Archive
07/18/2022 – Ephemeris – How to find the celestial eagle
This is Bob Moler with Ephemeris for Monday, July 18th. Today the Sun will be up for 15 hours and 8 minutes, setting at 9:23, and it will rise tomorrow at 6:15. The Moon, 2 days before last quarter, will rise at 12:33 tomorrow morning.
Aquila the eagle is a constellation that lies in the Milky Way. It’s in the southeastern sky as it gets dark. Its brightest star, Altair, is one of the stars of the Summer Triangle, a group of three bright stars that dominate the eastern sky in the evening now. Altair, in the head of the eagle, is flanked by two slightly dimmer stars, the shoulders of the eagle. The eagle is flying northeastward through the Milky Way. Its wings are seen in the wing tip stars. A curved group of stars to the lower right of Altair is its tail. Within Aquila, the Milky Way shows many dark clouds as part of the Great Rift that splits it here. The other summer bird is Cygnus the swan above and left of Aquila, flying toward the eagle.
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
Animated Aquila finder chart, also showing Cygnus the swan. The named stars are the stars of the Summer Triangle. Created using Stellarium.
Annotated and animated photograph taken of Aquila August 13, 2018 during the Perseid meteor shower. Alas, no Perseids in this photograph. The clouds of the Great Rift are easily visible. The red tinge of the image was due to the smoke haze from the wildfires in the western states. Taken by me and processed using Registax and GIMP.
07/09/2021 – Ephemeris – Finding the constellation of Aquila the eagle
This is Ephemeris for Friday, 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 is new today, and won’t be visible.
Aquila the eagle is a constellation that lies in the Milky Way. It’s in the southeastern sky as it gets dark. Its brightest star, Altair, is one of the stars of the Summer Triangle, a group of three bright stars dominating the eastern sky in the evening now. Altair, in the head of the eagle, is flanked by two slightly dimmer stars, the shoulders of the eagle. The eagle is flying northeastward through the Milky Way. Its wings are seen in the wing tip stars. A curved group of stars to the lower right of Altair is its tail. Within Aquila, the Milky Way shows many dark clouds as part of the Great Rift that splits it here. The other summer bird is Cygnus the swan above and left of Aquila, flying in the opposite direction. It was said this was the eagle that attended the god Jupiter.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT-4). They may be different for your location.
Addendum
Animated Cygnus finder chart. Lyra the harp, Cygnus the swan, Delphinus the dolphin and Sagitta the arrow are also in the image. Can you find them? Click on the image to enlarge it. Created using Stellarium and GIMP.
07/08/2021 – Ephemeris – How to find the constellation of Cygnus the swan
This is Ephemeris for Thursday, 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, 1 day before new, will rise at 5:23 tomorrow morning.
Halfway up the sky in the east at 11 pm 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 to the 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, a beautiful double star in telescopes, 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 for a couple more stars each side.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT-4). 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.
08/21/2020 – Ephemeris – Great moments in astronomy: The Great Debate in 1920
This is Bob Moler with Ephemeris for Friday, August 21st. Today the Sun will be up for 13 hours and 44 minutes, setting at 8:37, and it will rise tomorrow at 6:54. The Moon, 3 days past new, will set at 10:26 this evening.
One hundred years ago there were two lectures given to the National Academy of Science by Drs. Harlow Shapley and Heber Curtis. This became know as the Great Debate. Shapley believed that the Milky Way was the entire universe, and evidenced by the distribution of globular star clusters in the sky that the Sun was near the periphery of it, and that spiral nebulae were part of the Milky Way. Curtis on the other hand thought that the Sun was near the center of the Milky Way, however that the spiral nebulae were other island universes, or milky ways of their own. Over the next decade each was proved right in part and wrong in part. We are not near the center of the Milky Way, but those spiral nebulae were indeed other milky ways or galaxies.
The event times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
A drawing of the Whirlpool Galaxy, M51 (NGC 5194 & 5195) by Lord Rosse with his 72 inch telescope in the mid 19th century. This is the only “spiral nebula” I have actually seen as a spiral visually in a telescope, though not as well as he saw it. Public Domain.
With the advent of photography many spiral nebulae were discovered. The Whirlpool Galaxy, M51. Credit Scott Anttila.
This is a copy of the Press release issued for the two presentations of Harlow Shapley and Heber Curtis at the annual meeting of the National Academy of Sciences April 26, 1920 that have come to be known as the “Great Debate”. Credit NAS.
For more on the Great Debate follow this link.
Astronomy has advanced a long way in the last 100 years. And what’s crazy is that I actually met Dr. Harlow Shapley at the opening of the Planetarium of the Grand Rapids Public Museum around 1960. I was in my first year at Grand Rapids Junior College at the time. I had been a member of the of the local astronomy club for several years by then. Two friends and I became planetarium rats and have wormed our way into volunteering to working with it before a formal structure was set up to operate it.
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.
08/26/2018 – Ephemeris – The Great Rift
Ephemeris for Monday, August 26th. Today the Sun will be up for 13 hours and 32 minutes, setting at 8:30, and it will rise tomorrow at 6:59. The Moon, 3 days past last quarter, will rise at 3:13 tomorrow morning.
High overhead the Milky Way is seen passing through the Summer Triangle of three bright stars. Here we find the Milky Way split 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 the 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 stars numbers drop off suddenly. This is especially easy to spot in Aquila the eagle.
The times given are for the Traverse City/Interlochen area of Michigan. 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 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.
Annotated and animated photograph taken of Aquila August 13, 2018 during the Perseid meteor shower. Alas, no Perseids in this photograph. Taken by me and processed using Registax and GIMP.
08/22/2019 – Ephemeris – Scanning the Milky Way in and around Sagittarius
Ephemeris for Thursday, August 22nd. Today the Sun will be up for 13 hours and 44 minutes, setting at 8:37, and it will rise tomorrow at 6:54. The Moon, 1 day before last quarter, will rise at 12:10 tomorrow morning.
Tuesday I talked about finding the teapot shaped asterism or informal shape in the stars where the constellation Sagittarius is. Once that is found, a pair of binoculars will help find many fuzzy wonders in the Milky Way here. Mostly we are looking at the next spiral arm in toward the center of the Milky Way galaxy. The star clusters and nebulae here are from 5,000 to 10,000 light years away, a good deal farther than the Great Orion Nebula we see in winter, which is much closer. We are also looking at a much brighter and more populous arm of the Milky Way than the one the Sun happens to be in. We are in a vast spiral galaxy whose center is 27,000 light years away beyond the star and dust clouds above the teapot’s spout.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The sky around Sagittarius and Scorpius at 10 p.m. August 22, 2019. The objects noted will appear as fuzzy objects in binoculars. Dotted circles are open or galactic star clusters which are easily resolved in small telescopes. Crossed circles are globular star clusters, which require larger telescopes to resolve. Squares are emission nebulae, bright clouds of gas, illuminated by the young stars born within them. Click on the image to enlarge. Created using Stellarium.
We call these objects Deep Sky Objects or DSOs. Unnamed objects are dimmer than named objects.
11/05/2018 – Ephemeris – Cassiopeia the Queen
Ephemeris for Monday, November 5th. The Sun will rise at 7:26. It’ll be up for 9 hours and 59 minutes, setting at 5:26. The Moon, 2 days before new, will rise at 6:00 tomorrow morning.
The stars of the autumn skies are replacing the summer stars from the east. Look in the northeastern sky by 7 p.m. and you can find the 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 Big Dipper. There’s a dim star that appears above the middle star of the W which turns it into a very crooked backed chair, Cassiopeia’s throne. Above and left of Cassiopeia is a dim upside down church steeple shaped constellation of Cepheus the king, her husband. The Milky Way flows through Cassiopeia toward the northeastern horizon and through the constellation of Perseus the hero, which kind of looks, to me anyway, like the cartoon roadrunner.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
07/21/2017 – Ephemeris – There’s an astronomy event tomorrow night
Ephemeris for Friday, July 21st. Today the Sun will be up for 15 hours and 2 minutes, setting at 9:19, and it will rise tomorrow at 6:18. The Moon, 2 days before new, will rise at 5:28 tomorrow morning.
Tomorrow, Saturday, the 22nd, there, will be viewing of the summer starry skies at the Northwestern Michigan College’s Rogers Observatory starting at 9 p.m. While starting before sunset, if it’s clear Jupiter should be spotted before 10 p.m. The planet Saturn and its rings will also be featured. By 10:30 the sky should be dark enough to spot some of the wonders among the stars, like star clusters, and nebulae that are the either the birth places of stars or the expelled remnants of dying stars. The Milky Way takes over the dark sky, it is its wonders that we see. The Observatory is located south of Traverse City on Birmley road. Take Garfield Road two traffic lights south of South Airport Road to turn right at Birmley Road.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
07/17/2017 – Ephemeris – Constellations of the Summer Triangle III: Aquila the Eagle
Ephemeris for Monday, July 17th. Today the Sun will be up for 15 hours and 9 minutes, setting at 9:23, and it will rise tomorrow at 6:14. The Moon, 1 day past last quarter, will rise at 2:08 tomorrow morning.
Aquila the eagle is a constellation that lies in the Milky Way. It’s in the southeastern sky as it gets dark. Its brightest star, Altair is one of the stars of the Summer Triangle, the group of three bright stars dominating the eastern sky in the evening now. Altair, in the head of the eagle, is flanked by two slightly dimmer stars, the shoulders of the eagle. The eagle is flying northeastward through the Milky Way. Its wings are seen in the wing tip stars. A curved group of stars to the lower right of Altair is its tail. Within Aquila the Milky Way shows many dark clouds as part of the Great Rift that splits it here. The other summer bird is Cygnus the swan above and left of Aquila, flying in the opposite direction.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Summer Triangle. Created using Stellarium and The Gimp.
Animated Cygnus finder chart. Created using Stellarium.
Bob Moler's Ephemeris Blog 