes will show the shapes of nebulae if they are bright enough.
One nebula with a distinctive shape is M17. The descriptive name I first knew it as was the Omega Nebula, and also the Horseshoe Nebula. To me, it never looked like either. It looked like a check mark, or a somewhat short necked swan. And it also goes by those names too. The planetarium program I use a lot, Stellarium, also calls it the Lobster nebula. I’m not much for seafood, but it doesn’t look like a lobster, or maybe I’m not hungry enough.
M16, is the Eagle Nebula. It has an associated star cluster. My eyes are drawn to the star cluster. The nebulosity is very faint, and I usually can’t see it. Part of the nebula was famously photographed by the Hubble Space Telescope and called the Pillars of Creation. In actuality, they are the Pillars of Destruction as they are being blown away by the stellar winds of the star cluster.
M8 is the Lagoon Nebula, it also has an associated star cluster. In telescopes, it is crossed by a narrow dust cloud suggestive of a lagoon. Nearby M20 is the Trifid nebula, which has a low surface brightness and can easily be missed. It is crossed by three narrow dust clouds dividing it into three, or on closer inspection, four wedges.
These just scratch the surface. So with or without optical aid wander through the celestial wonders and star clouds of Sagittarius. You have August and September to do it in the evening before they set for another year.

Based on an article I wrote for the August 2022 issue of the Stellar Sentinel, the Newsletter of the Grand Traverse Astronomical Society.

07/19/2022 – Ephemeris – How to find the constellations of the man with the snake

This is Ephemeris for Tuesday, July 19th. Today the Sun will be up for 15 hours and 7 minutes, setting at 9:22, and it will rise tomorrow at 6:16. The Moon, 1 day before last quarter, will rise at 12:52 tomorrow morning.

The red star Antares shines in the south at 11 pm, in the constellation of Scorpius. In the area of sky above lies a large constellation of faint stars called Ophiuchus, the serpent bearer. The constellation shape is like a large tilted bell, which reminds me of the head, shoulders and arms of a fellow that’s holding the snake, like a weight lifter pulling up a heavy barbell. 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 legend Ophiuchus represents a great physician, educated by the god Apollo, and the centaur Chiron, who is also found in the stars as Sagittarius, now rising in the south-southeast below and left of him.

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

Ophiuchus finder animation for mid-July at 11 pm. Created using Stellarium and GIMP.

08/05/2021 – Ephemeris – Looking toward the center of the Milky Way in Sagittarius

This is Ephemeris for Thursday, August 5th. Today the Sun will be up for 14 hours and 29 minutes, setting at 9:02, and it will rise tomorrow at 6:35. The Moon, 3 days before new, will rise at 4:09 tomorrow morning.

Let’s look around the Teapot shape of stars that is the constellation of Sagittarius. A pair of binoculars or a telescope with a very low magnifying power is all that’s needed. The purpose here is not so much to make things bigger, but make them brighter. Right off the tip of the teapot’s spout is a large and bright patch of light. This is the farthest we can see, in visible light that is, toward the center of our galaxy, part of the central bulge. Astronomer Walter Baade discovered that fact in the mid 1940s. The center of the galaxy is 4 moon-widths or 2 degrees to the right of it, but obscured by a cloud of interstellar dust. It is called the Large Sagittarius Star Cloud or Baade’s Window. The glow there comes from 25 thousand light years away.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.

Addendum

Baade’s Window, aka Large Sagittarius Star Cloud. A finder animation created from my photograph taken August 23, 2016, at 11:23 pm. Click on the image to enlarge it.

08/03/2021 – Ephemeris – Centaur or Teapot?

This is Ephemeris for Tuesday, August 3rd. Today the Sun will be up for 14 hours and 33 minutes, setting at 9:05, and it will rise tomorrow at 6:32. The Moon, 3 days past last quarter, will rise at 2:31 tomorrow morning.

In the south and low in the sky at 10:30 p.m. is one of my favorite asterisms the Teapot of the constellation Sagittarius. Sagittarius classically represents a centaur with a bow and arrow aimed at the heart of the constellation Scorpius to its west. I can find the bow and arrow here, but the half man, half horse figure of the centaur eludes me. However, the stout little teapot of the children’s song is quite obvious, with its base, lid on top, handle to the left and the spout to the right. To make things more realistic, the bright Milky Way seems to rise like steam from its spout. As the night goes on, the Teapot slides westward and appears to tilt, pouring its tea on the southwestern horizon. Its appearance in the south is an invitation to explore the milky band with binoculars.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT – 4 hr). They may be different for your location.

Addendum

Sagittarius and the Teapot finder animation for tonight, August 3rd. Created using Stellarium.

09/07/2020 – Ephemeris – A first look at the autumn stars arriving: Cassiopeia and Pegasus

This is Ephemeris for Labor Day, Monday, September 7th. Today the Sun will be up for 12 hours and 54 minutes, setting at 8:07, and it will rise tomorrow at 7:14. The Moon, 3 days before last quarter, will rise at 10:46 this evening.

In the evening as summer wanes and the Sagittarius teapot tips its contents on the southwestern horizon the constellations of autumn rise in the east. There’s the W shape of Cassiopeia in the northeast, which is so far north it never really leaves us in northern Michigan. Pegasus the flying horse of Greek mythology is perhaps the most famous of the autumn constellations, and easiest to find. Its body, a large square of four stars, is in the east, standing on one corner. It is known as the Great Square of Pegasus. Only the front half of the horse is in the sky, and he’s flying upside down with his neck and head extending to the right from the rightmost star. His galloping front legs extend upward from the top star.

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

Addendum

Northeast to southwest Panorama around the horizon at 10 pm tonight, September 7, 2020 showing the constellations discussed. Click on the image to enlarge. Created using Stellarium and GIMP.

 

08/13/2020 – Ephemeris – Sagittarius the archer, morphs into a teapot

This is Bob Moler with Ephemeris for Thursday, August 13th. Today the Sun will be up for 14 hours and 7 minutes, setting at 8:50, and it will rise tomorrow at 6:44. The Moon, 2 days past last quarter, will rise at 1:53 tomorrow morning.

Due south and low in the sky at 10:30 p.m. now is one of my favorite asterisms the Teapot of the constellation Sagittarius. Sagittarius classically represents a centaur with a bow and arrow aimed at the heart of the constellation Scorpius to its west. I can find the bow and arrow here, but the half man half horse figure of the centaur eludes me. However the stout little teapot of the children’s song is quite obvious, with its base, lid on top, handle to the left and the spout to the right. To make things more realistic the bright Milky Way seems to rise like steam from its spout. As the night goes on the Teapot slides westward and appears to tilt, pouring its tea on the southwestern horizon. Jupiter and Saturn are just to the left of it now.

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

Addendum

Sagittarius-Teapot finder animation for 10 pm August 13, 2020. Click on the image to enlarge. Created using Stellarium and GIMP.