Archive
08/09/2012 – Ephemeris – Viewing the Perseid meteor shower
Ephemeris for Thursday, August 9th. The sun rises at 6:38. It’ll be up for 14 hours and 17 minutes, setting at 8:56. The moon, at last quarter today, will rise at 12:24 tomorrow morning.
Lets take a look at what will happen this weekend with the Perseid meteor shower. We seem to have two meteoroid streams intercepting the earths. The earth will pass through the classic stream Saturday night, Sunday morning. The earth is expected to pass through a second stream Sunday Night, Monday morning. In the early evening the meteors are fewer, but the trails will be longer. The meteors will seem to come from the constellation of Perseus which lies below the W shaped constellation of Cassiopeia in the northeast. At two or three in the morning will see the greatest numbers of meteors, up to 60 meteors an hour. Tomorrow I’ll tell you about two events and places to go to join others in viewing the shower.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Perseid radiant at 10:30 p.m.
Perseid Meteor Shower radiant after midnight
08/07/2012 – Ephemeris – the comet responsible for the Perseid meteor shower
Ephemeris for Tuesday, August 7th. The sun rises at 6:36. It’ll be up for 14 hours and 22 minutes, setting at 8:59. The moon, 2 days before last quarter, will rise at 11:20 this evening.
The Perseid meteor shower is so named because the meteors seem to come from the direction of the constellation of Perseus which starts in the evening low in the northeast and rotates up throughout the night higher and higher. The comet responsible is Comet Swift-Tuttle, discovered in 1862 by Lewis Swift and Horace Tuttle. The comet has a 130 year orbit and returned in 1992. It’s orbit intersects ours at a 113 degree angle, which is why the radiant point is so far north. The Perseids have been recorded for 2,000 years so the comet has been around much longer than that. It’s nucleus is 17 miles in diameter, about twice that of Halley’s Comet. While Comet Swift-Tuttle won’t be back this century, we can see bits of it tonight.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
08/06/2012 – Ephemeris – The Perseid Meteor Shower this weekend
Aug 6. This is Bob Moler with Ephemeris for Monday, August 6th. The sun rises at 6:35. It’ll be up for 14 hours and 25 minutes, setting at 9:00. The moon, 3 days before last quarter, will rise at 10:52 this evening.
Saturday night through Sunday morning will be the period of the maximum number of meteors in the Perseid meteor shower. There are many meteor showers but a few very active ones. Of these the Perseids are the most famous. Meteor showers occur the same dates during the year because meteoroid streams are debris left near the orbits of comets. If a comet passes near the earth’s orbit the debris it sheds when close to the sun will end up in orbits similar to the comet and when the earth passes the spot we experience a meteor shower. Thus in late July through mid August we pass through the meteoroid stream of debris of Comet Swift-Tuttle, whose sand to pea sized particles hit the atmosphere at 40 miles per second providing us a celestial show.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
07/19/2012 – Ephemeris – The constellation Cygnus the swan
Ephemeris for Thursday, July 19th. Today the sun will be up for 15 hours and 5 minutes, setting at 9:21. The moon is new today, and won’t be visible. | Tomorrow the sun will rise at 6:16.
High in the east northeast as it gets dark flies the constellation of Cygnus the swan. This constellation is also known as the Northern Cross. The cross is seen lying on its side with the bright star Deneb at the head of the cross to the left. The rest of the cross is delineated in the stars to the right. As a swan, Deneb is the tail, the stars of the crosspiece of the cross are the leading edges of wings as Cygnus flies south through the Milky Way. There are faint stars that also define the tips and trailing edges of its wings. It is a very good portrayal of a flying swan, like the mute swans we see on the wing. In Greek mythology this was the disguise of the god Zeus who seduced the young lady Leda and fathered the immortal of the Gemini twins Pollux.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Cygnus and the stars of the Summer Triangle at 11 p.m. on July 19th. Created using Stellarium.
07/16/2012 – Ephemeris – The constellation Draco the dragon
Ephemeris for Monday, July 16th. Today the sun will be up for 15 hours and 10 minutes, setting at 9:23. The moon, 3 days before new, will rise at 4:50 tomorrow morning. Tomorrow the sun will rise at 6:13.
High in the northern sky at 11 p.m. lies a twisted constellation, that of Draco the dragon. This dragon is more like the snake-like Chinese dragon than the dinosaur like Hungarian Horntail of Harry Potter fame. At least that’s how I see it. I find it better to start at the tail of Draco, to trace him out in the stars. Draco’s tail starts between the bowl of the Big Dipper and the Little Dipper. The Dragon is seen in a line of stars that extends parallel to the handle of the Big Dipper before curving around the bowl of the Little Dipper then bends back toward the south. The head of Draco is an odd box of stars near the bright star Vega, nearly overhead. Though not made up of very bright stars, Draco has an easy shape to trace.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Draco the dragon at 11 p.m. July 16th looking high in the north. Created using Stellarium.
Click on the image to enlarge.
Solar flare might give us an aurora Friday night to Saturday morning
A huge x-ray flare occurred in the huge sunspot group (AR 1520) now on the sun. We might be affected by about 2:20 a.m. EDT Saturday the 14th, give or take 7 hours. So check the skies Friday night. Go to spaceweather.com for more information.
07/13/2012 – Ephemeris – The moon will join Venus and Jupiter Sunday morning
Ephemeris for Friday, July 13th. Today the sun will be up for 15 hours and 15 minutes, setting at 9:25. The moon, 3 days past last quarter, will rise at 2:26 tomorrow morning. Tomorrow the sun will rise at 6:11.
Sunday Morning maybe isn’t the most convenient time to get up early, but this Sunday it may be worth it. At 5 a.m. or so Jupiter will appear above Venus, as they have for the last few weeks. But Sunday morning the crescent moon will appear right between the two. For other parts of the world the moon will actually pass in front of Jupiter, an event called an occultation. This will occur before sunrise for us. But still the planet and moon group should be a beautiful sight in the twilit sky. Venus and Jupiter will soon separate, Venus to stay near the sun, while Jupiter due to the earth’s orbital motion moves away to rise earlier and earlier by somewhat less than a half hour a week. Jupiter lies in the constellation Taurus now.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Jupiter, Venus and the moon on July 15, 2012 at 5 a,m, Created using Stellarium.
07/10/2012 – Ephemeris – The constellation of Ophiuchus
Ephemeris for Tuesday, July 10th. Today the sun will be up for 15 hours and 20 minutes, setting at 9:27. The moon, at last quarter today, will rise at 12:50 tomorrow morning. Tomorrow the sun will rise at 6:08.
The red star Antares shines in the south at 11 p.m. In the area of sky above it lies a large constellation of faint stars called Ophiuchus, the serpent bearer. Ophiuchus represent the legendary physician Aesculapius. The constellation shape is like a large bell, which reminds me of the head, shoulders and arms of a fellow that’s holding the snake like a weight lifter struggling to pull up a heavy barbell. Serpens, the constellation of the serpent is in the sky in two sections. The front end lies to the right as Serpens Caput, and wends its way up towards Corona Borealis, the Northern Crown. Serpens Cauda, the tail rises to the left of Ophiuchus. It’s a rewarding sight, and not that hard to spot.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Ophiuchus and Serpens July 10, 2012 at 11 p.m.. Created using Stellarium.
07/09/2012 – Ephemeris – The constellation of Scorpius the scorpion
Ephemeris for Monday, July 9th. Today the sun will be up for 15 hours and 21 minutes, setting at 9:28. The moon, 1 day before last quarter, will rise at 12:23 tomorrow morning. Tomorrow the sun will rise at 6:07.
There’s a large constellation located low in the south at about about 11 tonight. It’s Scorpius the scorpion. Its brightest star is Antares in its heart, a red giant star, that I get calls about from time to time as being a UFO. It’s due south at 11 this evening. From Antares to the right is a star then a vertical arc of three stars that is its head. The Scorpion’s tail is a line of stars running down to the left of Antares swooping to the horizon before coming back up and ending in a pair of stars that portray his poisonous stinger. There is a beautiful star cluster seen in binoculars at that first bend in the tail that is unfortunately too low to appreciate from this far north. I was very impressed with it when spotting it from the Florida Keys.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The constellation Scorpius at 11 p.m. on July 9, 2012. Created using Stellarium.
In the Traverse City area the bottom stars just barely clear the horizon. farther north the constellation will not fully rise above the southern horizon.
The star cluster mentioned is near the star closest to the south compass point in the view above.
NGC6231 – a great binocular star cluster visible from south of Michigan. Created using Stellarium.
In this view there is a hint of ever more stars visible in a small telescope. This recreation doesn’t do it justice.
Possibility of an aurora (northern lights) late Friday night or early Saturday morning
http:www.spaceweather.com reports that a coronal mass ejection (CME) is heading toward the earth from the sun to arrive sometime about 2 a.m. EDT Saturday July 7th. So we may get to see an aurora. Active region 1515, the biggest sunspot group on the sun now is the culprit. It’s been kicking off lots of solar flares recently. The flare responsible was one of the ones that occurred yesterday, July 4th.
