09/20/2017 – Ephemeris – Looking for the bright planets
Ephemeris for Wednesday, September 20th. The Sun will rise at 7:27. It’ll be up for 12 hours and 15 minutes, setting at 7:43. The Moon is new today, and won’t be visible.
Let’s take our weekly look at the bright planets. Jupiter is really low in the west-southwest after sunset setting in twilight at 8:47 p.m. Saturn can be seen low in the southwest tonight. The reddish star Antares is below and right of Saturn before it sets at 10:18 p.m. Saturn’s rings are spectacular in telescopes. With the demise of the Cassini spacecraft orbiting Saturn for the last 13 years, there is no telescope closer to Saturn than yours. The planet will set at 11:35 p.m. In the morning sky, brilliant Venus will rise at 5:03 a.m. in the east-northeast. The first magnitude star Regulus in Leo the lion will be to the upper right of it. Dim Mars will rise in the east-northeast at 5:50 a.m. followed by the brighter Mercury which will rise at 6:12 a.m.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The setting Jupiter and Saturn at 8:15 p.m., September 20, 2017. Created using Stellarium. Click on the image to enlarge.
Saturn and constellations in dark skies at 9 p.m. September 20, 2017. Created using Stellarium. Click on the image to enlarge.
Saturn and its brightest moons overnight September 20/21, 2017. Created using Cartes du Ciel (Sky Charts).
Morning planets close up at 6:30 a.m. September 21, 2017. Created using Stellarium.
Planets at sunset and sunrise of a single night starting with sunset on the right on September 20, 2017. The night ends on the left with sunrise on the 21st. Click on the image to enlarge. Created using my LookingUp program.
09/19/2017 – Ephemeris – The Great Rift
Ephemeris for Tuesday, September 19th. The Sun will rise at 7:26. It’ll be up for 12 hours and 18 minutes, setting at 7:45. The Moon, 1 day before new, will rise at 7:43 tomorrow morning.
High overhead the Milky Way is seen passing through the Summer Triangle of three bright stars. Here we find the Milky Way split into two sections. The split starts in the constellation of Cygnus the Swan or Northern Cross very high in the east. The western part of the Milky Way ends southwest of the Aquila the eagle. This dark dividing feature is called the Great Rift. Despite the lack of stars seen there, it doesn’t mean that there are fewer stars there than in the brighter patches of the Milky Way. The rift is a great dark cloud that obscures the light of the stars behind it. Sometimes binoculars can be used to find the edges of the clouds of the rift, as stars numbers drop off suddenly. This is especially easy to spot in Aquila the eagle.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The Great Rift in the Milky Way. Created using Stellarium.
09/18/2017 – Ephemeris – The constellation of the shield
Ephemeris for Monday, September 18th. The Sun will rise at 7:25. It’ll be up for 12 hours and 21 minutes, setting at 7:46. The Moon, 2 days before new, will rise at 6:35 tomorrow morning.
In the evening sky, in the south after it gets dark can be seen part of the Milky Way. There is actually a constellation here located between Sagittarius the archer, which really looks like a teapot, below and Aquila the eagle above. It’s Scutum the shield of John Sobieski the Polish king who stopped the advance of the Turks at Kalenberg in 1683. Scutum is the only official constellation I know of which is related to a real person. The Polish half of me is very proud. However the stars here are so dim and embedded in the glow of the Milky Way as to be nearly impossible to discern. Scutum lies in one of the richest portions of the Milky Way, wonderful to scan with binoculars and telescopes for star clusters and nebulae or clouds of dust and gas.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Scutum Finder Chart animation. For 9 p.m. September 18, 2017. Created using Stellarium and GIMP. Click on image to enlarge.
Deep sky objects in Scutum and surrounding area. September 2017. Created using Stellarium. Click on image to enlarge.
09/15/2017 – Ephemeris – Two local astronomy events tomorrow
Ephemeris for Friday, September 15th. The Sun will rise at 7:21. It’ll be up for 12 hours and 30 minutes, setting at 7:52. The Moon, 2 days past last quarter, will rise at 3:10 tomorrow morning.
There are two local astronomical events tomorrow. Tomorrow the Leland Heritage Celebration will take place from 10 a.m. to 4 p.m. at Fish Town in Leland. The Grand Traverse Astronomical Society will be there to show the Sun through member’s telescopes and give out NASA items for the kids. We’ll exhibit pictures gained from last month’s total solar eclipse. Then starting at 9 p.m. the crew will be at Northwestern Michigan College’s Rogers Observatory for a star party, viewing Saturn and the wonders of the Milky Way including star clusters and nebulae of clouds of gas and dust that mark locations of either the birth or death of stars. Rain will affect the Leland event. The observatory is located on Birmley Road.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
GTAS telescopes at Leland Heritage Celebration in 2011.
09/14/2017 – Ephemeris – Cassini will go out in a blaze of glory tomorrow morning
Ephemeris for Thursday, September 14th. The Sun will rise at 7:20. It’ll be up for 12 hours and 33 minutes, setting at 7:54. The Moon, 1 day past last quarter, will rise at 2:05 tomorrow morning.
Just about 24 hours from now the Cassini spacecraft will end its 20 year mission to Saturn and its 13 years of orbiting the planet. Monday, 4 days ago, it passed the great moon Titan for the last time, giving it one last gravitational boost into a suicidal plunge into Saturn’s atmosphere. At 7:55 tomorrow morning EDT (11:55 UTC), Cassini is expected to lose its stabilization in the thin upper atmosphere or Saturn and lose its connection with the Earth. It is expected to burn up, traveling at 70,000 miles an hour to become a part of the planet it investigated for 13 years. Instead of recording data for transmission to Earth later, it will be taking real-time atmospheric sampling, transmitting immediately up to the very end.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
An artist’s visualization of Cassini slipping between the rings and the atmosphere of Saturn. Credit NASA/JPL.
Here’s a link to yesterday’s news conference at JPL on the end of the Cassini Mission: https://youtu.be/gs-dscW95PE.
Link to Emily Lakdawalla’s Planetary Society post on the final days of Cassini including NASA TV coverage: http://www.planetary.org/blogs/emily-lakdawalla/2017/0911-cassini-eom-timeline.html.
09/13/2017 – Ephemeris – Looking for the bright planets this week
Ephemeris for Wednesday, September 13th. The Sun will rise at 7:19. It’ll be up for 12 hours and 36 minutes, setting at 7:56. The Moon, at last quarter today, will rise at 1:05 tomorrow morning.
Let’s take our weekly look at the bright planets. Jupiter is sinking really low in the west-southwest setting before the end of twilight. Jupiter will set at 9:11 p.m. Saturn can be seen moving from the south-southwest to the southwest tonight. The reddish star Antares is below and right of Saturn. Saturn’s rings are spectacular in telescopes. The planet will set at midnight. In the morning sky, brilliant Venus will rise at 4:48 a.m. Mercury will rise at 5:46 and Mars will rise at 5:54 a.m.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The setting Jupiter and Saturn at 8:30 p.m., September 13, 2017. Created using Stellarium. Click on image to enlarge.
Saturn and its brightest moons overnight September 13/14, 2017. Created using Cartes du Ciel (Sky Charts).
Planets in the morning sky at 6:30 a.m. September 14, 2017. Created using Stellarium. Click on the image to enlarge.
Morning planets close up at 6:30 a.m. September 14, 2017. Created using Stellarium.
The fat crescent Moon as it might be seen in binoculars at 6:30 a.m. September 14, 2017. Created using Stellarium.
Planets at sunset and sunrise of a single night starting with sunset on the right on September 13, 2017. The night ends on the left with sunrise on the 14th. Click on the image to enlarge. Created using my LookingUp program.
09/12/2017 – Ephemeris – The Moon will hide the bright star Aldebaran after sunrise this morning
Ephemeris for Tuesday, September 12th. The Sun will rise at 7:18. It’ll be up for 12 hours and 40 minutes, setting at 7:58. The Moon, 1 day before last quarter, will rise at 12:13 tomorrow morning.
This morning during daylight at around 8:40*. the bright star Aldebaran will disappear behind the Moon. Binoculars or a small telescope can be used to spot Aldebaran, the bright star in the constellation Taurus the bull’s eye. Taurus and the rest of the winter constellations are visible before sunrise. The sky needs to be absolutely clear to be able to spot the event. The star will be seen to approach the bright side of the Moon. The star will reappear around 9:53 a.m.* on the dark western edge of the Moon. These events are called occultations. They come from the word occult, which means hidden. In actuality the solar eclipse of three weeks ago was a spacial case of an occultation for those in the path of totality.
The times given are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
* The disappearance and appearance times for Aldebaran are within a couple of minutes for Western Michigan. For other locations in the occultation path Stellarium will give pretty good times for the events by modeling the occultation as I did below. Like a solar eclipse where you are determines the timing of the event.
Addendum
Map of where the occultation is visible. For the area bounded in red, the occultation is visible in the daytime. Credit: Occult4 by IOTA.
Position of the Moon in the sky near the start of the occultation, 8:35 a.m. September 12, 2017. Created using Stellarium.
Aldebaran and the Moon at 8:35 a.m. September 12, 2017. Created using Stellarium.
Aldebaran reappearing from behind the Moon at 9:53 a.m. September 12, 2017. Created using Stellarium.
