Archive
11/21/2016 – Ephemeris – The two fishies of Pisces
Ephemeris for Monday, November 21st. The Sun will rise at 7:48. It’ll be up for 9 hours and 20 minutes, setting at 5:08. The Moon, at last quarter today, will rise at 12:54 tomorrow morning.
High in the south-southeast at 9 p.m. are the four bright stars of the Great Square of Pegasus, the upside down flying horse. Lying along the left and bottom sides of the great square is the constellation of Pisces the fish, one of the 12 constellations of the Zodiac that lie along the path of the sun, moon and planets. Even though the constellation is called the fish, the fish themselves are not represented in the stars. What can be traced in the stars is the rope, that’s tied to their tails, anchored at the extreme southeastern part of the constellation that is seen in the stars. The right or western end of Pisces is the asterism, or informal constellation, of the Circlet. It’s the loop of 5 stars, the rope around the tail of one of the two fish.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
An animation of the constellation of Pisces the fish, showing first the stars, then the constellation outline including those of Pegasus, and Aquarius, then an artist rendering. Created using Stellarium and GIMP.
I don’t care what the artists think, I still think the circlet is a loop around the western fish’s tail.
11/18/2016 – Ephemeris – Aquarius the water spiller
Ephemeris for Friday, November 18th. The Sun will rise at 7:44. It’ll be up for 9 hours and 26 minutes, setting at 5:11. The Moon, 3 days before last quarter, will rise at 9:43 this evening.
One of the constellations of the zodiac is in the south-southwestern sky at 8 in the evening. It’s the constellation of Aquarius the water bearer. The image that is supposed to be depicted in the stars is that of a hapless fellow spilling a stone jar of water across the sky. Aquarius is fairly hard to spot because it is made of faint stars. One part of him, though, is easy to spot. That is the Water Jar, an asterism or informal constellation. It is a distinctive small nearly equilateral triangle of stars with another star in the center. Stars extending to the right from the water jar are he yoke he’s holding the water jar with. The Water jar is just below the top of the head of the upside down Pegasus the flying horse. The water is flowing down a vertical line of stars.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Aquarius the water bearer or rather spiller at 8 p.m. tonight, November 18. Note that Mars is in the next constellation west, Capricornus, and will enter Aquarius about mid-December. Created using Stellarium and GIMP. If you’re using the Firefox browser you can right-click on the image and display the enlarged version.
The triangle of stars with another star in the center is an asterism called the Water Jar, right where the artist drew it.
11/17/2016 – Ephemeris – The Leonid meteor shower will be hampered by the Moon tomorrow morning
Ephemeris for Thursday, November 17th. The Sun will rise at 7:43. It’ll be up for 9 hours and 29 minutes, setting at 5:12. The Moon, 3 days past full, will rise at 8:39 this evening.
The Leonid meteor shower, which reaches peak activity today is going to be washed out by the bright Moon. The International Meteor Organization doesn’t have anything specific on it this year. On most years, it produces only 15 meteors an hour tops. However about every 33 years or so all heaven breaks loose. From the predictions I’ve seen the fun starts in 2034 and lasts a few years. The reason for the spectacular meteor storms, as they call them, is that the responsible comet, 55P Tempel-Tuttle, has a debris clump that hasn’t fanned out much along its orbit, so we get intense meteor activity when the comet again enters the inner solar system. It’s expected back in 2031 with its main cloud of meteoroids a couple of years later.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Leonid meteor radiant at about 2 a.m. from Traverse City. Credit: My LookingUp program.
A famous woodcut of the 1833 Leonid meteor storm.
11/16/2016 – Ephemeris – Where are the bright planets now?
Ephemeris for Wednesday, November 16th. The Sun will rise at 7:41. It’ll be up for 9 hours and 31 minutes, setting at 5:13. The Moon, 2 days past full, will rise at 7:38 this evening.
Low in the east-southeast before 7:15 a.m. Jupiter can be glimpsed in the morning twilight. Jupiter will rise tomorrow at 4:05 a.m. We are approaching Jupiter, though it’s 5 times Earth’s distance from the Sun and will pass it April 7th. Venus, Saturn and Mars are in the evening sky. At 6 p.m. these planets will be seen in the southwest and low in the sky. Venus will be the brightest, Saturn might be picked out of the twilight to the right and below Venus, and Mars will be higher to the left. Saturn will set first at 6:30, with Venus setting at 7:33. Mars will hang on a bit longer and will set at 10:07. Mars’ setting time hasn’t changed from last week. Venus is slowly heading northward for the rest of it’s evening appearance.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The evening planets in twilight in the southwestern sky at 6 p.m. Created using Stellarium.
Jupiter rising in the morning sky this morning at 7 a.m. November 19, 2016. Created using Stellarium.
Jupiter and its Galilean moons, as they might be seen in a telescope at 7 a.m., this morning, November 16, 2016. Created using Cartes du Ciel (Sky Charts).
The Moon is visible both in the evening and the next morning. At right is the evening Moon at 8 p.m. On the left is the Moon at 7 a.m. A sharp-eyed person, with binoculars, can notice a slight change in the sunset terminator in the 11 hours between the two views. Created using Stellarium.
Planets and Moon at sunset and sunrise of a single night starting with sunset on the right on November 16, 2016. The night ends on the left with sunrise on November 17. If you are using Firefox right-click on the image and select View Image to enlarge the image. That goes for all the large images. Created using my LookingUp program.
11/15/2016 – Ephemeris – Imaging exoplanets from the ground
Ephemeris for Tuesday, November 15th. The Sun will rise at 7:40. It’ll be up for 9 hours and 33 minutes, setting at 5:14. The Moon, 1 day past full, will rise at 6:43 this evening.
There’s something I never thought I’d see in my lifetime was a telescope on the ground that could image planets around other stars. Remember that planets shine by reflecting the light of their host stars, and due to their distance of many trillion of miles away, that there would be no hope of separating the planet from the star which is billions of times brighter. My lifetime includes the launch of Sputnik, the first artificial satellite when I was in the 11th grade. However with huge telescopes with adaptive optics that take the wiggle out of the atmosphere. Added to that is the CHARIS instrument on the 8.2 meter Subaru telescope on Mauna Kea in Hawai’i, which not only can see exoplanets around stars, but take their spectra, to analyze chemical compounds in their atmospheres.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
A plot of data from CHARIS shows planets located around a star in the planetary system HR8799. (Images courtesy of N. Jeremy Kasdin and the research team)
The story is here:
http://www.princeton.edu/main/news/archive/S47/82/89C62/?section=topstories
11/14/2016 – Ephemeris – Watch the setting of the super moon this morning
Ephemeris for Monday, November 14th. The Sun will rise at 7:39. It’ll be up for 9 hours and 36 minutes, setting at 5:15. The Moon, at full today, will set this morning at 7:23 and will rise again at 5:53 this evening.
During the 6 to 7 o’clock hour this morning the Moon will be officially the closest super moon, most likely of your lifetime unless your 68 or older. Super moon’s apparently only count when the Moon is closest to the Earth at full moon. The Moon passes perigee, its closest point to the Earth once a month, but not always at full moon. It happens that both October and December’s full moons are also super moons. Rising and setting moon’s work the same way, to make the Moon appear even larger than it is. This is an optical illusion, but go with it. The Moon will be slightly farther away when it rises this evening. Moon set will occur at 7:23 or thereabouts this morning while moon rise will be at 5:53 this evening, somewhat earlier east of Traverse City, later west. Get out early if it’s clear.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The nearly full super moon at 8 p..m. EST (1 hr UT) last night. The fact that the moon is not quite full is the dullness on the Moon’s left side and a hint of a crater shadow. The Moon will be as full as it gets at 8:52 a.m. EST (13:52 UT). Credit Bob Moler
For more facts on the super moon check out these links:
http://scienceblogs.com/startswithabang/2016/11/11/supermoon-fact-vs-fiction-synopsis/
11/11/2016 – Ephemeris – Two Taurid meteor showers active now
Ephemeris for Veteran’s Day, Friday, November 11th. The Sun will rise at 7:35. It’ll be up for 9 hours and 43 minutes, setting at 5:18. The Moon, 3 days before full, will set at 4:49 tomorrow morning.
We are situated between two supposed peaks of two meteor showers, the South Taurids and the Northern Taurids. Their radiant points are roughly north and south of the face of Taurus the bull, which looks like the letter V of stars lying on its side. Both meteoroid streams belong to Encke’s Comet, the comet with the shortest known period of 3.3 years. The far end of the streams end up near Jupiter’s orbit, which allow the giant planet to split and broaden the meteoroid streams. Another feature of these streams is that they seem to be made of small pebbles rather than grains. When these pebbles hit our atmosphere at 17 miles (28 km) per second they will appear very bright. Really bright meteors are called Fireballs.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Fireball orbits traced back from November 9, 2016. The orbits marked in yellow sticking out o the right toward Jupiter’s orbit are the Taurids. Credit NASA All-sky Fireball Network via spaceweather.com.
NASA has three widely spaced sets of all-sky cameras which allow it to get 3-D views of fireballs entering the Earth’s atmosphere. which allow the measurement of velocity of the object and the determination of the meteoroid’s orbit before it hit Earth’s atmosphere. For more information go to: http://fireballs.ndc.nasa.gov/
11/10/16 – Ephemeris – Sunrise on Aristarchus
Ephemeris for Thursday, November 10th. The Sun will rise at 7:33. It’ll be up for 9 hours and 45 minutes, setting at 5:19. The Moon, 3 days past first quarter, will set at 3:35 tomorrow morning.
Tuesday I discussed the fact that the Moon appears to rock back and forth over the month due to it’s uneven motion around the Earth. Currently it’s still facing the direction of the Sun by nearly as far as it was on Tuesday, which is revealing a crater on the northeastern side of the Moon about a day earlier than average in the lunar monthly cycle. That crater is the brightest spot on the Moon, though it’s not that bright right now because that crater, called Aristarchus, is filled with shadow. That shadow will go away in a day or two. Aristarchus is visible in binoculars at the terminator, the advancing sunrise line on the Moon. Aristarchus is located on the flat lava plains that early telescopic astronomers thought were seas filled with water.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The moon with the Crater Aristarchus on the sunrise terminator at 9 p.m. November 10, 2016. Created using Virtual Moon Atlas.
11/09/2016 – Ephemeris – Your mid-week bright planet report
Ephemeris for Wednesday, November 9th. The Sun will rise at 7:32. It’ll be up for 9 hours and 48 minutes, setting at 5:20. The Moon, 2 days past first quarter, will set at 2:23 tomorrow morning.
Low in the east-southeast at 6 a.m. Jupiter can be glimpsed in the morning twilight. Jupiter will rise tomorrow at 4:25 a.m. We are approaching Jupiter, though it’s 5 times Earth’s distance from the Sun and will pass it April 7th. Venus, Saturn and Mars are in the evening sky. At 6 p.m. these planets will be seen in the southwest and low in the sky. Venus will be the brightest, Saturn might be picked out of the twilight to the right and a bit below Venus, and Mars will be higher to the left. Saturn will set first at 6:54, with Venus setting a half and hour later at 7:24. Mars will hang on a bit longer and will set at 10:07. Venus is almost at its farthest south in the sky, and will be slowly heading northward for the rest of it’s evening appearance.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The evening planets in twilight in the southwestern sky at 6 p.m. November 9, 2016. Created using Stellarium.
Looking south at Mars, two bright stars, and the Moon at 8 p.m. November 9, 2016. Created using Stellarium.
The Moon as it might be seen in binoculars at 8 p.m. November 9, 2016. Created using Stellarium.
Jupiter in the morning sky at 6:30 a.m. November 10, 2016. Created using Stellarium.
Jupiter and its Galilean moons, as they might be seen in a telescope at 6 a.m. November 11, 2016. Created using Cartes du Ciel (Sky Charts). Note the image is not inverted.
Planets and Moon at sunset and sunrise of a single night starting with sunset on the right on November 9, 2016. The night ends on the left with sunrise on November 10. If you are using Firefox right-click on the image and select View Image to enlarge the image. That goes for all the large images. Created using my LookingUp program.
11/08/2016 – Ephemeris – As the Moon wobbles
Ephemeris for Election Day, Tuesday, November 8th. The Sun will rise at 7:31. It’ll be up for 9 hours and 50 minutes, setting at 5:21. The Moon, 1 day past first quarter, will set at 1:14 tomorrow morning.
Tonight’s Moon bears close examination. The Moon has an elliptical orbit of the Earth, so its motion around the Earth moves fastest when nearer and slower when farther from the Earth. The Moon’s rotational speed, however is constant, Because of this the Moon appears to wobble back and forth. It also nods a bit. The effect is called libration. As of yesterday the Moon was rotated its greatest to the right for the month. It’s a small amount, only 8 degrees. On the 18th only 10 days from now the moon will nod 8 degrees to the left. A good way to tell the state of this libration for the waxing Moon is to check the position of the small gray sea near the right edge of the Moon, the Sea of Crises. Now it’s right at the edge of the Moon.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Simulation of the Moon’s phase and libration for October 2007 by Tomruen. Image is in the Public Domain. Downloaded from the Wikipedia entry for the Moon.
You can run a continuous simulation like this using the free program Virtual Moon Atlas.
