Archive

Archive for the ‘Observing’ Category

12/19/2018 -Ephemeris – The Bright planets and a departing comet for this week

December 19, 2018 Comments off

Ephemeris for Wednesday, December 19th. The Sun will rise at 8:15. It’ll be up for 8 hours and 48 minutes, setting at 5:04. The Moon, 3 days before full, will set at 5:34 tomorrow morning.

Let’s look at the bright planets for tonight. In the evening sky we have Mars still visible, but Saturn is lost in the bright twilight. It will pass conjunction with the Sun on New Years day. Mars will be due south at 6:19 p.m., and it will set at 12:08 a.m. Mars is moving eastward, crossing the constellation of Aquarius until the 21st, when it enters Pisces. Comet Wirtanen is moving northward, to the left of the Pleiades and fading as the moonlight gets brighter. On the 23rd at 9 p.m. it will be a degree and a half, that’s 3 moon widths below and a bit left of the star Capella. Venus, our brilliant morning star, will rise at 4:20 a.m. in the east-southeast. The planets Jupiter and Mercury will be low on the southeastern horizon by 7 a.m. tomorrow..

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

Addenda

Bright planets and the Moon

Evening planets

Mars, and the Moon at 8 p.m. tonight December 19, 2018. Click on image to enlarge. Created using Stellarium.

Binocular Moon

The waxing gibbous Moon as it should appear tonight in binoculars. Created using Stellarium.

Morning planets

Morning planets Venus, Mercury and Jupiter on December 20, 2018, 7 a.m.. Created using Stellarium.

Telescopic Venus

Telescopic view of Venus tomorrow morning December 20, 2018. Created using Stellarium.

Planets and the Moon on a single night

Planets, two comets and the Moon at sunset and sunrise of a single night starting with sunset on the right on December 19, 2018. The night ends on the left with sunrise on the 20th. Click on the image to enlarge. Created using my LookingUp program.

Comets

Comet C/2018 V1

Comet C/2018 V1 (Machholz-Fijikawa-Iwamoto) in twilight starting tonight December 19, 2018. This comet is basically invisible in the evening twilight of 6 p.m. on the rest of the nights because the stars in the field will set 4 minutes earlier each successive evening. The latest magnitude observed is two magnitudes brighter than shown here. Created using Cartes du Ciel (Sky Charts).

Comet 46P/Wirtanen

Comet 46P/Wirtanen positions for the next week in a bright moonlit sky. Positions are marked with month-date and magnitude. The observations are about 5.5 magnitudes brighter than shown here. Star field position is for 9 p.m. on the 19th. Click on the image to enlarge. Created using Cartes du Ciel (Sky Charts).

Advertisements

12/18/2018 – Ephemeris – My observations and what to expect from Comet Wirtanen

December 18, 2018 Comments off

Ephemeris for Tuesday, December 18th. The Sun will rise at 8:15. It’ll be up for 8 hours and 48 minutes, setting at 5:03. The Moon, 3 days past first quarter, will set at 4:23 tomorrow morning.

This past weekend the skies finally cleared so I could see and photograph Comet Wirtanen at its brightest and closest to the Earth. The Moon was interfering and will be making the sky brighter until this next weekend. Also the Moon will be moving toward the comet, coming closest to it on the 20th. The comet is rapidly moving away from the Earth, so its brightness is dropping as the skies brighten. Last weekend I could not say that I saw it with the naked eye. It was visible in my 10X50 binoculars as a faint smudge. The comet had no discernible tail. Even though it’s living up to its magnitude estimates, the problem is that the comet’s brightness is spread over a large area, making its surface brightness so much less than a star of the same magnitude.

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

Addendum

Comet Wirtanen and the Pleiades

Comet Wirtanen below and the Pleiades above at 9:24 p.m. EST, December 14, 2018. Canon EOS Rebel T5, f/5.5, 30 second., ISO 3200, fl 55mm, tracking.  I processed this image with GIMP. increasing the contrast and removing some of the moonlight.  The greenish coma (head) is due to carbon (C2) emissions common in comets.

For more comet photographs go to http://spaceweather.com/.

12/15/2018 – Ephemeris Extra – Finally the skies cleared and I got a photograph of Comet Wirtanen

December 15, 2018 Comments off
Comet Wirtanen and the Pleiades

Comet 46P/Wirtanen and the Pleiades. 9:24 p.m. EST, December 14, 2018. Canon EOS Rebel T5, f/5.5, 30 sec., ISO-3200, fl 55mm, tracking.  Click on the image to enlarge.  Credit Bob Moler.

Finally, the skies cleared.  The last time we had clear skies was early in the evening on the 8th. Our family went to the Ballet that evening at Interlochen Center for the Arts, and by the time I got back and dressed to go outside and observe the comet, it had clouded up.  The Ballet was wonderful, by the way.

Anyway, Comet 46P/Wirtanen as a few hours ago was greatly hampered by the nearly first quarter Moon.  And it’s going to get worse as the moon’s phase gets fuller.  I thought I could see it in with the naked eye.  It was visible in binoculars.  As you can see it did photograph well.  I processed the image with GIMP to increase contrast, and reduce the background moonlight.  There is no discernible tail visually or in this photograph.  Longer exposures in a dark sky do show a faint ion tail.  Remember this is a short period comet, and has been around the Horn (perihelion) innumerable times.  It orbits the Sun from just inside Jupiter’s orbit to just outside Earth’s orbit every 5.4 years.

Happy comet hunting!

12/05/2018 – Ephemeris – The bright planets and a comet tonight

December 5, 2018 Comments off

Wednesday, December 5th. The Sun will rise at 8:04. It’ll be up for 8 hours and 58 minutes, setting at 5:02. The Moon, 2 days before new, will rise at 7:08 tomorrow morning.

Let’s look at the bright planets for tonight. In the evening sky we have Mars, but are about to lose Saturn. Saturn will be briefly visible very low in the southwestern sky from about 5:45 p.m. until it sets at 6:46 p.m. Mars will be in the south as the skies darken tonight. Mars will be due south at 6:41 p.m., and it will set at 12:13 a.m. Mars is moving eastward, crossing the constellation of Aquarius until the 21st, then it enters Pisces. Comet Wirtanen is moving northward, below and right of the V of stars that’s the head of Taurus the bull, and should be an excellent binocular object. Venus, our brilliant morning star, will rise at 4:24 a.m. in the east-southeast. The blue-white star Spica is still off to the right and a bit above it.  Mercury will rise at 6:31 a.m. and might be spotted after that.  Jupiter is near the Moon tomorrow morning, rising at 7:24 only 40 minutes before the Sun.

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

Addenda

The planets

Evening planets

Mars, and Saturn seen at 5:45 p.m. tonight December 5, 2018. Created using Stellarium.

Morning planets

Morning planets Venus and Mercury. Jupiter is about to rise at 7:15 a.m. December 6, 2018. Created using Stellarium.

Telescopic Venus

Telescopic view of Venus tomorrow morning December 6, 2018. Created using Stellarium.

Planets and the Moon on a single night

Planets, one comet and the Moon at sunset and sunrise of a single night starting with sunset on the right on December 5, 2018. The night ends on the left with sunrise on the 6th. Click on the image to enlarge. Comet Wirtanen is very close to opposition and to the south, so it rises after sunset and sets before sunrise. Created using my LookingUp program.

Bright comets

Comet C/2018 V1

Comet C/2018 V1 (Machholz-Fijikawa-Iwamoto) in twilight starting tonight November 28, 2018. The comet won’t climb that dramatically at 6 p.m. on the rest of the nights because the stars in the field will set 4 minutes earlier each successive evening. The latest magnitude estimate of the comet on December 8 is 5.9, two magnitudes brighter than shown here. Created using Cartes du Ciel (Sky Charts).

Comet Wirtanen

Comet 46P/Wirtanen positions for the next week. Positions are marked with month-date and magnitude. The latest magnitude prediction for December 1st is 3.7, 5.4 magnitudes brighter than shown here. The comet may make magnitude 3 by mid-December. Star field position is for 9 p.m. on the 28th. Click on the image to enlarge. Created using Cartes du Ciel (Sky Charts).

12/03/2018 – Ephemeris – Comet Wirtanen should be bright enough for the naked eye or binoculars this month

December 3, 2018 Comments off

Ephemeris for Monday, December 3rd. The Sun will rise at 8:02. It’ll be up for 9 hours and 1 minute, setting at 5:03. The Moon, half way from last quarter to new, will rise at 4:56 tomorrow morning.

Beside Comet Machholz-Fujikawa-Iwamoto which I talked about last Thursday and should be at peak brightness about now in the western twilit sky, we have another comet, this one Comet 46P/Wirtanen is brightening in the east in the evening. Wirtanen is a member of the Jupiter family of comets, whose 5.44 year orbit of the Sun takes it from just outside the Earth’s orbit to just inside Jupiter’s orbit. This time around it will come as close as 7.1 million miles of the Earth. As of Thanksgiving the comet was 100 times brighter than its nominal expected brightness. I don’t know if it will stay that way. It has a history of outbursts. If it keeps it up Wirtanen could be as bright as the Pleiades stars when it passes them on the 16th.

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

Addendum

Comet 46P/Wirtanen in December 2018

The path of Comet 46P/Wirtanen from November 21, 2018, to January 1, 2019. The labels are month, date, and expected magnitude. Click on the image to enlarge. Created using Cartes du Ciel (Sky Charts).

Check back every Wednesday at least where Comet Wirtanen will be past of the planet report.  I’ll be covering the comet on other days throughout the month.  Also check  Seiichi Yoshida’s Weekly Information about Bright Comets: http://www.aerith.net/comet/weekly/current.html

11/29/2018 – Ephemeris – A potentially bright comet was discovered earlier this month

November 29, 2018 Comments off

Ephemeris for Thursday, November 29th. The Sun will rise at 7:57. It’ll be up for 9 hours and 6 minutes, setting at 5:04. The Moon, at last quarter today, will rise at 12:17 tomorrow morning.

Three amateur astronomers Don Machholz of the US and by Shigehisa Fujikawa and Masayuki Iwamoto of Japan independently discovered a comet November 7th that bears their names. Now through next week or so ,it will be visible in the western sky in evening twilight. The comet has been rapidly brightening, much more rapidly than expected. It could theoretically be bright enough to spot with the naked eye by Sunday or Monday, but it must compete with evening twilight low in the western to southwestern sky. Comets are unpredictable in their brightness and appearance. As David Levy of Comet Shoemaker-Levy 9 fame once said: “Cats and comets have tails and do exactly what they want”. Check here for updates.

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

Addendum

Comet C/2018 V1
Comet C/2018 V1 (Machholz-Fijikawa-Iwamoto) in twilight starting last night November 28, 2018. The comet won’t climb that dramatically at 6 p.m. on the rest of the nights because the stars in the field will set 4 minutes earlier each successive evening. The latest magnitude estimate of the comet on December 1 is 5.2, two magnitudes brighter than shown here. Created using Cartes du Ciel (Sky Charts).

11/09/2018 – Ephemeris – The Great Andromeda Galaxy

November 9, 2018 Comments off

Ephemeris for Friday, November 9th. The Sun will rise at 7:31. It’ll be up for 9 hours and 49 minutes, setting at 5:21. The Moon, 2 days past new, will set at 7:03 this evening.

In the south at 9, this evening can be found a large square of stars, the Great Square of Pegasus the flying horse, flying upside down to the right. What looks like its hind legs stretching to the left from the upper left corner star is another constellation, Andromeda the chained princess. She is seen in the sky as two diverging curved strings of stars that curve upward. She was rescued by the hero Perseus, a nearby constellation, riding Pegasus. Andromeda’s claim to astronomical fame is the large galaxy seen with the unaided eye just above the upper line of stars. The Great Andromeda Galaxy is 2.5 million light years away. To the naked eye the galaxy appears as a small smudge of light. In binoculars the galaxy is a delicate spindle of light.

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

Addendum

Great Andromeda Galaxy finder chart
Great Andromeda Galaxy finder chart. Created using Stellarium and GIMP.
The Great Andromeda Galaxy (M31). Image taken by Scott Anttila.
The Great Andromeda Galaxy (M31) with two of its satellite galaxies M32 and M110. Image taken by Scott Anttila.