Ephemeris: 01/19/2024 – Finding the Dog Star

January 19, 2024 Comments off

This is Bob Moler with Ephemeris for Friday, January 19th. Today the Sun will be up for 9 hours and 18 minutes, setting at 5:33, and it will rise tomorrow at 8:13. The Moon, 2 days past first quarter, will set at 3:59 tomorrow morning.

In the evening, the great constellation of Orion the hunter can be seen to slowly move from the south-east to the south. Its large rectangle of bright stars is easily visible, even with a full moon. The three stars in a straight line, his belt, tilt downward to the left to a very bright star merrily twinkling lower in the sky. This star is called Sirius, also known as the Dog Star because it’s in the heart of Orion’s larger hunting dog, Canis Major. It is an arc light white star as seen in binoculars or telescope. It is the brightest star in the night sky, and a neighboring star, just twice the distance of the closest star to the Sun at 8.6 light years. Its name, Sirius, has nothing to do with a dog, but is from the Greek meaning scorching for its brightness and sparkling, due to its intense twinkling.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

Sirius finder
A Sirius finder animation for late January/early February at around 8 pm. Even in bright moonlight the seven bright stars of Orion can be seen. The three stars of Orion’s belt make a great pointer to Sirius. Created using Stellarium, GIMP and LibreOffice Draw (for the arrow).
Categories: Ephemeris Program, Observing, Stars Tags: , ,

Ephemeris: 01/18/2024 – A quick guide to Jupiter for the small telescope

January 18, 2024 Comments off

This is Ephemeris for Thursday, January 18th. Today the Sun will be up for 9 hours and 16 minutes, setting at 5:31, and it will rise tomorrow at 8:14. The Moon, 1 day past first quarter, will set at 2:43 tomorrow morning.

Jupiter is the largest planets and is generally the largest appearing planet in a telescope. Venus appears a bit larger than Jupiter only for about four months when it’s the closest it gets to us. There’s always something going on with Jupiter and its 4 Galilean moons which appear to shuffle back and forth from one side to the other of the planet. Jupiter has cloud bands which run parallel to its equator and to the plane of the moon’s orbits. And it has the Great Red Spot, but that spot is not easily visible in small telescopes. Back in the 1950s it was big and brick red. It is since lost a great deal of its redness and size. The moons can hide behind Jupiter or in its shadow or cross in front of the planet. Tonight Jupiter will appear below and right of the Moon.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

Over this evening (January 18, 2024) Europa and Io will be approaching Jupiter and Io will pass Europa to duck behind Jupiter in occultation just before Jupiter sets for us. Callisto will be moving towards Jupiter also, but slowly. Ganymede will be moving a little bit away, being near the furthest extension of its orbit. Created using Cartes du Ciel (Sky Charts).
Categories: Ephemeris Program, Naked-eye planets, Observing, Planets Tags: ,

Ephemeris: 01/17/2024 – Where have the naked-eye planets wandered off to this week?

January 17, 2024 Comments off

This is Ephemeris for Wednesday, January 17th. Today the Sun will be up for 9 hours and 14 minutes, setting at 5:30, and it will rise tomorrow at 8:15. The Moon, at first quarter today, will set at 1:28 tomorrow morning.

Let’s find out where the naked-eye planets have wandered off to this week. Four of those five planets are now visible. Saturn and Jupiter are the evening planets. Saturn can be seen moving from low in the southwest to setting in the west-southwest at 8:42 pm. Jupiter, left of the Moon tonight will move from high in the south to set in the west-northwest at 2:05 am. Venus, the brilliant morning star, will rise in the east-southeast at 5:58 am, and be a brilliant beacon in the morning, shining in the southeast before the bright morning twilight claims it around 8 am. Mercury will also be visible below and left of Venus, and should be visible by 7:30 am. Mars is below left of Mercury, but really is too dim to be seen.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

Jupiter, Saturn and the Moon around 7 this evening, January 17, 2024. Jupiter appears brighter and bigger than the Moon, but isn’t. The blooming of the image of stellar type objects is to make them look brighter. The Moon though brighter is shown at its actual apparent size. They look much nicer in the real sky. Created using Stellarium.
The moon tonight about 7 pm this evening, January 17, 2024, as it might appear in binoculars or a small telescope, with selected features labeled. Created using Stellarium, LibreOffice Draw, and GIMP.
Venus and Mercury as they might appear about 7:30 tomorrow morning, January 18th 2024, in the growing twilight. Created using Stellarium.
Telescopic Saturn, Jupiter and Venus (north up) as they would be seen in a small telescope, with the same magnification. At 7 pm January 17, 2024, for Saturn and Jupiter, and 7:30 am on the 18th, for Venus. Apparent diameters: Saturn 15.84″, its rings 36.89″; Jupiter 41.57″; and Venus 12.96″, 82.6% illuminated. Mercury appears too small to be shown here, but its apparent diameter is 6.02″ and is 74.2% illuminated. The ” symbol means seconds of arc (1/3600th of a degree). Click or tap on the image to enlarge it. Created using Cartes du Ciel (Sky Charts) and GIMP.
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on January 170, 2024. The night ends on the left with sunrise on the 18th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.

Categories: Ephemeris Program, Naked-eye planets, Observing, Planets Tags: , , , , ,

Ephemeris: 01/16/2024 – Watch Saturn’s rings continue to narrow this year.

January 16, 2024 Comments off

This is Ephemeris for Tuesday, January 16th. Today the Sun will be up for 9 hours and 12 minutes, setting at 5:29, and it will rise tomorrow at 8:15. The Moon, 1 day before first quarter, will set at 12:12 tomorrow morning.

After the Moon, the next targets for the small telescope are the planets. Saturn is getting pretty low in the southwest now so there’s only about another month when it’s really visible in steady skies. Of course Saturn has those beautiful rings which are now getting very thin and by the end of March next year they will be edge on to us and then begin to open up through the rest of 2025. One’s first impression of Saturn is generally that besides the rings it’s really tiny. It averages almost a billion miles from the Earth, and even though it’s the second-largest planet it looks very tiny at that distance. Saturn’s largest moon Titan can be seen near the planet it is the second-largest moon in the solar system.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

This is not a photograph of Saturn. It is an image produced by the program Cartes du Ciel or Sky Charts which is a free app for the PC. The rings are narrowing as Saturn approaches an equinox, which will be, for its northern hemisphere, the autumnal equinox. The rings, which orbit over Saturn’s equator, will go edge on to the Earth on March 23rd next year. The rings are about 150,000 miles in diameter however they are less than 100 feet thick so when they go edge-on to us, they will disappear, and so we will see only the thin shadow of the rings projected on the planet. Later, on May 6th, the Sun will pass through the ring plane, the actual date of the equinox, so they will not be illuminated and cast no shadow on the planet. So even though the rings open up a tiny bit for us, the rings will be dark and only appear as a black line against the planet.
Categories: Ephemeris Program, Observing Tags:

Ephemeris: 01/15/2024 – The Moon is a great first target for that new telescope

January 15, 2024 Comments off

This is Bob Moler with Ephemeris for the Martin Luther King Jr. Holiday, Monday, January 15th. Today the Sun will be up for 9 hours and 11 minutes, setting at 5:27, and it will rise tomorrow at 8:16. The Moon, 2 days before first quarter, will set at 10:55 this evening.

The Moon is a great first target for that Christmas telescope. Over the weekend we began a new lunar month so that the Moon appears as a crescent in the southwestern sky after sunset. The first time I looked at the Moon with the telescope or looked at anything in the sky, actually, I found it very difficult to aim the telescope correctly. The field of view of the telescope is very small compared to what you can see with the naked eye. Always start with the lowest power eyepiece because it gives the widest field of view for finding what you’re looking for. It does take a little practice to learn how to aim a telescope, but the moon is a wonderful object to look at because it’s really big and very bright.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

This may be what the waxing Crescent Moon looks like in a small telescope tonight, January 15th 2024. Select features of the Moon are annotated including several I haven’t mentioned before. There’s the keyhole looking constellation on the edge of Mare Fecunditatis named Gutenberg after the inventor of the printing press and also Franklin after Benjamin Franklin. Created using Stellarium, LibreOffice Draw, and GIMP.
Categories: Ephemeris Program, Observing, Telescopes Tags:

Ephemeris: 01/12/2024 – Mercury is at greatest western elongation from the Sun today

January 12, 2024 Comments off

This is Ephemeris for Friday, January 12th. Today the Sun will be up for 9 hours and 6 minutes, setting at 5:24, and it will rise tomorrow at 8:17. The Moon, 1 day past new, will set at 6:49 this evening.

The planet Mercury is reaching its greatest western elongation or separation west of the Sun today at a 23.5 degrees angle, which is pretty good actually, although the angle above the horizon where we see Mercury at this point in the year is not the best. However, Venus can be used to spot Mercury because Mercury will be to the lower left of Venus. Binoculars are always helpful in spotting Mercury for the first time. From now until about a week from now Mercury will not move very much in relationship to Venus, but it will be getting somewhat brighter as its phase goes from half illuminated to more gibbous towards full. Early in the spring it will be seen in the evening sky, at a little bit better angle above the horizon, although it will be it will not be as far away from the Sun. Created using Stellarium and GIMP.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

Venus, Mercury and Mars at 7:30 this morning
Here we have an image of Venus, Mercury and Mars at 7:30 this morning, the 12th of January 2024 with the atmosphere and the horizon and then showing Mercury’s orbit as seen without the ground or atmosphere getting in the way, showing the complete orbit of Mercury. Note that the Sun does not appear in the center of Mercury’s orbit when we can see the whole thing. Mercury’s orbit is quite elliptical. Mercury is quite far away from the Sun compared to the opposite end of the orbit. We are going to see Mercury at the opposite end of the orbit on March 24th when it is visible in the evening, at it’s greatest eastern elongation. It will appear much closer to the Sun then, at 18.7 degrees which is part of the problem we have in the Northern Hemisphere viewing Mercury compared to folks in the Southern Hemisphere.
Categories: Ephemeris Program, Naked-eye planets, Observing, Planets Tags: ,

Ephemeris: 01/11/2024 – Rigel, the star in Orion’s knee or is it his foot?

January 11, 2024 Comments off

This is Bob Moler with Ephemeris for Thursday, January 11th. Today the Sun will be up for 9 hours and 4 minutes, setting at 5:23, and it will rise tomorrow at 8:18. The Moon is new today, and won’t be visible.

Orion’s second first magnitude star is Rigel in the lower right corner of the constellation this is a blue-white star in contrast to Betelgeuse which is a reddish star. The name Rigel is part of a phrase that means Left foot of Jauzah. Jauzah being the old name of the constellation Orion. It’s where we place Orion’s left knee now. In older drawings of the constellation, Orion has his left foot raised as if charging towards Taurus who’s charging at him. Rigel is about the same mass as Betelgeuse, though it’s nearly twice as far away at nearly 900 light years. Rigel is a quadruple star system. The bright Rigel A itself has what looks like a companion in small telescopes. That companion is actually three stars orbiting each other.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

Here are the brightest stars in Orion
Here are the brightest stars in Orion. The
right-most bright star Is Rigel, a bluish white star, in contrast to Betelgeuse which has a ruddy glow. Here it looks like Betelgeuse and Bellatrix are in Orion’s shoulders and Saiph and Rigel are in his knees, with the belt star halfway in between. The word Rigel, however, means foot, and Saiph means sword. Check out the star chart below. Created using Stellarium.
A section of Uranographia centered on Orion
A section of Uranographia centered on Orion, a star atlas published in 1801 by the German astronomer Johann Elert Bode (1747-1826). These were the last maps showing real figures. Added are labels for some of the bright stars and Taurus. Credit: History of Science Collections, University of Oklahoma Libraries via skytonight.org.
Rigel A & B
Rigel with its companion stars as photographed through a telescope. What looks like one dim companion star is a tight grouping of three stars located 2,200 AU from the bright Rigel A. One AU is the distance between the Sun and the Earth, 93 million miles or 150 million kilometers. No attribution. Source: http://washedoutastronomy.com/content/urban-orion?page=1

Categories: Constellations, Ephemeris Program, Stars Tags: , ,

Ephemeris: 01/10/2024 – Where have the naked-eye planets wandered off to this week?

January 10, 2024 Comments off

This is Ephemeris for Wednesday, January 10th. Today the Sun will be up for 9 hours and 2 minutes, setting at 5:21, and it will rise tomorrow at 8:18. The Moon, 1 day before new, will rise at 8:59 tomorrow morning.

Let’s find out where the naked-eye planets have wandered off to this week. Four of those five planets are now visible. Mars will rise too close to sunrise to be seen, however. Saturn and Jupiter are the evening planets. Saturn can be seen moving from low in the southwest to setting in the west-southwest at 9:06 pm. Jupiter will be moving from high in the south to the west by midnight and will set at 2:31 am. Venus, the brilliant morning star, will rise in the east-southeast at 5:44 am, and be a brilliant beacon in the morning, shining in the southeast before the bright morning twilight claims it around 8 am. Mercury will also be visible below and left of Venus, and should be visible by 7:30 am.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

Jupiter and Saturn as they might appear tonight at 7:00 PM January 10th, 2024. Click on or tap on the image to enlarge it . Created using Stellarium.
Venus and Mercury as they might appear at 7:30 tomorrow morning January 11th, 2024. The bright star to the right of Venus is the reddish star Antares in Scorpius, one of the first of the southern summer stars to appear in the morning sky. Click or tap on the image to enlarge it. Created using Stellarium.
Telescopic Saturn, Jupiter and Venus (north up) as they would be seen in a small telescope, with the same magnification. At 7 pm January 10, 2024, for Saturn and Jupiter, and 7:30 am on the 4th, for Venus. Apparent diameters: Saturn 15.95″, its rings 37.16″; Jupiter 42.56″; and Venus 13.39″, 80.8% illuminated. Mercury appears too small to be shown here, but its apparent diameter is 6.78″ and is 61.2% illuminated. The ” symbol means seconds of arc (1/3600th of a degree). Created using Cartes du Ciel (Sky Charts) and GIMP.
The naked-eye planets and the Moon at sunset and sunrise on a single night, starting with sunset on the right on January 10, 2024. The night ends on the left with sunrise on the 11th. Click or tap on the image to enlarge it. Created using my LookingUp app and GIMP.

Categories: Ephemeris Program, Naked-eye planets, Observing, Planets Tags: , , , ,

Ephemeris: 01/09/2024 – Betelgeuse, Betelgeuse, nope I’m not saying it again

January 9, 2024 Comments off

Jan 9. This is Ephemeris for Tuesday, January 9th. Today the Sun will be up for 9 hours and 1 minute, setting at 5:20, and it will rise tomorrow at 8:18. The Moon, 2 days before new, will rise at 8:04 tomorrow morning.

The constellation Orion has two first magnitude stars, the most famous of these is Betelgeuse. It is a red supergiant star in Orion’s shoulder. Its name actually means Armpit of the Central One. Betelgeuse is about 500 light years away, and it is many hundreds of thousands of times brighter than the Sun, and it’s thought to be almost as big as the orbit of Jupiter. For all its size it’s only about 20 times the mass of the Sun. Some call it a red-hot vacuum. Betelgeuse has been interesting lately, first dimming for a period of time and now somewhat brighter than normal. Astronomers are wondering what’s going on with it. Betelgeuse is a type of star that will end with the supernova explosion. The question is when. Perhaps sometime in the next 100,000 years.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

Orion's named stars
Orion’s named stars. Betelgeuse means “Armpit of the Central One”. Bellatrix means “Female warrior”. The names of the belt stars refer to belt or girdle, Rigel refers to Orion’s foot. Saiph means sword, however Orion’s sword is the line of three stars below the belt stars. In binoculars, there’s more than three stars here. Around the second “star” of the sword is the Great Orion Nebula, barely visible here. Created using Stellarium.
Light Curve Betelgeuse 2017 to 2023
Brightness measurements of Betelgeuse from the AAVSO from 2017 to 2023 showing a big dip around January 2020. Betelgeuse has a normal, approximately 400 day, variability cycle and superimposed on this was the big dip in brightness in January 2020. AAVSO = American Association of Variable Star Observers.
Betelgeuse before and after dimming
This comparison image shows the star Betelgeuse before and after its unprecedented dimming. The observations, taken with the SPHERE instrument on ESO’s Very Large Telescope in January and December 2019, show how much the star has faded and how its apparent shape has changed. Credit: European Southern Observatory (ESO)/M. Montargès et al.
Categories: Ephemeris Program, Observing, Variable Star Tags: ,

Ephemeris: 01/08/2024 – Orion vs Taurus: conflict for the ages

January 8, 2024 Comments off

This is Ephemeris for Monday, January 8th. Today the Sun will be up for 9 hours even, setting at 5:19, and it will rise tomorrow at 8:19. The Moon, 3 days before new, will rise at 6:58 tomorrow morning.

There are several instances in the Greek heavens where constellations appear to interact with one another. This is true with Orion the hunter and Taurus the bull. Taurus, whose face is the letter V of stars with orangish Aldebaran as his angry bloodshot eye is charging down on Orion, who has raised a lion skin shield on one arm and an upraised club in the other, ready to strike. They have been frozen in this pose for millennia. Stars below and right of the letter V of the Bull’s face suggest the front part of his body and his front legs charging at Orion. Orion also has two hunting dogs, Canis Major and Canis Minor. Canis Major with its dazzling star Sirius will rise around 7:30 on a line extended down from Orion’s belt.

The astronomical event times given are for the Traverse City/Interlochen area of Michigan (EST, UT –5 hours). They may be different for your location.

Addendum

Orion-Taurus Tableau
Taurus the bull charging toward Orion, who raises a lion skin shield and an upraised club to defend himself, while his two hunting dogs look on. The position of these constellations is at approximately 8 pm. Created using Stellarium.
Categories: Constellations, Ephemeris Program, Mythology, Observing, Uncategorized Tags: , , , ,