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Ephemeris: 08/16/2024 – WIMPs and MACHOs
This is Ephemeris for Friday, August 16th. Today the Sun will be up for 13 hours and 58 minutes, setting at 8:46, and it will rise tomorrow at 6:48. The Moon, 3 days before full, will set at 3:34 tomorrow morning.
The dark matter that holds the clusters of galaxies together in the universe may be made of weakly interacting massive particles which astronomers have dubbed WIMPs. These particles would be more massive than the particles that ordinary matter is made of, but do not interact with ordinary matter or give off or absorb light. They are detected by the influence of their gravitational force alone. An alternative idea is Massive Compact Halo Objects or MACHOs. These may be made-up of ordinary matter. Since there are many more low mass stars, like red dwarfs, than there are high mass stars, perhaps there’s the creation of planet sized bodies like brown dwarfs. These are planets more massive than Jupiter, but not massive enough to become stars. As such, they should be practicably invisible.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum
For more information on Dark Matter search for it on the internet. One Article I found is here: https://sciencenotes.org/what-is-dark-matter/. They dismiss MACHOs by not mentioning them at all, concentrating on the much more likely WIMPs.
Ephemeris: 08/15/2024 – What’s the matter with dark matter?
This is Bob Moler with Ephemeris for Thursday, August 15th. Today the Sun will be up for 14 hours and 1 minute, setting at 8:47, and it will rise tomorrow at 6:47. The Moon, 3 days past first quarter, will set at 2:23 tomorrow morning.
Over the past century astronomers have come to the realization that we are seeing only about 5% of the mass and energy of the universe. Galaxies in clusters seemed to move too fast to not escape, dissipating the cluster, yet after billions of years they still exist. Also, the stars in galaxies revolve about their centers much faster than expected revealing missing mass. So astronomers have come up with the idea that either there is missing matter that we can’t see, what’s called dark matter or there is something wrong with Newton’s and Einstein’s theories of gravity. Astronomers have come up with up two possible types of dark matter, which they humorously dub WIMPs and MACHOs. More about them tomorrow.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum
Ephemeris: 08/14/2024 – Which of the naked-eye planets can be seen tonight?
This is Ephemeris for Wednesday, 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, 2 days past first quarter, will set at 1:25 tomorrow morning.
Let’s take our weekly look at the whereabouts of the naked-eye planets. Venus might be glimpsed low in the west with Venus lower in the west around 9:15 pm. It will set at 9:40. It is best seen over a very low or lake horizon. Saturn will rise at 9:49 pm, and by 11 pm will be low in the east southeast, pretty much by itself. Saturn may look disappointing in telescopes this year since rings are nearly edge on and appear almost as a line through the planet. Jupiter and Mars will be up in the east by 5:30 am tomorrow, with Mars one moon-width left of the much brighter Jupiter. They were a bit closer this morning with Mars two thirds of a moon-width to the upper left of Jupiter. That giant planet outshines all the bright stars around it. Jupiter will rise at 1:30 am, with Mars a couple of minutes later.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum
Ephemeris: 08/13/2024 – Antares and the Moon
This is Ephemeris for Tuesday, 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, 1 day past first quarter, will set at 12:41 tomorrow morning.
The Moon tonight will have a companion. Just to the left of it will be a star. That star may not look very bright because it is overpowered by moonlight, but it is one of the brightest stars of the sky. It is Antares in Scorpius the scorpion, a red giant star. Every month for the last several years and for the next several years the moon will pass in front of that star. Unfortunately due to the timing and to the path of the Moon it doesn’t happen for any particular spot on the Earth very often. Tonight, as the Moon sets it will be approaching Antares but will appear about to pass below it at the time it sets. We will not be able to see the Moon actually cover or occult Antares from Northern Michigan until May 2028, nearly four years from now.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum
Ephemeris: 08/12/2024 – Expect a stellar explosion soon
This is Ephemeris for Monday, August 12th. Today the Sun will be up for 14 hours and 9 minutes, setting at 8:52, and it will rise tomorrow at 6:43. The Moon, at first quarter today, will set at 12:07 tomorrow morning.
This is a reminder that we are expecting a once in a lifetime nova or exploding star in our skies fairly soon, maybe in a month or two. At least we’re hoping. Unlike many reoccurring events in astronomy this one cannot be predicted exactly since we’re not really sure what is happening. We have a general idea. The star is T Coronae Borealis which is in the Northern Crown constellation, which is a small semicircular stellar group near the star Arcturus which is a bright star found off the end of the handle of the Big Dipper. It is to the upper left of that star and the kite shaped constellation of Boötes of which Arcturus is at the base. The nova will appear as bright as Corona’s brightest star, but will fade in about 8 days below naked eye visibility. So it will be easy to miss.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum
Ephemeris: 08/09/2024 – Star Party tomorrow night!
This is Ephemeris for Friday, August 9th. Today the Sun will be up for 14 hours and 17 minutes, setting at 8:56, and it will rise tomorrow at 6:40. The Moon, 3 days before first quarter, will set at 11:03 this evening.
Tomorrow The Grand Traverse Astronomical Society will be part of the Port Oneida Rural Arts and Culture Fair, an event sponsored by the Sleeping Bear Dunes National Lakeshore. The society will bring their telescopes to the Thoreson Farm on South Thoreson Road off M22 North of Glen Arbor for a Star Party beginning at 9 p.m. South Thoreson Road is a loop off M22. On tap will be the fat waxing crescent Moon and some of the brighter wonders of the summer sky. Even though the moonlit skies will be bright, there are plenty of wonders still visible in the telescopes. We might have a shot at Saturn later in the evening along with a few bright Perseid meteors to wow the viewer. The peak of the Perseid meteor shower will be Monday morning after the Moon sets.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum
Ephemeris: 08/08/2024 – The source of the Perseid Meteor Shower
This is Ephemeris for Thursday, August 8th. Today the Sun will be up for 14 hours and 20 minutes, setting at 8:58, and it will rise tomorrow at 6:38. The Moon, halfway from new to first quarter, will set at 10:47 this evening.
The source of the Perseid meteor shower is Comet Swift-Tuttle, first discovered in 1862 buy Lewis Swift and Horace Parnell Tuttle. The comet was expected back around 1982, but it didn’t show. Its orbit was recalculated and was expected around 1992, when it indeed showed up. The comet has a 130 or so year orbit of the Sun which does vary from appearance to appearance. The comet appears to be in resonance with Jupiter’s orbit of the Sun, going around once in the same time Jupiter goes around the Sun 11 times. Its next appearance in the inner solar system will be in the year 2126, when it is expected to be quite bright then, coming relatively close to the Earth.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum
Ephemeris: 08/07/2024 – Where have the naked eye planets wandered off to?
This is Ephemeris for Wednesday, August 7th. Today the Sun will be up for 14 hours and 23 minutes, setting at 8:59, and it will rise tomorrow at 6:37. The Moon, 3 days past new, will set at 10:31 this evening.
Let’s take our weekly look at the whereabouts of the naked-eye planets. The Moon will be visible as a thin crescent in the west with Venus lower in the west northwest around 9:30 pm. It will set at 9:56 pm in the west-northwest. Venus is best seen over a very low or lake horizon. Saturn will rise at 10:17 pm, and by 11 pm will be low in the east southeast, pretty much by itself. Saturn may look disappointing in telescopes this year since rings are nearly edge on and appear almost as a line through the planet. The other two visible planets are in the morning sky.
By 5:30 tomorrow morning, or an hour before sunrise, Jupiter and Mars will be up in the east, with Mars approaching Jupiter just above and to the right of it. Mars will rise at 1:41 am, and Jupiter at 1:53 am.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum
Ephemeris: 08/06/2024 – Looking toward the Perseid Meteor Shower
This is Ephemeris for Tuesday, 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, 2 days past new, will set at 10:15 this evening.
Next Monday morning we’ll see the peak of the Perseid meteor shower. They’re called the Perseids because they seem to come from the constellation of Perseus the hero which is below the W shaped constellation of Cassiopeia in the northeast in the evenings now. The reason they appear to come from the same direction is that they were shed by a comet whose name is Swift-Tuttle discovered in 1862 it’s been around many times before that, though not recognized as such. The first mention of the Perseids in history comes from the year 36 CE, though they were assuredly visible but unrecognized before that. In the past they’ve been known as the Tears of Saint Lawrence because their peak is near the feast date of that martyr. Perseids can be seen now, though not in peak numbers.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). Times will be different for other locations.
Addendum
Ephemeris: 08/05/2024 – Finding Aquila the Eagle
This is Ephemeris for Monday, 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, 1 day past new, will set at 9:58 this evening.
The bright star Altair is seen halfway up the sky in the southeast at 10:30 this evening. It is one of the stars of the Summer Triangle with Vega above it, and Deneb above and left of it. It is the brightest star in the constellation Aquila the eagle which is seen flying northward through the Milky Way, with Altair at its head. Altair is flanked by two stars one above one below. Its wing tips can be seen below, and to the upper right. His tail is almost lost in the Milky Way seen lower in the east southeast. Here in Aquila is where the great rift, the dark band that splits the Milky Way, is most prominent. The Greeks and Romans seemed to have trouble telling vultures and eagles apart. Another name of the constellation was Vultur Volans.
The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EDT, UT–4 hours). They will be different for other locations.
Addendum
Bob Moler's Ephemeris Blog 