Skywatch Line for Friday, September 18th through Sunday, September 20th

This is Dudley Observatory’s Skywatch Line for Friday, September 18, through Sunday, September 20, written by Alan French.

The Moon will reach first quarter very early Monday morning, so a waxing crescent will dominate the early evening skies this weekend. The Moon sets at 9:57 pm Friday, 10:38 pm Saturday, and 11:25 pm on Sunday.

Weather permitting; the Albany Area Amateur Astronomers, in association with NYS Parks, will hold a public star party at 7:30 pm on Friday, September 18, at the Deerfield Pavilion in Grafton Lakes State Park. At star parties telescopes are set up to provide guests with views of a variety of celestial objects – galaxies, nebular, star clusters, and double stars. Lovely ringed Saturn will be visible low in the southwest during the early part of the star party.

All ages are welcome and there is no admission charge. For directions visit this web site, call the Park office 279-1155, or use the address 100 Grafton Lakes State Park Way, Grafton, NY, 12082.

The star party will be canceled if the skies are mostly cloudy. If weather permits, it will be rescheduled for 7:30 pm on Saturday, September 19. In case of possible cancellation, or for more information, call one of the coordinators, Ray (658-3138) or Bernard (658-9144).

If you look fairly high in the southern sky around 9:00 pm you should spot the bright yellow-white star, Altair. If you’re looking at the right star, it has two fainter stars to either side, one roughly to the lower left and one at about equal distance away on the other side. Altair is the brightest star in Aquila, the Eagle, and its name means “the flying eagle.”

Like most of the brightest stars, Altair shines brightly because it is one of our nearer neighbors, lying at a distance of just under 17 light years. The light you see tonight, traveling 186,000 miles every second, left the star in 1998, the year many watched “Armageddon” and “Deep Impact.” The 1956 science fiction classic, “Forbidden Planet,” was about a visit to Altair 5, a planet orbiting Altair.

The star to the lower left of Altair, Alshain, lies almost 48 light years away, while the one to the upper right, Tarazed, is 390 light years from us. As you can imagine, Tarazed is inherently much brighter than Alshain, but its light is dimmed by its greater distance.

Don’t forget to check next weekend’s Skywatch Line for details on the total lunar eclipse on Sunday night, September 27.

Skywatch Line for Wednesday, September 16th and Thursday, September 17th

This is the Dudley Observatory Skywatch Line for Wednesday, September 16th and Thursday, September 17th written by Louis Suarato

The 12% illuminated, waxing crescent Moon can be seen low over the west-southwestern horizon after sunset before setting at 8:30 p.m. Wednesday evening. This is a good time to see “Earthshine” on the Moon. Earthshine is sunlight reflecting from the Earth onto the Moon’s shadowed surface creating a faint glow. It was Leonardo Da Vinci who concluded that Earthshine was created by the Earth’s reflected sunlight. Da Vinci was wrong about sunlight reflecting off the Earth’s oceans onto the Moon’s oceans, since Earthshine occurs when sunlight reflects off the Earth’s clouds, and, of course, the Moon doesn’t have oceans. But given Da Vinci’s perceptions occurred during the early 1500’s, years before even Copernicus’ heliocentric theories were published, it was an amazing discovery. Earthshine, also known as “The Da VInci Glow”, is best viewed 1 to 5 days before and after the New Moon.

You can find Saturn in the constellation Libra, to the upper left of the crescent Moon. Look about 15 degrees over the southwestern horizon. It was September 17, 1789 when William Herschel discovered Saturn’s moon Mimas. Mimas is the 7th largest moon of Saturn, and the 20th largest in the solar system. Mimas’ most outstanding feature is a gigantic crater known as Herschel. This crater measures one-third of Mimas’ 242 mile diameter.

The pre-dawn hours welcome the arrival of three planets. Venus is the first to rise at 3:40 a.m. Thursday, followed by Mars at 4:08 and Jupiter at 5:15. Look over the eastern horizon for all three planets. Continue to follow these planets as they draw closer during October.

The Dudley Observatory will host two events this week. The first is a lecture and star party at the Octagonal Barn in Delanson, NY on Friday, September 18th, beginning at 7 pm. The lecture will be given by Dudley Observatory’s archivist Josh Hauck on “A Scientific Sweatshop: The Industrialization of American Science and the Women of Dudley Observatory”. The Dudley Observatory will also be hosting “International Observe the Moon Night” at MiSci in Schenectady, beginning at 7 pm on Saturday, September 19th. More information about these events can be found at

The Albany Area Amateur Astronomers will be hosting a Star Watch on Friday, September 18th at Grafton Lake State Park. If the Friday event is cancelled, it will be held Saturday night.

Night Sky Adventures @ miSci Tuesday, August 18, 8pm “Perseids Meteor Shower”

The Perseids is one of the best meteor showers to observe, producing up to 60 bright meteors per hour at its peak. It is produced by comet Swift-Tuttle, which was discovered in 1862. The shower runs annually from July 17 to August 24 and peaks on the night of August 12th and the morning of the 13th. The thin crescent moon will be no match for the bright Perseids this year so be prepared for best viewing from a dark location after midnight. Meteors will radiate from the constellation Perseus, but can appear anywhere in the sky.

miSci, 15 Nott Terrace Heights, Schenectady, New York 12308 518-382-7890

$3 per person, $5 per family, free for miSci members.

Lead by astronomy educators and volunteers from the Albany Area Amateur Astronomers group. We practice identifying stars, constellations, and dark sky objects both through telescopes (weather permitting) and indoors in the planetarium.

Amateur astronomers and families are invited to bring binoculars or telescopes. One or more telescopes will be provided by The Dudley.

Family friendly! Programs will be held rain or shine!

Dudley Observatory @ miSci
15 Nott Terrace Heights
Schenectady, NY 12308
(518) 382-7890 ext 259

Octagon Barn Lecture and Star Party, Friday, August 14th, 8 pm “The Copernican Revolution: Myth vs. Reality”

Presented by Harry Ringermacher, Ph.D.

Born just twenty-two years after the invention of Gutenberg’s printing press, Copernicus lived in a tumultuous and changing time. His work challenged the familiar order of society. This presentation will illuminate you on his life and times, his place in society, his relationship with the church. It will explain the science and his ideas that changed it. We will learn how time has remembered Copernicus, the man who on his death bed held a copy of his book and exclaimed with his last breath, “My life – the stars!”

Monthly Astronomy Talks & Dark Sky Star Viewing, Delanson, NY. Fridays in 2015

Family friendly. Programs will be held rain or shine.
Amateur astronomers and families are invited to bring binoculars or telescopes.
Free Admission – $5 donation graciously accepted

Octagon Barn, 588 Middle Road, Delanson NY 12053