By Francine Jackson
Once again, the sign of the new season is beginning to make its way higher and higher in the sky. As October begins, the Great Square, symbol of fall, is getting easier to find in the southeast.
: By Glenn ChapleAutumn is a season of promise for the stargazers. The nights are getting longer, the air clearer, and those pesky summer mosquitoes are a thing of the past. In a few months, Orion and his magnificent wintry retinue will take center stage. While the autumn night sky appears devoid of bright stars, it’s still home to a rich array of double stars. Here are ten of the best:
: By Glenn ChapleLast month, we explored the galaxy M33, a notoriously difficult telescopic target due to its extremely low surface brightness. For the same reason, M74 is even more challenging; in fact, many consider it the most visually demanding of all the Messier objects.
: By Glenn ChapleAlthough it’s a Summer Triangle constellation, Cygnus remains well-seen throughout the autumn months. Located in the star-rich fields of the Milky Way, the Swan is home to numerous double stars. Here are eight of the most noteworthy (data from the Washington Double Star Catalog.
: By Glenn ChapleA hazy summer evening may prevent you from observing nebulae and galaxies, but it could afford ideal seeing conditions for high power targets like double stars.
: By Glenn ChapleAndromeda is home to a fine collection of double stars. Here are eight of the best. Data on magnitudes and separation were taken from the Washington Double Star Catalog.
: By Glenn ChapleI’m a big fan of “off-the-beaten-path” sky objects. One of my favorites is the little-known double star Struve 817 - the 817th double star catalogued by the German-born Russian astronomer F. G. W. Struve during a survey conducted between 1824 and 1827.
: By Glenn ChapleForgive me for the apparent ego trip, but this month I’m going to introduce you to an amazing little asterism called “Chaple’s Arc.” I stumbled upon the Arc in the mid-1970s while looking for the double star h1470.
: By Glenn ChapleEpsilon Pegasi (Enif) is an optical double star comprised of magnitude 2.5 and 8.7 component stars separated by 144 seconds of arc. Pairs this wide usually don’t merit much consideration, but wait! Epsilon Pegasi has a surprise for us.
: By Craig CortisUnusual celestial objects having bizarre or extreme astrophysical properties often make highly desirable observing targets for amateur astronomers wishing to find things outside the scope of the usual, customary star party “menu”. So how do you find something that even the Hubble Space Telescope can’t image in visible light? The answer is surprisingly simple and is my topic for this month.
: By Glenn ChapleAre you ready for the eclipse of November 13th? I’m not talking about the sun or moon. I’m referring instead to an eclipse of the fascinating star ß Persei (Algol).
: By Glenn ChapleNGC 7293, the Helix Nebula, is the nearest planetary nebula (distance ~ 450 LY) and largest in apparent size (12 by 16 arcminutes). Moreover, it’s a 7th magnitude object. An easy telescopic target? Hardly! The magnitudes listed for deep-sky objects are often misleading, and the Helix Nebula is a prime example.
: By Jim HendricksonAn asterism in Cepheus that is easy to find in small telescopes or binoculars is comprised of 10 stars between magnitude 6.0 and 9.5 and very closely approximates the shape of the northern sky’s most famous asterism-the Big Dipper
: By Glenn ChapleLast month, we looked at the prototypical eclipsing binary beta Persei (Algol). This month, we turn to another prototype, the classic long-period variable (LPV) omicron Ceti.
: By Glenn ChapleMany astronomers regard the Milky Way, viewed with the unaided eye on a dark, moonless night, as the most awe-inspiring heavenly sight of all. During late summer, it arches overhead, from Cassiopeia to our north, through Cygnus above, then down to Sagittarius on the southern horizon.
: By Glenn ChapleIn the southern part of Cepheus is a pair of naked eye variable stars worthy of note. The first, delta (?), is the prototypical Cepheid variable. It ranges between magnitudes 3.5 and 4.4 in a precise 5.37 day period. The rise from minimum to maximum brightness takes about 1½ days; the fade back to minimum involves an additional four.
: By Glenn ChapleHave you seen “ET” lately? Not that cute little alien in Steven Spielberg’s 1982 movie. I’m referring to the ET-mimicking open star cluster NGC 457 in Cassiopeia. Discovered by William Herschel in 1787, NGC 457 is often overlooked because of its proximity to the Messier cluster M103.
: By Glenn ChapleIn July, we looked at M92, a fine globular cluster in Hercules that’s overlooked in favor of the easier-to-find M13. The same misfortune has befallen another globular cluster - M56 in Lyra. M56 is often bypassed by backyard astronomers who favor the planetary nebula M57, conveniently positioned midway between the stars beta (β) and gamma (γ) Lyrae.
: By Francine JacksonOnce again, the sign of the new season is beginning to make its way higher and higher in the sky. As October begins, the Great Square, symbol of fall, is getting easier to find in the southeast.
: By Glenn ChapleLast month, I suggested that our featured object, Albireo, may not be the most beautiful double star in the sky and I’d introduce a rival this month. If you guessed that Albireo’s challenger is Almach, the gamma (?) star in Andromeda, you’d be correct!
: By Glenn ChapleConsider the spiral galaxy M33 in Triangulum. Listed as a 6th magnitude object, it’s notoriously difficult to view in telescopes. M33 is elusive because its light is spread over an area four times that of the full moon.
: By Glenn ChapleIf you slowly scan the southern part of Vulpecula with binoculars or rich-field telescope, you’ll come across a remarkable asterism comprised of 10 stars arranged in the distinct form of a coathanger. Six line up to form the bar, while four others create the hook. It’s quite an eye-opening sight!
: By Glenn ChapleOctober sees the demise of the summer Milky Way and its swarm of globular clusters centered on the constellation Sagittarius. A few, notably M15 in Pegasus, lag behind to grace our autumn skies. Another of these stragglers is NGC 6934 in Delphinus. This small 9th magnitude globular was discovered by William Herschel in 1785. In early star atlases and in modern-day “Herschel 400” guides, it bears the designation H1031 - the 103rd entry in Category I (bright nebulae) of Herschel’s deep sky catalog.
: By Glenn ChapleThere’s something hypnotic about a double star – two gleaming points of light shining bravely through the surrounding darkness. A triple star is even more mesmerizing. Place a double star and triple star in the same eyepiece field, and the visual effect is stunning. This is what greets the eye when you view the triple/double star combo Struve 2816 and Struve 2819.
: By Glenn ChapleI’m a double star aficionado; my sky gazing motto is “double stars are twice the fun!” Unlike the “faint fuzzies” most backyard astronomers prefer, double stars aren’t hidden by light pollution or bright moonlight. They aren’t the exclusive property of big-scope owners. In fact, many showpiece doubles are within reach of small-aperture instruments. The common 60mm refractor with its crisp stellar images delivers exquisite views of double stars - especially twin systems.
: By Glenn ChapleWhat could be a more appropriate telescopic destination for a wintry night in January than the “Blue Snowball?” More formally known as NGC 7662, the Blue Snowball is a beautiful planetary nebula located in Andromeda. Discovered by William Herschel in 1784, it sports as the nickname implies a circular form and eye-pleasing bluish hue.
Eyes on the Sky makes it easier for anyone to find objects in the night sky and/or learn how to use astronomy equipment, and educates about smarter lighting practices. Take a look at the weekly videos to learn what YOU can find in the night sky, this week - naked eye, binocular and telescopic objects are always discussed, so anyone can look up and see planets, stars and other deep sky objects.
It’s appropriate that the constellation Gemini, the Twins, should be home to a numerous collection of double stars. Here are ten stellar – pardon the pun - examples (data from the Washington Double Star Catalog (WDS).