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09/15/2020 – Ephemeris – The dolphin and the arrow, small summer constellations

September 15, 2020 Comments off

This is Bob Moler with Ephemeris for Tuesday, September 15th. Today the Sun will be up for 12 hours and 30 minutes, setting at 7:52, and it will rise tomorrow at 7:23. The Moon, 2 days before new, will rise at 6:01 tomorrow morning.

Located below the eastern edge of the Summer Triangle of three of the brightest stars in the sky, which is nearly overhead in our sky at 10 p.m., is the tiny constellation of Delphinus the dolphin. Delphinus’ 6 stars in a small parallelogram with a tail, really does look like a dolphin leaping out of the water. The parallelogram itself has the name Job’s Coffin. The origin of this asterism or informal constellation is unknown. Of the dolphin itself: the ancient Greeks appreciated this aquatic mammal as we do, and told stories of dolphins rescuing shipwrecked sailors. There’s another tiny constellation to the right of Delphinus, Sagitta the arrow a small thin group of 5 stars, which represents Cupid’s dart.

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

Addendum

Delphinus and Sagitta finder animation

Delphinus and Sagitta finder animation. Created using Stellarium and GIMP.

09/08/2020 – Ephemeris – The Anishinaabe folk saw a moose where we see Pegasus

September 8, 2020 Comments off

This is Ephemeris for Tuesday, September 8th. Today the Sun will be up for 12 hours and 51 minutes, setting at 8:05, and it will rise tomorrow at 7:15. The Moon, 2 days before last quarter, will rise at 11:14 this evening.

Yesterday I talked a bit about the constellation of Pegasus the flying horse ascendant in the east these September evenings. The Anishinaabe peoples of our area had no horses until after the Europeans arrived, but they did imagine a large four legged mammal here, the Mooz or Moose, spelled M-o-o-z and pronounced something like Moonz*. The Moose is upright, or will be when he is in the south. In the evening now he is in the east, his body is a large square of stars we call the Great Square of Pegasus standing on one corner. From the top star extend his neck and head. His great antlers cover the official constellation of Lacerta the lizard made of a zigzag of unremarkable faint stars. Unlike Pegasus the whole moose made it into the sky.

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

Addendum

Mooz finder animation

Mooz finder animation displaying both Western Pegasus and Lacerta constellations and Anishinaabe Mooz constellation for 10 pm in early September. Credit Stellarium (both star lore images are embedded in Stellarium). The Anishinaabe image is from Ojibwe Giizhig Anung Masinaaigan – Ojibiwe Sky Star Map created by A. Lee, W. Wilson, and C. Gawboy.

*Information on Mooz and its pronunciation can be found in the Ojibwe Peoples Dictionary at https://ojibwe.lib.umn.edu/main-entry/mooz-na. The language of the Ojibwe, Ojibwemowin is another name for Anishinaabemowin, the language of the Anishinaabe peoples.

08/14/2020 – Ephemeris – Seeing the summer Milky Way

August 14, 2020 Comments off

This is Bob Moler with Ephemeris for Friday, August 14th. Today the Sun will be up for 14 hours and 4 minutes, setting at 8:49, and it will rise tomorrow at 6:45. The Moon, 3 days past last quarter, will rise at 2:39 tomorrow morning.

Now is the time the summer Milky Way is displayed to its fullest to the southern horizon. We have a week before the Moon begins to encroach on our dark skies after 10 pm. City folk come to our area and are sometimes fooled by the brightness and expanse of the Milky Way and think it’s a cloud. Yes those are clouds indeed, but they are star clouds. Binoculars will begin to show them to be millions of stars, each too faint to be seen individually to the eye, but whose combined glow give the impression of a luminous cloud. Binoculars are the ideal tool to explore the Milky Way. Objects still too fuzzy can be checked out with a telescope to reveal their true nature. The dark nights of August and September are my favorites.

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

Addendum

August Milky Way sky dome

The summer Milky Way spans the sky dome at 11 pm tonight, August 14, 2020. Created using Stellarium.

 

08/13/2020 – Ephemeris – Sagittarius the archer, morphs into a teapot

August 13, 2020 Comments off

This is Bob Moler with Ephemeris for Thursday, August 13th. Today the Sun will be up for 14 hours and 7 minutes, setting at 8:50, and it will rise tomorrow at 6:44. The Moon, 2 days past last quarter, will rise at 1:53 tomorrow morning.

Due south and low in the sky at 10:30 p.m. now is one of my favorite asterisms the Teapot of the constellation Sagittarius. Sagittarius classically represents a centaur with a bow and arrow aimed at the heart of the constellation Scorpius to its west. I can find the bow and arrow here, but the half man half horse figure of the centaur eludes me. However the stout little teapot of the children’s song is quite obvious, with its base, lid on top, handle to the left and the spout to the right. To make things more realistic the bright Milky Way seems to rise like steam from its spout. As the night goes on the Teapot slides westward and appears to tilt, pouring its tea on the southwestern horizon. Jupiter and Saturn are just to the left of it now.

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

Addendum

Sagittarius-Teapot finder animation

Sagittarius-Teapot finder animation for 10 pm August 13, 2020. Click on the image to enlarge. Created using Stellarium and GIMP.

08/11/2020 – Ephemeris – Tonight is the peak of the Perseid Meteor shower

August 11, 2020 Comments off

This is Bob Moler with Ephemeris for Tuesday, August 11th. Today the Sun will be up for 14 hours and 12 minutes, setting at 8:53, and it will rise tomorrow at 6:42. The Moon, at last quarter today, will rise at 12:46 tomorrow morning.

This evening and tomorrow morning we should see the peak of the Perseid Meteor Shower. There is the expected broad peak of the shower which for us is after sunrise. However the meteoroid stream isn’t monolithic. Each pass of the comet in the inner solar system superimposes its debris on the general stream, so we will have increased activity all night tonight and even into the next few mornings. In general Perseid meteors will be seen to come from the northeast. The evening view will be not hampered by the Moon until it rises at 12:46 am which will drown out the dimmer meteors. The best time to view is from about 10 or 10:30 pm to 12:46 am. The Perseids are the most active meteor shower visible in warm weather, with a possible over 50 meteors per hour.

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

Addendum

My best Perseid photo. From the 70's.

My best Perseid photo. From the 1970’s.

Perseid radiant at 11 pm, August 11th

Perseid radiant at 11 pm, August 11th at the top of the constellation of Perseus, below the W shaped constellation of Cassiopeia. Click on the image to enlarge. Created using Stellarium.

08/06/2020 – Ephemeris – Looking at Saturn through a small telescope

August 6, 2020 Comments off

This is Bob Moler with Ephemeris for Thursday, August 6th. Today the Sun will be up for 14 hours and 25 minutes, setting at 9:01, and it will rise tomorrow at 6:36. The Moon, 3 days past full, will rise at 10:55 this evening.

The planet Saturn is just to the left or east of Jupiter in the southeastern evening sky. In steadily held binoculars Saturn is not star-like, but it’s not round either. It’s a small oval dot. The oval or ellipse is due to its rings of small icy bodies that orbit the planet over its equator. A telescope in needed to appreciate those rings to their fullest extent. Saturn’s largest moon Titan will be visible tonight in line with the eastern extent of the rings. Saturn, like the Earth has an axial tilt. In its case it’s 26 degrees. And the rings orbit over Saturn’s equator. So as Saturn orbits the Sun in it’s nearly 30 year orbit the aspect of the rings change over that period. The ellipse shape of the rings are getting thinner now, and in 5 years they will be seen to disappear for a bit.

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

Addendum

Saturn's rings change.

How the appearance of the rings change as Saturn orbits the Sun. The rings were at their widest in 2017. They are closing and will be edge-on again in 2025. When edge-on the rings literally disappear. Despite being 150,000 miles wide as we look at the planet, they are generally less than 66 feet (20 meters) in thickness. Credit: NASA Hubble.

08/05/2020 – Ephemeris – Let’s look at the naked-eye planets for this week

August 5, 2020 Comments off

This is Bob Moler with Ephemeris for Wednesday, August 5th. Today the Sun will be up for 14 hours and 28 minutes, setting at 9:02, and it will rise tomorrow at 6:35. The Moon, 2 days past full, will rise at 10:32 this evening.

Let’s look at the naked-eye planets for this week. Jupiter and Saturn are both low in the southeastern sky in the evening. Jupiter is the very bright one. To the left of it will be Saturn. They now seem to be separating a bit due to the Earth’s motion now, but they will cross paths in December. Both planets will be up most of the night with Jupiter setting first at 4:33 am tomorrow morning and Saturn following at 5:14 am. The next planet visible will be Mars which will rise at 11:43 pm. Its now down to 57.7 million miles (92.9 million km) away, as the Earth slowly overtakes it at the rate of about 3.4 million miles (5.5 million km) a week. Brilliant Venus will rise at 3:09 am in the east-northeast as our Morning Star.

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

Addendum

Evening planets

Evening planets Jupiter and Saturn seen in the southeast along with the constellations of Sagittarius (looks like a teapot) and Scorpius at 10 pm, about 45 minutes after sunset tonight August 5, 2020. Click on the image to enlarge. Created using Stellarium.

Binocular Moon

The Moon as it might be seen in binoculars at 11 pm tonight August 5, 2020, about a half hour after it rises. Created using Stellarium.

Morning planets

The morning planets and the Moon as seen at 5:30 am or about an hour before sunrise tomorrow morning August 6, 2020. Note the winter constellation of Orion rising in the east with its two brightest stars Betelgeuse and Rigel labeled. Click on the image to enlarge. Created using Stellarium.

Telescopic planets

The planets as seen in a telescope (north up) with the same magnification tonight and tomorrow, August 5/6, 2020. Apparent diameters: Jupiter, 46.85″; Saturn, 18.40″, rings, 42.85″ at 10 pm. Mars, 15.26″, and Venus 25.46″. At 5:30 am. Mars also displays an enlargement showing surface detail. The ” symbol means seconds of arc (1/3600th of a degree.) 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 August 5, 2020. The night ends on the left with sunrise on the 6th. Click on the image to enlarge. Created using my LookingUp program.

08/04/2020 – Ephemeris – Viewing Jupiter and its moons with binoculars or small telescope

August 4, 2020 Comments off

This is Ephemeris for Tuesday, August 4th. Today the Sun will be up for 14 hours and 30 minutes, setting at 9:03, and it will rise tomorrow at 6:34. The Moon, 1 day past full, will rise at 10:06 this evening.

The planet Jupiter is a fine object to view with just about any optical aid be it a pair of binoculars, spotting scope or telescope. In binoculars, if held steady or mounted on a tripod Jupiter itself will no longer look star-like, but a tiny disk. Several of Jupiter’s moons can also be seen. With a telescope four of them can be seen, the same four Galileo discovered 410 years ago. At 10 pm they will be in the same order of distance from the planet that they actually are. The two nearest will be on the west side of the planet Io the closest, the Europa the next moon out. On the east side there is the third farthest Ganymede, and farthest out is Callisto. Their orbits are nearly edge on to us, so they shuttle from one side to the other of the planet.

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

Addendum

Jupiter and its Galilean moons for tonight and tomorrow night

Jupiter and its Galilean moons for tonight and tomorrow night August 4 & 5, 2020. Those moons really move from night to night. This is shown north at the top, east to the left. Based on telescope design the image presented could be inverted, mirror image or both. Created using Cartes du Ciel (Sky Charts).

Due to the lack of time (59 seconds) I could only cover the moons. I’ll address Jupiter’s cloud features at another time. Can’t wait? Here’s a link: https://bobmoler.wordpress.com/2018/05/22/05-22-2018-ephemeris-seeing-detail-on-the-face-of-jupiter-with-a-small-telescope/

07/27/2020 – Ephemeris – Two meteor showers, one near peak, another just starting

July 27, 2020 Comments off

This is Ephemeris for Monday, July 27th. Today the Sun will be up for 14 hours and 49 minutes, setting at 9:13, and it will rise tomorrow at 6:25. The Moon, at first quarter today, will set at 1:18 tomorrow morning. | Tonight’s first quarter Moon will hinder the viewing of Comet NEOWISE and the Southern Delta Aquariid meteor shower until after moonset at 1:18 am. The meteor shower radiant will start out low southeastern sky and end up in the south as twilight brightens. It is usually during this meteor shower that the first Perseid meteors show up. The Perseid meteor shower is the most watched meteor shower of the year. It’s great every year except when there’s a bright Moon. This year the Perseids will reach their peak hourly numbers on the morning of August 12th after sunrise, unfortunately. The Moon will interfere after it rises at 12:46 am, which leaves two hours of moonless meteor viewing earlier on the evening of the 11th.

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

Addendum

Sky Dome at 2 am tomorrow morning

The Sky Dome at 2 am tomorrow morning July 28, 2020 at 2 am. DAqr is the approximate location of the Southern Delta Aquariid meteor shower and PerR is the approximate location of the Perseid radiant. Created using my LookingUp program.

Comet NEOWISE in the evening for July 14, 2020 to July 31, 2020

Comet NEOWISE in the evening for July 14, 2020 to July 31, 2020. The horizon is for July 14th at 11 p.m. Click on the image to enlarge. Created using Cartes du Ciel (Sky Chart).

07/24/2020 – Ephemeris – Where did Comet NEOWISE come from?

July 24, 2020 Comments off

This is Ephemeris for Friday, July 24th. Today the Sun will be up for 14 hours and 56 minutes, setting at 9:17, and it will rise tomorrow at 6:21. The Moon, 3 days before first quarter, will set at 11:58 this evening.

Ephemeris – Over the weekend Comet C/2020 F3 (NEOWISE) will be moving toward the west in the sky as it continues dimming as the Moon gets brighter. This make for a real challenge to spot. So where do comets hang out when they’re not buzzing the Sun? NEOWISE came in from 709 times the Earth’s distance from the Sun. That’s 66 billion miles (106 billion km), and a round trip that takes 6,800 years to complete. That aphelion point is between where the Kuiper belt of dwarf planets like Pluto and Eris hang out and the more distant Oort Cloud of pristine comets. Comets are leftovers from the formation of the solar system, four and a half billion years ago. The cold that far out preserves the volatile ices until a passing star sends them inward.

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

Addendum

Comet NEOWISE finder chart

Comet NEOWISE finder chart for tonight July 24, 2020 at 11 pm or about an hour and a half after sunset looking northwest under the Big Dipper. The Moon is brightening up the sky and the comet is getting dimmer. Stellarium shows the comet at around 4th magnitude. I admit I fudged the formula in the app for the comet brightness, using the values from Seiichi Yoshida’s website entry for C/2020 F3 (NEOWISE). Created using Stellarium.

Seiichi Yoshida’s Weekly Information about Bright Comets: http://www.aerith.net/comet/weekly/current.html.