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Archive for March, 2019

03/29/2019 – Ephemeris – The Stars Mizar and Alcor in the Big Dipper

March 29, 2019 Comments off

Ephemeris for Friday, March 29th. Today the Sun will be up for 12 hours and 36 minutes, setting at 8:06, and it will rise tomorrow at 7:27. The Moon, 1 day past last quarter, will rise at 5:03 tomorrow morning.

The most interesting star in the Big Dipper is Mizar and its dim companion Alcor. It is the second star from the end of the handle, where the bend in the handle takes place. Folks with good vision can see the dimmer star right next to Mizar. In ancient times it was used as an eye test for visual acuity for warriors. As such it was known as the “Horse and the Rider”. Mizar is second magnitude, in the second rank of star brightness invented by the Greek astronomer Hipparchus in the 2nd century BC. He ranked stars in 6 classes, from first magnitude for the brightest to 6th for the dimmest visible to the naked eye. Alcor comes in at 4th magnitude. It does suffer a bit by being very close to Mizar which is 6 times brighter.

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

 

Categories: Ephemeris Program, stars

03/28/2019 – Ephemeris – The Big Dipper as seen by some other countries

March 28, 2019 Comments off

Ephemeris for Thursday, March 28th. Today the Sun will be up for 12 hours and 33 minutes, setting at 8:05, and it will rise tomorrow at 7:29. The Moon, at last quarter today, will rise at 4:21 tomorrow morning.

The Big Dipper is climbing up the northeastern sky at 9:30 in the evening, it’s seven stars shining brightly. The Big Dipper is not an actual constellation, recognized internationally. It’s part, the hind part, of Ursa Major, the great bear. The Big Dipper is an asterism or informal constellation. It is a distinctly North American constellation. For fugitive slaves, fleeing the southern states in the days before the Civil War, the Drinking Gourd, as they called it, showed the direction north to freedom. In England the dipper stars become the Plough, or Charles’ Wain (Charlemagne’s Wagon). In France, known for culinary delights it was the saucepan, or the cleaver. Many cultures saw what was familiar to them in these seven bright stars.

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

Addendum

Big Dipper as seen by different cultures

Cultural views of the Big Dipper as an Animation: Big Dipper/Sauce Pan, Plough (plow), Charle’s Wain (Charlemagne’s wagon), Cleaver.

03/27/2019 – Ephemeris – Looking for and at the bright planets for this week

March 27, 2019 Comments off

Ephemeris for Wednesday, March 27th. Today the Sun will be up for 12 hours and 30 minutes, setting at 8:03, and it will rise tomorrow at 7:31. The Moon, 1 day before last quarter, will rise at 3:33 tomorrow morning.

Let’s look at the planets for this week. Mars will be in the western sky this evening, below the Pleiades, or Seven Sisters, star cluster. It will pass to the left of the Pleiades Saturday night. Tonight, however, it will set at 12:34 a.m. In the morning sky we have Jupiter which will rise tomorrow at 2:29 a.m. in the east-southeast. It is second to Venus in brightness. Saturn will be next to rise at 4:14 a.m., also in the east-southeast. Venus will rise at 6:20 a.m. also in the east-southeast. By 7 in the morning they will be strung out from the southeast to the south, with the last quarter Moon between Jupiter and Saturn. The Moon will pass Saturn early Friday morning before it rises and will be seen then to the left of Saturn.

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

Addendum

Mars passing the Pleiades

Mars tiptoeing past the Pleiades nightly from March 26th to April 1st, 2019. Looking west. Created using Stellarium and GIMP.

Morning planets

Morning planets and the Moons at 6:45 a.m. tomorrow March 28, 2019. Click on the image to enlarge. Created using Stellarium.

Binocular Moon

The moon as it might appear in binoculars tomorrow morning, March 28, 2019. Created using Stellarium.

Telescopic planets

Jupiter, Saturn and Venus with the same magnification at 6:45 a.m. tomorrow morning March 28, 2019. Created using Cartes du Ciel (Sky Charts).

Planets and the Moon on a single night

Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on March 27, 2019. The night ends on the left with sunrise on the 28th. Click on the image to enlarge. Created using my LookingUp program.

03/26/2019 – Ephemeris – Mars is approaching the Pleiades this week

March 26, 2019 Comments off

Ephemeris for Tuesday, March 26th. Today the Sun will be up for 12 hours and 27 minutes, setting at 8:02, and it will rise tomorrow at 7:33. The Moon, 2 days before last quarter, will rise at 2:38 tomorrow morning.

Daylight time and spring time are catching up with us with the Sun setting now just after 8 p.m. By 9 p.m. tonight the brighter stars appear and most of the well known constellations will be recognizable. Looking off to the west at that time the famous star group of the Pleiades, or Seven Sisters will appear. Folks with good eyesight can see six or maybe even seven of its stars. Tonight, right below the Pleiades is a bright reddish star. It would be the 22nd of the first magnitude stars, except it’s not a star. It’s a wanderer, according to the ancient Greeks, one of seven*. They called it Ares the god of war. The Romans turned it into Mars. Over the week Mars will be closing in and passing by the Pleiades this weekend.

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

Addendum

Pleiades, Mars, zodiacal light

The western sky at 10:22 last night March 25, 2019. Mars appears below the Pleiades in zodiacal light. Credit, mine – Canon EOS Rebel T5 18mm f.l., f/3.5, 8 sec. ISO 12,800.

Mars passing the Pleiades

Mars tiptoeing past the Pleiades nightly from March 26th to April 1st, 2019 at 9 p.m. Looking west. Created using Stellarium and GIMP.

The letter V of stars to the left of the Pleiades is the Hyades, in mythology the half sisters to the Pleiades.  It is also the face of Taurus the bull.

* We get the word planet from the Greek planētes meaning wander.  Five are the classical planets, Mercury, Venus, Mars, Jupiter, and Saturn.  The other two are the Sun and Moon.  The other celestial objects were the fixed stars.  Other things that appear in the sky, like comets, novae and meteors were thought to be in the Earth’s atmosphere.

03/25/2019 – Ephemeris – Zodiacal light is visible in the west again

March 25, 2019 Comments off

Ephemeris for Monday, March 25th. Today the Sun will be up for 12 hours and 24 minutes, setting at 8:01, and it will rise tomorrow at 7:35. The Moon, 3 days before last quarter, will rise at 1:37 tomorrow morning.

With the bright moon out of the sky for nearly two weeks it’s time to look for the zodiacal light. It’s is a faint but towering glow that can be seen after the end of astronomical twilight on moonless nights. 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 apparent annual path of the Sun in the sky, along which lie the constellations of the zodiac. Right now the end of astronomical twilight is about 9:45 p.m. and advancing at a rate of a minute or two each night. Go to a spot with a dark western sky, no big cities or towns out that way. Zodiacal light is caused by dust spread out around the Sun.

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. Note the Pleiades top left of center and the constellation of Ares below and right of center. 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.

Added ecliptic line

I’ve added the approximate ecliptic line from a Stellarium view of the same date and time.

03/22/2019 – Ephemeris – The Great Underwater Panther

March 22, 2019 Comments off

Ephemeris for Friday, March 22nd. Today the Sun will be up for 12 hours and 14 minutes, setting at 7:57, and it will rise tomorrow at 7:40. The Moon, 2 days past full, will rise at 10:07 this evening.

The Anishinabe peoples of the Great Lakes Region, which includes the Ottawa, Chippewa and Ojibwe Indians have one constellation of winter I know of. It is The Winter Maker which uses many of Orion’s stars and whose arms stretch from Aldebaran in Taurus the bull to Procyon the Little Dog Star, embracing the whole of the winter sky. Now that spring is here he is sinking into the west. The first constellation of spring is Curly Tail, or the Great Underwater Panther. Which uses the stars of Leo the lion’s backward question mark as its tail and the small knot of stars that are the head of Hydra the water snake below Cancer the crab as its head. Keep off the thinning ice or break through and be snatched by the great panther that lives below.

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

Addendum

Great Underwater Panther animation

Great Underwater Panther finder animation relating western to Anishinaabe constellations for 9 p.m. March 22, 2019. Click on the image to enlarge.  Created using Stellarium.

The constellation art is part of the latest versions of Stellarium. Ojibwe (Anishinaabe) constellation art by Annette S Lee and William Wilson from Ojibwe Sky Star Map Constellation Guide, by A. Lee, W Wilson, C Gawboy, J. Tibbetts.  ISBN 978-0-615-98678-4.

03/21/2019 – Ephemeris – Are day and night really equal at the equinoxes?

March 21, 2019 Comments off

Ephemeris for Thursday, March 21st. Today the Sun will be up for 12 hours and 11 minutes, setting at 7:56, and it will rise tomorrow at 7:42. The Moon, 1 day past full, will rise at 8:52 this evening.

What we had yesterday was the vernal equinox, the start of spring. The word equinox means “equal night”. Yesterday’s daylight hours were 12 hours and 8 minutes. What’s with the 8 minutes? The rising or setting Sun is a mirage. The Earth’s atmosphere acts like a lens and makes the Sun appear higher in the sky than when it is when near the horizon. When the bottom edge of the Sun touches the horizon the Sun is actually still completely below the horizon geometrically. If the Earth had no atmosphere sunrises would occur 4 minutes later, and sunsets would occur 4 minutes earlier around here. That would completely correct the 12 hour 8 minutes daylight time of yesterday to 12 hours even.

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

Addendum

Atmospheric Refraction

How the atmosphere bends the light of the Sun or Moon rising or setting to appear higher than it actually is. Credit Francisco Javier Blanco González, 2017.

I took a look at the related atmospheric refraction effect last month: https://bobmoler.wordpress.com/2019/02/19/02-19-2019-ephemeris-the-moon-aint-just-super-near-the-horizon/.