Archive
The March edition of Bob Moler’s Ephemeris is up
02/28/11 – Ephemeris – Preview of March skies
Monday, February 28th. The sun will rise at 7:22. It’ll be up for 11 hours and 6 minutes, setting at 6:28. The moon, half way from last quarter to new, will rise at 5:34 tomorrow morning.
During March, which starts tomorrow, the increase in daylight hours are at its greatest, with Spring 3 weeks away. Daylight hours will increase from 11 hours and 9 minutes tomorrow to 12 hours and 42 minutes on the 31st. Along with that the altitude of the sun at noon will increase from 38 degrees tomorrow to 49 ½ degrees at month’s end. Local noon, by the way for Interlochen and Traverse City is about 12:50 p.m, which is mainly due to the fact that our standard time meridian happens to run through Philadelphia. The MESSENGER spacecraft will arrive at Mercury and will enter into orbit of this innermost planet after a 7 year odyssey on the 18th. Here on earth spring will start at 7 20 p.m. on the 20th.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
02/25/11 – Ephemeris – The constellation of the Unicorn
Friday, February 25th. The sun will rise at 7:27. It’ll be up for 10 hours and 57 minutes, setting at 6:24. The moon, 1 day past last quarter, will rise at 3:37 tomorrow morning.
Among all the constellations in the sky of animals real and mythical, there is also a unicorn. It’s called Monoceros, and inhabits the southeastern sky at 9 p.m. bounded by Orion on the right, Canis Major, the great dog below and Canis Minor, the little dog to the left. Unfortunately for observers without optical aid Monoceros, though large, is devoid of any but the faintest stars. Maybe that’s why no one sees unicorns anymore. It has many faint stars because the Milky Way runs through it. To the telescope it is a feast of faint nebulae or clouds of gas and dust, the birth place of stars, including the red rose of the Rosette Nebula, and the strange and tiny Hubble’s Variable Nebula. It contains no bright stars, but a wealth of wonders below the surface so to speak.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
02/24/11 – Ephemeris – The sextuple star Castor
Thursday, February 24th. The sun will rise at 7:28. It’ll be up for 10 hours and 54 minutes, setting at 6:23. The moon, at last quarter today, will rise at 2:41 tomorrow morning.
High in the southeast at 9 p.m. is the constellation of Gemini the twins. The heads of the two lads contain bright stars with their names. Brighter Pollux is below and Castor is above. Stars that delineate their bodies lie to the lower right of them stretching out in the direction of Orion. Castor is an interesting star because it is actually six stars. Two are easily seen. The two brightest component stars can be resolved in a small telescope with good optics and a steady atmosphere. Each has a red dwarf companion detectable only by indirect means. The fifth and sixth stars makes a faint eclipsing binary or red dwarf stars some distance away and very faint. The Castor system resides some 50 light years away.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
02/23/11 – Ephemeris – The bright planets this week
Wednesday, February 23rd. The sun will rise at 7:30. It’ll be up for 10 hours and 51 minutes, setting at 6:21. The moon, 1 day before last quarter, will rise at 1:36 tomorrow morning.
Time again to take a look at the whereabouts of the bright planets for this week. The planet Jupiter is up in the west southwestern sky in the early evening. It is a spectacular sight in a telescope with its four satellites, shifting their positions from night to night, and the cloud bands running in the directions of the satellites. Jupiter is the brightest star-like object in the evening before it sets at 9:04 p.m. The ringed planet Saturn will rise at 9:46 p.m. in the east southeast and will move due south at 3:32 a.m. Venus is brilliant in the morning sky and will rise at 5:28 a.m. in the east southeast. It is really a beautiful sight in the morning twilight. Mercury is now too close to the direction of the sun to be seen, as is Mars which is now in the morning sky.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
02/22/11 – Ephemeris – The star Sirius and the star cluster M41
Tuesday, February 22nd. The sun will rise at 7:32. It’ll be up for 10 hours and 48 minutes, setting at 6:20. The moon, 2 days before last quarter, will rise at 12:24 tomorrow morning.
The brightest night time star Sirius is just about due south at 9 p.m. Otherwise Sirius can be found by following the three bright stars of Orion’s belt higher in the south southwest down to Sirius. In binoculars Sirius is a dazzling blue-white diamond. While officially pure white, Sirius has an arc light blue tinge. After checking out Sirius in binoculars shift your view one binocular field down and you will come to a beautiful field of faint stars. This is M41, number 41 on comet hunter Charles Messier’s list of fuzzy objects that weren’t comets. Binoculars may see up to 25 stars, telescopes even more. You might even be able to spot it with the unaided eye. It’s a whopping 2,300 light years away.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
02/21/11 – Ephemeris – The constellation Orion in mythology
President’s Day, Monday, February 21st. The sun will rise at 7:33. It’ll be up for 10 hours and 45 minutes, setting at 6:19. The moon, half way from full to last quarter, will rise at 11:08 this evening.
The large and bright constellation of Orion is now in the southeast at 9 p.m. It is seen as an upright rectangle of bright stars, with a belt of three stars in the center. Orion is a minor character in Greek mythology. Orion was the son of Neptune, and was a hunter. He had an ill fated romance with Merope, whose father King Oenopion, had him blinded. After having his sight restored, Orion became a companion of Diana goddess of the hunt and they wanted to marry. Apollo, Diana’s brother disapproved of Orion also and was able to trick Diana into accidentally killing Orion with her bow. The heartbroken Diana then placed Orion in the sky with his hunting dogs, were we see him to this day.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
02/18/11 – Ephemeris – Jupiter is getting its belt back
Friday, February 18th. The sun will rise at 7:38. It’ll be up for 10 hours and 36 minutes, setting at 6:14. The moon, at full today, will rise at 7:10 this evening.
Ever since Jupiter appeared in the morning sky, after passing behind the sun, 9 months ago it had lost its dark southern equatorial belt. Now there are visual and infrared signs that the belt is coming back. Belts are lower clouds than the bright clouds. They appear bright in the infrared. While Jupiter’s cloud tops are 200 degrees below zero, the interior of Jupiter is incredibly hot. In fact it radiates twice as much heat as it gets from the sun. Where the southern equatorial belt should be there is a crack appearing in the high cloud deck where the interior heat is showing up. We are getting to the point where Jupiter is going to pass behind the sun and out of view. April 6th is that date. I wonder if we are going to be able to see the complete restoration of the belt.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
02/17/11 – Ephemeris – The whole sun is visible now
Thursday, February 17th. The sun will rise at 7:39. It’ll be up for 10 hours and 33 minutes, setting at 6:13. The moon, 1 day before full, will set at 7:24 tomorrow morning.
Four and a half years ago NASA launched a two spacecraft on a single rocket. One was sent ahead of the earth, and the other to trail behind the earth in its orbit. They are called Stereo, and give us a stereo view of the sun. Earlier this month they reached points 90 degrees ahead and behind the earth. They now cover the complete sun, front and back. For the next 9 years we should get coverage of the far side of the sun, so we’ll see what’s brewing in the way of sunspots and other solar phenomena before they rotate around to the side that faces the earth. The sun rotates slowly, and as a fluid body. At the equator the sun rotates in 25 days, at the poles it drops to 36 days. This differential rotation causes the sun’s magnetic field to tangle and break.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
02/16/11 – Ephemeris – The bright planets this week
Wednesday, February 16th. The sun will rise at 7:41. It’ll be up for 10 hours and 30 minutes, setting at 6:12. The moon, 2 days before full, will set at 6:54 tomorrow morning.
Time again to take a look at the whereabouts of the bright planets for this week. The planet Jupiter is up in the west southwestern sky in the early evening. It is a spectacular sight in a telescope with its four satellites, shifting their positions from night to night, and the cloud bands running in the directions of the satellites. Jupiter is the brightest star-like object in the evening before it sets. It’s located left the Circlet in Pisces now and will set at 9:23 p.m. The ringed planet Saturn will rise at 10:16 p.m. in the east southeast and will move due south at 4:01 a.m. Venus is brilliant in the morning sky and will rise at 5:24 a.m. in the east southeast. Mercury is now too close to the direction of the sun to be seen, as is Mars which is now in the morning sky.
* Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Bob Moler's Ephemeris Blog 