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11/24/2016 – Ephemeris – The little constellation that used to start the seasonal year
Ephemeris for Thanksgiving Day, Thursday, November 24th. The Sun will rise at 7:52. It’ll be up for 9 hours and 14 minutes, setting at 5:06. The Moon, 3 days past last quarter, will rise at 3:54 tomorrow morning.
From antiquity, the first constellation of the Zodiac has been Aries the ram. That’s the constellation the Sun entered on the first day of spring, or the vernal equinox. Well that was a couple of thousand years ago. Currently the vernal equinox point is in western Pisces. This is due to the wobbling of the Earth’s axis called precession. The spinning Earth like and top or gyroscope wobbles when force is applied to it. In this case the Sun and Moon. One wobble takes 26,000 years to complete. Anyway, Aries is a small constellation of four stars in a bent line, below the triangular constellation of Triangulum, which is itself below Andromeda. It’s a bit west or right of the Pleiades or Seven Sisters star cluster.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Aries the ram animated finder chart for 9 p.m. November 24, 2016. Created using Stellarium and GIMP.
The vernal equinox today, where the blue line, the celestial equator and the orange line, the ecliptic or path of the Sun cross. The Sun is where these lines cross on the first day of spring (March 20th around here). Note that the vernal equinox is now in western Pisces. Created using Stellarium.
The vernal equinox back in AD 100, where the blue line, the celestial equator and the orange line, the ecliptic or path of the Sun cross. The Sun is where these lines cross on the first day of spring. Note that the vernal equinox was at the east edge of Pisces. Created using Stellarium.
1122/2016 – Cepheus the king and its one really important star
Ephemeris for Tuesday, November 22nd. The Sun will rise at 7:49. It’ll be up for 9 hours and 18 minutes, setting at 5:08. The Moon, 1 day past last quarter, will rise at 1:56 tomorrow morning. | There’s a faint constellation in the north above Polaris. It’s a nearly upside down church steeple of a constellation called Cepheus the king, and husband of queen Cassiopeia the W shaped constellation right of it. Cepheus’ claim to astronomical fame is that one of its stars, Delta (δ) Cephei, is the archetype for the important Cepheid variable stars. Delta is in a trio of stars at the top corner of the constellation, and the one on the right. In the early 20th century Henrietta Leavitt discovered that Cepheids in the nearby galaxy the Large Magellanic Cloud varied in brightness with a period that was related to their average brightness. This meant that Cepheids could be used as standard candles to measure great distances to other galaxies.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Cepheus animated finder chart for 8 p.m. November 22, 2016. Created using Stellarium and GIMP.
Delta Cephei finder chart. This is the same orientation as the chart above, but created using Cartes du Ciel (Sky Charts). A green line points to Delta (δ) Cephei.
A word about star designations in the chart above. In general only the brightest stars have proper names. And those usually come from antiquity, and most of those are Arabic. Star designations which are Greek lower case letters come from Johann Bayer’s Uranometria star atlas from 1603. He designated the stars by order of brightness. In constellations with a lot of stars he moved to the Latin alphabet after running out of Greek letters. These were, of course, naked eye stars; the atlas being produced a few years before the invention of the telescope. Stars with numbers are Flamsteed designations from John Flamsteed’s 1725 star catalog. He numbered his stars from west to east in a particular constellation, but only those stars that could be seen from Great Britain. A single star can have many catalog designations. For instance the bright star Vega in Lyra the harp is Alpha (α) Lyrae, Bayer designation; 3 Lyrae, Flamsteed designation; HD 172167, Henry Draper catalog; BD +38 3238, Bonner Durchmusterung, a German catalog; HIP 91262, Hipparcos catalog, and so on.
11/21/2016 – Ephemeris – The two fishies of Pisces
Ephemeris for Monday, November 21st. The Sun will rise at 7:48. It’ll be up for 9 hours and 20 minutes, setting at 5:08. The Moon, at last quarter today, will rise at 12:54 tomorrow morning.
High in the south-southeast at 9 p.m. are the four bright stars of the Great Square of Pegasus, the upside down flying horse. Lying along the left and bottom sides of the great square is the constellation of Pisces the fish, one of the 12 constellations of the Zodiac that lie along the path of the sun, moon and planets. Even though the constellation is called the fish, the fish themselves are not represented in the stars. What can be traced in the stars is the rope, that’s tied to their tails, anchored at the extreme southeastern part of the constellation that is seen in the stars. The right or western end of Pisces is the asterism, or informal constellation, of the Circlet. It’s the loop of 5 stars, the rope around the tail of one of the two fish.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
An animation of the constellation of Pisces the fish, showing first the stars, then the constellation outline including those of Pegasus, and Aquarius, then an artist rendering. Created using Stellarium and GIMP.
I don’t care what the artists think, I still think the circlet is a loop around the western fish’s tail.
11/18/2016 – Ephemeris – Aquarius the water spiller
Ephemeris for Friday, November 18th. The Sun will rise at 7:44. It’ll be up for 9 hours and 26 minutes, setting at 5:11. The Moon, 3 days before last quarter, will rise at 9:43 this evening.
One of the constellations of the zodiac is in the south-southwestern sky at 8 in the evening. It’s the constellation of Aquarius the water bearer. The image that is supposed to be depicted in the stars is that of a hapless fellow spilling a stone jar of water across the sky. Aquarius is fairly hard to spot because it is made of faint stars. One part of him, though, is easy to spot. That is the Water Jar, an asterism or informal constellation. It is a distinctive small nearly equilateral triangle of stars with another star in the center. Stars extending to the right from the water jar are he yoke he’s holding the water jar with. The Water jar is just below the top of the head of the upside down Pegasus the flying horse. The water is flowing down a vertical line of stars.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Aquarius the water bearer or rather spiller at 8 p.m. tonight, November 18. Note that Mars is in the next constellation west, Capricornus, and will enter Aquarius about mid-December. Created using Stellarium and GIMP. If you’re using the Firefox browser you can right-click on the image and display the enlarged version.
The triangle of stars with another star in the center is an asterism called the Water Jar, right where the artist drew it.
11/03/2016 – Ephemeris – Capricornus, a very strange goat
Ephemeris for Thursday, November 3rd. The Sun will rise at 8:24. It’ll be up for 10 hours and 3 minutes, setting at 6:28. The Moon, half way from new to first quarter, will set at 9:25 this evening.
The planet Mars is just to the right of the stars of Capricornus, one of the constellations of the zodiac. Astronomers and others who draw the constellations by drawing lines between stars like a dot to dot puzzle have a hard time getting a sea-goat emerge from its stars. The sea-goat has the front part of a goat and the back half like a fishes tail. Kind of like a mergoat, instead of a mermaid. To me, the constellation looks like a large sagging triangle, just above-left of Mars right now. It will take Mars only to mid December to cross Capricornus to enter Aquarius, just east of it. A couple of thousand years ago Capricornus was the location of the winter solstice point in the sky, for which the Tropic of Capricorn was named. That point is now on the Ophiuchus-Sagittarius border.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Animated GIF of Capricornus in the sky. Time 9 p.m. November 3, 2016. Created using Stellarium ans GIMP.
10/31/2016 – Ephemeris – What’s a Halloween sky without the Ghoul Star
Ephemeris for Halloween, Monday, October 31st. The Sun will rise at 8:20. It’ll be up for 10 hours and 12 minutes, setting at 6:32. The Moon, 1 day past new, will set at 7:28 this evening.
Not all the ghosts and goblins out tonight will be children. One is 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 the second brightest star in the constellation Perseus the hero, rising 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. Astronomers finally found out what was wrong with Algol. It does a slow 6 hour wink every 2 days 21 hours because it is two very close stars that eclipse each other in that period. It did so this morning at 5:53 a.m.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
To run an app to calculate times for the minima of Algol click here: http://www.skyandtelescope.com/observing/celestial-objects-to-watch/the-minima-of-algol/ courtesy of Sky and Telescope Magazine.
Perseus with Cassiopeia and Andromeda in the northeast at 8:30 p.m. on Halloween. Created using Stellarium and GIMP.
Animation of an eclipsing binary star like Algol. Credit: Wikimedia Commons h/t Earth and Sky
10/20/2016 – Ephemeris – Perseus: Is it a hero or a chicken?
Ephemeris for Thursday, October 20th. The Sun will rise at 8:05. It’ll be up for 10 hours and 43 minutes, setting at 6:48. The Moon, 2 days before last quarter, will rise at 10:54 this evening.
Positioned below the W shaped constellation of Cassiopeia half way up the sky in the northeast at 9 p.m. is the constellation of Perseus the hero of Greek myth who slew Medusa and rescued and married Andromeda represented in the constellation above and right of him. Rather than a hero the star pattern seems to look like a chicken or perhaps Big Bird. At least, that’s how I see it. In the back of the chicken is its brightest star Mirfak (Mirphak). Binoculars will show a beautiful group of stars near Mirfak just below unaided eye visibility called the Alpha Persei Association. Tomorrow morning will see the peak of the Orionid meteor shower, though all but the brightest meteors will be overwhelmed by waning gibbous Moon.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Perseus with Cassiopeia and Andromeda in the northeast at 9 p.m. October 20, 2016. Created using Stellarium and GIMP.
10/14/2016 – Ephemeris – Super Moon Sunday and a weird comet
Ephemeris for Friday, October 14th. The Sun will rise at 7:57. It’ll be up for 11 hours and 1 minute, setting at 6:59. The Moon, 2 days before full, will set at 7:03 tomorrow morning.
The full moon on Sunday will be the Hunter’s Moon it will also be a super moon, though not quite as super as November’s super moon. I tend to disparage the effect because of the optical illusion that makes the Moon appear larger when near the horizon than when higher up. Besides there’s nothing out there of comparable size to compare it to. Farther out in space, the comet 29P/Schwassmann-Wachmann 1, which is weird among comets in having a nearly circular orbit between Jupiter and Saturn. It can be observed over it’s entire orbit. Normally a comet out that far is pretty much inactive. However every once in a while it produces an outburst, brightening and expelling a cloud of gas and dust. This can occur up to 7 times a year.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
This month’s super Moon will appear to be 33.4 minutes of arc in diameter when it will rise Sunday night at 7:40 p.m. in the Traverse City/Interlochen area. It will be 222,393 miles (357,906 km) away. November’s super Moon will rise November 14 at 5:53 p.m. and appear to be 33.6 minutes of arc in diameter. Note that half a degree is 30 minutes of arc. Last April 2nd’s mini Moon was 29.4 seconds of arc in diameter when it rose. It was 252,262 miles (405,977 km) away. This full Moon will appear 13.6% larger than last April’s full Moon.
10/04/2016 – Ephemeris – Celestial dolphin and Cupid’s arrow
Ephemeris for Tuesday, October 4th. The Sun will rise at 7:45. It’ll be up for 11 hours and 31 minutes, setting at 7:16. The Moon, 4 days past new, will set at 9:28 this evening.
There’s two small constellations I’ve overlooked in the heat of Summer. Located above the southernmost star of the Summer Triangle of three of the brightest stars in the sky, which is nearly overhead at 9 p.m., is the tiny constellation of Delphinus the dolphin, which is seen high in the south. Delphinus’ 6 stars in a small parallelogram with a tail, really does look like a dolphin leaping out of the water. The parallelogram itself has the name Job’s Coffin. The origin of this asterism or informal constellation is unknown. Of the dolphin itself: the ancient Greeks appreciated this aquatic mammal as we do. There’s another tiny constellation to the right of Delphinus, Sagitta the arrow, which represents Cupid’s dart.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
Delphinus and Sagitta seen in an animation showing them without captions, with stick constellations, labeled, and as an artist sees them. Created using Stellarium.
10/03/2016 – Ephemeris – Cassiopeia the celestial queen, and a look at Venus with the Moon
Ephemeris for Monday, October 3rd. The Sun will rise at 7:43. It’ll be up for 11 hours and 34 minutes, setting at 7:18. The Moon, 3 days past new, will set at 8:55 this evening.
The stars of autumn are in the northeastern to southeastern part of the evening sky. Look half way up the sky in the northeast at 9 p.m. and you can find the W shaped constellation of Cassiopeia the queen. Cassiopeia never sets for us in Michigan. It is opposite the pole star Polaris from the Big Dipper. Above Cassiopeia is a dim church steeple shaped constellation of Cepheus the king. The steeple is toppled to the left. The Milky Way flows through Cassiopeia and through a corner of Cepheus to the bright star Deneb in Cygnus the Swan, or Northern Cross, overhead. Below Cassiopeia it flows through the constellation of Perseus the hero, which kind of looks like a chicken, to the bright star Capella near the horizon.
Times are for the Traverse City/Interlochen area of Michigan. They may be different for your location.
Addendum
The crescent Moon will appear above Venus tonight.
Looking very low in the west-southwest at 7:38 p.m., 20 minutes after sunset, October 3, 2016. The thin crescent Moon will appear about 4 degrees 15 minutes (8 1/2 moon diameters) above Venus. Created using Stellarium.
Cassiopeia with Cepheus, Cygnus and Perseus in the Milky Way in the northeastern sky. Created using Stellarium.
Bob Moler's Ephemeris Blog 