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05/22/2018 – Ephemeris – Seeing detail on the face of Jupiter with a small telescope

May 22, 2018 Comments off

Ephemeris for Tuesday, May 22nd. Today the Sun will be up for 15 hours and 4 minutes, setting at 9:12, and it will rise tomorrow at 6:06. The Moon, 1 day past first quarter, will set at 3:27 tomorrow morning.

Even in small telescopes Jupiter shows some detail. The larger the telescope in diameter the more detail can be seen. It also depends on what astronomers call seeing, or the steadiness of the atmosphere. The easiest detail to spot are the parallel brown and cream-colored cloud bands. These run in the direction that Jupiter’s moons move, since the four Galilean moons orbit over Jupiter’s equator. Jupiter, 11 time’s the Earth’s diameter, rotates on its axis in a bit less than 10 hours, though the clouds at the equator rotate faster than those at higher latitudes. It also gives Jupiter a slightly squashed appearance., enhanced by the horizontal stripes. Embedded in one of the dark stripes is the famous Great Red Spot.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Jupiter with red spot

Scott Anttila image of Jupiter from November 14, 2011.

 

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04/30/2018 – Ephemeris – Venus-Earth resonances, and Jupiter & the Moon tonight

April 30, 2018 Comments off

Ephemeris for Monday, April 30th. The Sun rises at 6:34. It’ll be up for 14 hours and 12 minutes, setting at 8:46. The Moon, 1 day past full, will rise at 9:30 this evening.

Jupiter will be near the moon tonight. The gravitational force between the planets produces some interesting resonances in their orbital periods. Venus has three different kinds with the Earth. First, Venus orbits the Sun 13 times in the same time it takes the Earth to orbit the Sun 8 times. This is a 13 to 8 resonance. This sets up the 5 Venus Cycles equaling 8 years resonance the Mayan’s discovered. A Venus cycle of 584 days takes Venus to go from Morning Star to Evening Star and back again. The next one wasn’t discovered until we started to bounce radar signals off Venus. We found it rotates backwards, and very slowly at that. Its rotation with respect to the stars is longer than its year. And it so happens that every passage near the Earth the same side of Venus is facing us.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The Moon and Jupiter

The Moon and Jupiter at 10 p.m. tonight, April 30, 2018. Created using Stellarium.

04/03/2018 – Ephemeris – How to spot Zodiacal Light

April 3, 2018 Comments off

Ephemeris for Tuesday, April 3rd. The Sun will rise at 7:19. It’ll be up for 12 hours and 53 minutes, setting at 8:12. The Moon, 3 days past full, will rise at 11:44 this evening.

Zodiacal light is a faint but towering glow that can be seen after the end of astronomical twilight on a moonless night. It is seen in the west in the evening in late winter and early spring and in the east in the morning in late summer and early autumn. The axis of the glow is the ecliptic, the plane of the Earth’s orbit, indeed that of all the planets, along which lie the constellations of the zodiac. Right now the end of twilight is about 10 p.m. and advancing at a rate of a minute or two each night. The cause of zodiacal light is dust, micron sized dust from comets and asteroids. Most of these lie in the plane of the solar system, which is why zodiacal light is centered on the ecliptic and the constellations of the zodiac and increases in brightness and width toward the Sun.  Spotting Zodiacal Light takes dark adapted eyes,  time and patience.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Zodiacal Light

Much enhanced Zodiacal Light from the my back yard at 9:31 p.m. March 16, 2018, 5 minutes after the official end of astronomical twilight. Canon EOS Rebel T5 18mm f.l., f/3.5, 6 sec. ISO 12,800 . The clouds on the left appear to be illuminated by the lights of the towns of Beulah and Frankfort 20+ miles away.  Note the Pleiades at the top of the image.

 

03/26/2018 – Ephemeris – The Moon will slide below the Beehive star cluster tonight

March 26, 2018 Comments off

Ephemeris for Monday, March 26th. The Sun will rise at 7:34. It’ll be up for 12 hours and 28 minutes, setting at 8:02. The Moon, 2 days past first quarter, will set at 5:34 tomorrow morning.

Tonight the gibbous Moon will be seen among the stars of Cancer the crab. It will just about completely drown Cancer’s dim stars out. That is no exception to one of the famous group of stars in Cancer, the Beehive star cluster. It is going to take binoculars or a small telescope to spot them. The star cluster will be at the 11 o’clock position from the Moon. When looking for the cluster try to keep the Moon out of your field of view. The cluster is about 4 moon-widths away, so aim high and slowly aim those binoculars down. There will be other times in the next few months to catch the Moon near the Beehive, when the Moon will be a not so overwhelming crescent as the cluster moves westward in the evening sky with the rest of the stars.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The Moon and the Beehive Star Cluster

The Moon and the Beehive Star Cluster tonight at 9 p.m. March 26, 2018. The star cluster will be very difficult to spot. Created using Stellarium, however I had to boost the brightness of the stars and eliminate the atmosphere control to darken the sky enough to see the cluster. Good luck!

Cancer the Crab

Cancer the crab finder chart for a dark night. Note the beehive cluster, also known to amateur astronomers as M44, along with other catalog names. Prior to the invention of the telescope this cluster was known as Praesepe which means “Manger”. Created using Stellarium and GIMP.

03/19/2018 – Ephemeris – The dim zodiacal constellation of Cancer the crab

March 19, 2018 Comments off

Ephemeris for Monday, March 19th. The Sun will rise at 7:47. It’ll be up for 12 hours and 6 minutes, setting at 7:54. The Moon, 2 days past new, will set at 10:21 this evening.

At 10 this evening, the faint constellation, and member of the Zodiac, Cancer the crab is located in the south half way between the bright stars Castor and Pollux of the constellation Gemini, high in the south and the bright star Regulus in Leo the lion in the southeast. Cancer is very dim, looking like an upside-down Y or even a K if all its stars can be made out. In the center of Cancer is a fuzzy spot to the unaided eye. In binoculars or a low power telescope this fuzzy spot becomes a cluster of stars. It is the Beehive cluster. At 577 light years away, according to the latest measurements, it is one of the closest star clusters. A week from tonight the Moon will pass below this cluster, by about 4 of its diameters.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Cancer the Crab

Cancer the crab finder chart. Note the beehive cluster, also known to amateur astronomers as M44, along with other catalog names. Prior to the invention of the telescope this cluster was known as Praesepe which means “Manger”. Created using Stellarium and GIMP.

The Beehive

The Beehive star cluster, M44. Its ancient name was the Praesepe or manger when glimpsed by the naked eye. Created using Cartes du Ciel (Skycharts)

03/14/2018 – Ephemeris – A Pi Day look at the bright planets

March 14, 2018 Comments off

Ephemeris for Pi Day, Wednesday, March 14th. The Sun will rise at 7:57. It’ll be up for 11 hours and 50 minutes, setting at 7:47. The Moon, 3 days before new, will rise at 7:15 tomorrow morning.

Pi day: the first three digits of the mathematical constant pi is 3-14. Let’s take our weekly look at the bright planets. All 5 of the naked eye planets are visible now. Three of them are visible this morning. Before it gets light Jupiter will be in the west-southwest, with Mars in the south and Saturn a bit left of the red planet. Jupiter will rise at 12:44 tomorrow morning. Mars will rise at 3:42. And Saturn will rise at 4:19 a.m. In the evening sky Venus will be visible low in the western twilight from about 8:15 p.m. until before it sets at 9:06. Mercury is much dimmer but above and a bit right of Venus, tonight about 8 Moon widths at 1 o’clock from Venus. It will set at 9:26. Mercury will appear higher than Venus in the sky for 6 more nights.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

Morning Planets

The morning planets of Jupiter, Mars and Saturn plus the Moon. Seen at 7 a.m. EDT this morning March 14, 2018. Click on image to enlarge. Created using Stellarium.

Telescopic Jupiter and Saturn

Jupiter and Saturn with their brighter satellites tomorrow morning at 6 a.m. March 8, 2018. They are displayed at the same scale. Saturn in about twice as far as Jupiter. Its disk is a bit smaller than Jupiter’s so it appears about half as large. The extent of the rings appear to be about the same as Jupiter’s diameter. Created using Cartes du Ciel (Sky Charts).

Evening planets

Venus and Mercury, low in the west at 8:15 p.m., March 14, 2018. Created using Stellarium.

Planets at sunset and sunrise of a single night

Planets at sunset and sunrise of a single night starting with sunset on the right on March 14, 2018. The night ends on the left with sunrise on the 15th. Click on the image to enlarge. Created using my LookingUp program.

02/13/2018 – Ephemeris – The Big Dipper as a pointer to other stars and constellations

March 13, 2018 Comments off

Ephemeris for Tuesday, March 13th. The Sun will rise at 7:58. It’ll be up for 11 hours and 47 minutes, setting at 7:46. The Moon, 4 days before new, will rise at 6:42 tomorrow morning.

With the Big Dipper up in the northeastern sky it is a sign that spring is coming. At 9 p.m. The Big Dipper can be used to find other stars and constellations. The Big Dipper’s most famous function is in locating Polaris the North Star. It’s a good way of finding directions at night. The altitude of Polaris, that is angle above the horizon, will give one’s approximate latitude north of the equator. Another constellation that can be found is Leo the lion. It is rising in the east in the evening, but it can also be found from the Big Dipper by imagining that a hole were drilled in the bottom of the bowl to let the water leak out. It would fall on Leo’s back. The Big Dipper can be used to find two more stars, but they have not yet risen.

The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.

Addendum

The Big Dipper

The Big Dipper points to Polaris, the, North Star, and to Leo the lion at 9 p.m., March 13th. In another hour the 4th brightest night-time star Arcturus will appear above the eastern horizon pointed to by the arc of the handle of the Big Dipper. We’ll revisit the Big Dipper next month when Arcturus and Spica will also be found by the use of the Big Dipper. Created using Stellarium and Libre Office.