Archive

Author Archive

08/23/2019 – Ephemeris – Two small constellations around the Summer Triangle

August 23, 2019 Leave a comment

Ephemeris for Friday, August 23rd. Today the Sun will be up for 13 hours and 41 minutes, setting at 8:35, and it will rise tomorrow at 6:55. The Moon, at last quarter today, will rise at 12:43 tomorrow morning.

Located below the eastern edge of the Summer Triangle of three of the brightest stars in the sky, which is overhead in our sky at 10 p.m., is the tiny constellation of Delphinus the dolphin. Delphinus’ 6 stars in a small parallelogram with a tail, really does look like a dolphin leaping out of the water. The parallelogram itself has the name Job’s Coffin. The origin of this asterism or informal constellation is unknown. Of the dolphin itself: the ancient Greeks appreciated this aquatic mammal as we do, and told stories of dolphins rescuing shipwrecked sailors. There’s another tiny constellation to the right of Delphinus, Sagitta the arrow a small thin group of 5 stars, which represents Cupid’s dart. Above-right of Sagitta binoculars will find a little star group called the Coat hanger.

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

Addendum

Delphinus and Sagitta finder animation

Delphinus and Sagitta finder animation. Created using Stellarium and GIMP.

Closeup of Sagitta and the binocular asterism the Coathanger. Created using Stellarium.

08/22/2019 – Ephemeris – Scanning the Milky Way in and around Sagittarius

August 22, 2019 Leave a comment

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.

08/21/2019 – Ephemeris – Where are all the bright planets?

August 21, 2019 1 comment

Ephemeris for Wednesday, August 21st. Today the Sun will be up for 13 hours and 47 minutes, setting at 8:39, and it will rise tomorrow at 6:53. The Moon, 2 days before last quarter, will rise at 11:41 this evening.

Let’s look at the planets for this week. Mars and Venus are too close to the Sun to be seen. Mars is still on the evening or east side of the Sun, as is Venus which passed superior conjunction with the Sun a week ago. Bright Jupiter will be in the southern sky as it gets dark. With steadily held binoculars a few of the 4 largest satellites of Jupiter can be seen. Four of Jupiter’s largest satellites can be spotted in telescopes tonight. Jupiter will set at 1:04 a.m. Saturn, the ringed planet, will be in the southern sky in the evening. It will pass the meridian, due south at 10:45 p.m. and will set at 3:12 a.m. Mercury will rise at 5:44 a.m. in the east-northeast.

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

Addendum

Evening planets

Jupiter, Saturn and the Moon with the bright stars of the southern summer sky at 10 p.m. August 21, 2019. Click on the image to enlarge. Created using Stellarium.

Telescopic Planets

Telescopic views of Jupiter and Saturn with the same magnification at 10 p.m.August 21, 2019. Created using Cartes du Ciel (Sky Charts).

Moon, Mercury and bright stars in the morning twilight

The Moon, Mercury and bright stars in the morning twilight at 6 a.m. August 22, 2019. Created using Stellarium.

Binocular Moon

The waning gibbous Moon at 6 a.m. August 22, 2019. Created using Stellarium.

Planets and the Moon on a single night

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on August 21, 2019. The night ends on the left with sunrise on the 22nd. Click on the image to enlarge. Created using my LookingUp program.

08/20/2019 – Ephemeris – To find Sagittarius, look for the Teapot

August 20, 2019 Leave a comment

Ephemeris for Tuesday, August 20th. Today the Sun will be up for 13 hours and 49 minutes, setting at 8:40, and it will rise tomorrow at 6:51. The Moon, 3 days before last quarter, will rise at 11:16 this evening.

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. Saturn this year is above and left of it.

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

Addendum

Sagittarius Teapot finder animation based of August 20, 2019 at 10:30 p.m. It includes the tiny asterism Terebellum, Latin for auger. It’s made to faint 4th and 5th magnitude stars. Created using Stellarium and GIMP.

08/19/2019 – Ephemeris – The dimmest looking star of the Summer Triangle is by far the brightest

August 19, 2019 Leave a comment

Ephemeris for Monday, August 19th. Today the Sun will be up for 13 hours and 52 minutes, setting at 8:42, and it will rise tomorrow at 6:50. The Moon, half way from full to last quarter, will rise at 10:53 this evening.

This evening when it gets dark the bright star Deneb in Cygnus the swan will be very high in the east. Deneb is the dimmest star of the summer triangle. Of the other stars of the triangle, Vega is higher nearly overhead, while Altair is lower in the southeast. While Deneb’s apparent magnitude, or brightness as seen from Earth, makes it the dimmest of the three bright stars, Deneb’s vast distance of possibly 2,600 light years* makes it over 90 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 196 thousand suns; and a huge star, possibly as large in diameter as the orbit of the Earth. For all this it is only 20 to 25 times the mass of the Sun.

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

Addendum

Great Rift in the Summer Triangle

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 last year in a vain attempt to capture some meteors.

08/16/2019 – Ephemeris – The Apollo missions provided clues as to the origin of the Moon

August 16, 2019 Comments off

Ephemeris for Friday, August 16th. Today the Sun will be up for 14 hours and 1 minute, setting at 8:47, and it will rise tomorrow at 6:47. The Moon, 1 day past full, will rise at 9:44 this evening.

Members of the Grand Traverse Astronomical Society will be in Downtown Traverse City for Friday Night Line again this evening. We might get a glimpse of the Moon later tonight. Speaking of the Moon, the rocks brought back from the Moon by the Apollo astronauts turn out to be very similar to earthly rocks. This gave rise to the most popular theory of how the Moon formed. A second planet was born in the Earth’s orbit lazily orbiting at a point 60 degrees ahead or behind the Earth itself. Perturbations possibly by Venus caused it to crash into the Earth with a glancing blow sending debris into orbit of the Earth to become the Moon. It explains the similarity of the rocks of the Earth and and those brought back from the Moon.

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

Addendum

How the Moon may have formed

A progression of how the Moon may have fomed by a small protoplanet crashing into the Earth. Credit: Brian Koberlein

 

Categories: Uncategorized

08/15/2019 – Ephemeris – Looking back at Apollo 12

August 15, 2019 Comments off

Sorry for the late post.  I had a short hospital stay due to something that happened to me early Wednesday.

Ephemeris for Thursday, 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, at full today, will rise at 9:17 this evening.

Apollo 11 wasn’t the only moon landing mission in 1969. Four months after Apollo 11 took off Apollo 12 lifted off into ominous skies on November 14th. The rocket was struck by lightning shortly after takeoff, and popped the circuit breakers in the command module, but didn’t affect the computers controlling the Saturn V. The astronauts were able to reset everything in time for TLI, Trans Lunar Injection. They landed as intended some 600 feet from the Surveyor 3 lander spacecraft sent to the Moon 2 and a half years earlier. They cut off the spacecraft camera to return to the Earth. The improved color TV camera they brought with them was damaged when it was inadvertently pointed to the Sun while setting it up.

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

Addendum

The crew of Apollo 12 left to right: Pete Conrad, Richard Gordon, and Alan Bean. Credit: NASA.

Pete Conrad visiting Surveyor 3. Credit NASA/Alan Bean.