“Meteor-ocre” Prospects for Perseids & What’s Up in Cygnus
August 2014 :
My August column is usually one of the easiest articles to pen because I can highlight the annual and often productive meteor shower of the year—the Perseids. Who doesn’t love to sit outside on a warm summer evening to watch “burning rocks” blaze across the sky? Though the meteors are really not burning, these particles shed by Comet 109P/Swift-Tuttle do completely disintegrate as they plunge into our atmosphere at around 134,222 miles per hour (or approximately 37 miles per second). Unfortunately the prospects are not ideal for this year’s display.
The Perseids peak on the night of August 12–13. While an observer located well away from light-polluted skies can usually expect to see 60+ meteors per hour at peak, a bright waning gibbous Moon (Full on the 10th) will be in the sky the entire night. This circumstance will severely reduce the number of meteors that can be observed. It is fortunate that some members of the Perseids are bright and often explode as fireballs. Perhaps only 20 or so green, red or orange meteors per hour will be seen. Should hazy summer skies prevail, the visibility of the Perseids will be further reduced. The peak is forecast to be around 8:00 p.m. EDT, so one could begin observing as soon as evening twilight ends. However, the better time would be after midnight when the Earth plows into the particles nearly head-on.
While the area of the sky where the meteors appear to radiate from is in the constellation of Perseus, one can scan for shooting stars across the entire sky. Early in the evening after twilight Perseus will be just barely above the north-northeast horizon. By midnight the constellation will be well up in the northeast sky. (See accompanying finder chart.) If one can locate the constellation of Cassiopeia, which looks like an “M” or “W” tipped sideways, then it’s close enough. Face in this general direction when first beginning the observing session and gradually follow the radiant across the sky. The number of meteors should increase as the morning progresses.
The weather is always a concern during astronomical events, especially those that occur only on a specific day. Despite the interfering moonlight I hope it is clear for the Perseids. But if history is any lesson, I’d like to provide an additional topic worth exploring during the entire month of August and beyond. We’re bound to get a few clear nights!
One of my favorite constellations is Cygnus the Swan (also known as the Northern Cross), and during mid-August at 11:00 p.m. EDT you can find this rich star region at zenith (directly overhead). Review the accompanying star chart to help identify a few stars comprising this star pattern, as well as to locate two star clusters.
In a dark sky even one’s naked-eye will reveal just how star-rich this region of the heavens is. Here one can observe the gossamer cloud of tenuous light called the Milky Way that begins in Perseus to the north and stretches through Cygnus to the heart of our galaxy in Sagittarius to the south. In the middle of Cygnus, the Milky Way divides into two separate streams of stars. Scan with a pair of 7 X 50 binoculars for an amazing view. Just north of Deneb is a large open cluster of stars. It’s called M39, the 39th catalogue entry of a famous astronomer Charles Messier (1730–1817), and contains about 20 bright stars.
Just south from Sadr is another open cluster called M29. This one only contains about eight bright stars, but the cluster is more compact than M39. The four brightest stars of this group form a square.
Both of these clusters can be found using binoculars, but a telescope of any aperture with a low-power eyepiece will enhance the view.
In addition, for telescope users there’s one of the finest double stars in the sky in Cygnus. It’s named Albireo and it represents the beak of the Swan (or the bottom end of the Northern Cross). When double star observing was somewhat new, every observer tried to outdo one another when describing the colors of the double stars they were observing. For instance, the components of Albireo were described as sapphire blue and topaz yellow. Well, I call them the “Cub Scout” stars—blue and gold. The scouts who visit us at Seagrave Observatory certainly like that description!
And finally, stars in a region straddling the Cygnus-Lyra border were the target of the Kepler Mission’s search for habitable exoplanets (extra-solar planets). Launched on March 7, 2009, the Kepler telescope found more than 3,845 candidate worlds. To date 966 have been confirmed. And this search covered a very tiny fraction of the sky. When I was growing up we only knew about the nine planets of our solar system. In grade school and high school during the 60’s and early 70’s, planetary formation was thought to be an exception. No longer.
Even before the Kepler Mission, many planets were found around other stars. Detecting these planets is a great achievement in itself. But the burning question we all want answered is, can any of these planets support life? If they orbit their star in the habitable zone where liquid water can exist, then life could be a possibility. A vast majority of Kepler’s discoveries are larger than the Earth. However, on April 17 of this year, it was announced that an Earth-sized world was discovered within the habitable zone of a red dwarf star about 500 light years away. This planet, one of five known in the system, was named Kepler 186-f.
While we may never know if Kepler 186-f supports life, discovery serves to stimulate conversation on whether the Earth is the only planet capable of supporting life in this vast universe. The Kepler Mission has succeeded in exponentially increasing the possibilities for extraterrestrial life. The challenge going forward will be to detect it.
Visit the local observatories to marvel at the wonders of the universe than can be observed from this pile of rock called Earth orbiting in the habitable zone of our star, Sol. Seagrave Memorial Observatory in North Scituate is open every clear Saturday night. Ladd Observatory in Providence is open every clear Tuesday night. Frosty Drew Observatory in Charlestown’s Ninigret Park is open every clear Friday night. Be sure to check all the websites for the schedules and opening times before visiting these facilities.
