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Archive for October, 2018

10/31/2018 – Ephemeris – The bright planets tonight

October 31, 2018 Comments off

Ephemeris for Halloween, Wednesday, October 31st. The Sun will rise at 8:19. It’ll be up for 10 hours and 13 minutes, setting at 6:32. The Moon, at last quarter today, will rise at 1:02 tomorrow morning.

Let’s look at the bright planets for tonight. Three of them are visible in the evening sky. Jupiter will be barely visible very low in the west-southwest after sunset. It will set at 7:30 p.m. Saturn, the ringed planet, will start the evening low in the south-southwestern sky and will set at 9:49 p.m. Mars will be low in the south-southeast as the skies darken tonight. and is now 73.2 million miles (117.9 million km) away. Mars will be due south at 8:39 p.m., and it will set at 1:33a.m. Mars is picking up speed moving eastward, crossing the constellation of Capricornus this month. It’s currently in eastern Capricornus. Venus, now a morning planet, will rise at 7:45 tomorrow morning, 34 minutes after the Sun.

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

Addendum

Evening planets
Evening planets at 8 p.m. October 31, 2018.  Click on image to enlarge.  Created using Stellarium.

Binocular Moon
The waning crescent Moon as it should appear tomorrow morning in binoculars. Created using Stellarium.
Saturn and Mars with the same magnification at 8 p.m. Created using Cartes du Ciel (Sky Charts).
Stars and planets from sunset to sunrise
Planets and the Moon at sunset and sunrise of a single night starting with sunset on the right on October 31, 2018. The night ends on the left with sunrise on November 1st. Click on the image to enlarge. Created using my LookingUp program.

 

Update

I know, the content above isn’t very spooky for Halloween.  However, NASA came to the rescue with their Halloween Special: Universe of Monsters.  Fitting with our theme today, it’s about planets… of the Exo variety.  Click here!

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10/30/2018 – Ephemeris – Algol the spookiest star in the sky

October 30, 2018 Comments off

Ephemeris for Tuesday, October 30th. The Sun will rise at 8:18. It’ll be up for 10 hours and 16 minutes, setting at 6:34. The Moon, 1 day before last quarter, will rise at 11:53 this evening.

Not all the ghosts and goblins out tomorrow night will be children. One will be out every night because it’s a star. Its name is Algol, from the Arabic for Ghoul Star or Demon Star. The Chinese had a name for it that meant “piled up corpses”. It’s normally the second brightest star in the constellation Perseus the hero, visible in the northeast this evening. The star is located where artists have drawn the severed head of Medusa, whom he had slain. Medusa was so ugly that she turned all who gazed upon her to stone. Algol is her still glittering eye. The star got these names before astronomers found out what was wrong with it. They found out that it does a slow wink every two days, 21 hours.  That’s because Algol is two stars that eclipse each other. Her next evening wink will be dimmest at 8:10 p.m. November 13th.

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

Addendum

Algol Finder
Perseus, Cassiopeia, Andromeda with Algol finder animation for Autumn evenings. Created using Stellarium and GIMP
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Eclipsing Binary Star
Animation of an eclipsing binary star like Algol. Credit: Wikimedia Commons h/t Earth and Sky

10/29/2018 – Ephemeris – Perseus the hero

October 29, 2018 Comments off

Ephemeris for Monday, October 29th. The Sun will rise at 8:16. It’ll be up for 10 hours and 18 minutes, setting at 6:35. The Moon, 2 days before last quarter, will rise at 10:48 this evening.

bout a third the way from the east northeastern horizon to the zenith at 9 p.m. and below the letter W shaped constellation of Cassiopeia the queen is Perseus the hero. It’s kind of a odd shape for a hero, To me it looks like the cartoon roadrunner. To those who’s imagination doesn’t run to cartoons, its shape is also like the Greek letter pi. It’s two brightest stars are Mirfak and Algol the demon star. Look at the area around Mirfak with binoculars and you will see a large group of stars just below naked eye visibility. It’s called the Alpha Persei association. That because Mirfak is Alpha Persei. The group is about 560 light years away, which means, though close, are farther away than the Pleiades, below and right of them.

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

Addendum

Perseus and Algol Finder
Perseus, Cassiopeia, Andromeda with Algol finder animation for Autumn evenings. Created using Stellarium and GIMP.

Alpha Persei Association
Alpha Persei Association.  Mirphak or Mirfak is Alpha Persei, Created using Stellarium.

10/26/2018 – Ephemeris – Venus passes inferior conjunction with the Sun today

October 26, 2018 Comments off

Ephemeris for Friday, October 26th. The Sun will rise at 8:12. It’ll be up for 10 hours and 27 minutes, setting at 6:40. The Moon, 2 days past full, will rise at 8:19 this evening.

Later this morning the planet Venus will pass in inferior conjunction with the Sun, moving officially from the evening sky to the morning sky. Inferior conjunctions are when Venus is between the Earth and the Sun. We haven’t seen Venus for over a month, it setting too soon after the Sun to be spotted. It’s appearance in the morning sky will be much more sudden. On fall mornings the ecliptic, the path of the Sun and most planets is more vertical in the sky, opposite that of the evning sky, so that Venus will suddenly appear. Being south of the Sun, it will take 3 days, next Monday morning to rise with the Sun, but after that Venus will rise 8 minutes earlier each morning for a while. It should be easily visible in two weeks as the bright Morning Star

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

Venus near solar conjunction
Venus and the Sun recorded by the Solar & Heliospheric Observatory (SOHO) LASCO C3 coronagraph less than 24 hours before the actual instant of Inferior conjunction. Credit: ESA/NASA.

10/25/2018 – Ephemeris – Europe and Japan launch a joint mission to Mercury

October 25, 2018 Comments off

Ephemeris for Thursday, October 25th. The Sun will rise at 8:11. It’ll be up for 10 hours and 30 minutes, setting at 6:41. The Moon, 1 day past full, will rise at 7:44 this evening.

A joint mission to Mercury by the Europeans and the Japanese called BepiColumbo was launched late Friday night October 19th our time (EDT), 20th (UT). It will take 7 years to be able to drop into orbit of the innermost planet to make only the second spacecraft to do so. To drop into Mercury’s orbit from the Earth’s orbit the spacecraft will need to lose a whole lot of velocity. The trip there will entail one flyby of the Earth, two of Venus, and six of Mercury itself. Planetary flybys have been used since the 1970s to use a planet’s velocity to add to or subtract from a spacecraft’s velocity, depending on how it approaches the planet. If crossing in front of a planet some velocity is subtracted from the spacecraft, allowing it to drop closer to the Sun. If coming up from behind the spacecraft gets to add to its velocity relative to the Sun.

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

Addendum

Orbits
Animation of BepiColombo’s trajectory from 20 October 2018 to 2 November 2025. Earth’s orbit Blue, Cyan Venus, Green Mercury, Purple BepiColumbo.
BepiColumbo
BepiColumbo spacecraft separates into two acitve satellites at Mercury. ESA’s MPO, Mercury Planetary Orbiter; and JAXA’s MMO, Mercury Magnetospheric Orbiter. Credit DLR/ESA

10/24/2018 – Ephemeris – Looking for the bright planets tonight

October 24, 2018 Comments off

Ephemeris for Wednesday, October 24th. The Sun will rise at 8:10. It’ll be up for 10 hours and 33 minutes, setting at 6:43. The Moon, at full today, will rise at 7:13 this evening.

Let’s look at the bright planets for tonight. Three of them are visible in the evening sky. Venus, though still officially an evening planet for two more days sets before the Sun because it is south of the Sun’s path. Jupiter will be very low in the west-southwest after sunset. It will set at 7:53 p.m. Saturn, the ringed planet, will start the evening low in the southwestern sky and will set at 10:14 p.m. Mars will be low in the south as the skies darken tonight. and is now 68.9 million miles (111.0 million km) away. Mars will be due south at 8:51 p.m., and it will set at 1:39 a.m. Mars is picking up speed moving eastward, crossing the constellation of Capricornus this month. It’s currently in eastern Capricornus.

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

Addendum

Evening Planets
Mars and Saturn in the evening with the full moon at 8 p.m. October 24, 2018. Click on image to enlarge. Created using Stellarium.
Binocular Moon
The full Moon as it should appear tonight in binoculars. Created using Stellarium.
Telescopic Planets
Saturn and Mars with the same magnification at 8 p.m. 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 October 24, 2018. The night ends on the left with sunrise on the 25th. Click on the image to enlarge. Created using my LookingUp program.

10/23/2018 – Ephemeris – Uranus is at opposition from the Sun today

October 23, 2018 Comments off

Ephemeris for Tuesday, October 23rd. The Sun will rise at 8:08. It’ll be up for 10 hours and 36 minutes, setting at 6:44. The Moon, 1 day before full, will set at 7:48 tomorrow morning.

Later tonight the planet Uranus will reach opposition from the Sun. This is also about the time it is closest to the Earth at 18.9 Astronomical Units, or 18.9 times the Earth’s distance from the Sun, or 1.8 billion miles away. Uranus now is just barely visible to the naked eye by those with perfect vision at magnitude 5.7. It is fairly easy to spot in binoculars as a blue-green star. There are no blue-green stars. However it is in a rather star poor part of the sky. It is close to the bright Moon tonight, so I’d wait until Sunday night to try to spot it in dark skies. Then Uranus will be in the east at 9 p.m. below and right of the rightmost star of the three brightest stars of the constellation Aries. About half way from that star to the bottom leftmost star of Pisces. Uranus was the first new planet found since antiquity by William Herschel in 1781.

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

Addendum

Wide view of Uranus finder chart
Wide view of Uranus finder chart looking east at 9 p.m. Sunday October 28, 2018. Created using Cartes du Ciel (Sky Charts).
Narrow view of Uranus finder chart
Narrow view of Uranus finder chart looking east at 9 p.m. Sunday October 28, 2018. It shows stars down to 9th magnitude. Created using Cartes du Ciel (Sky Charts).