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02/12/2018 – Ephemeris – The Winter Circle

February 12, 2018 Comments off

Ephemeris for Monday, February 12th. The Sun will rise at 7:47. It’ll be up for 10 hours and 19 minutes, setting at 6:07. The Moon, 3 days before new, will rise at 6:29 tomorrow morning.

The winter skies are blessed with more first magnitude stars than any other season. Six of these stars lie in a large circle centered on the seventh, It’s called the Winter Circle. This circle is up at 9 p.m. Starting high overhead is yellow Capella in Auriga the charioteer. Moving down clockwise is orange Aldebaran in the face of Taurus the Bull. Then down to Orion’s knee we find blue-white Rigel. Down and left is the brightest star of all the brilliant white Sirius the Dog Star in Canis Major, lowest of these stars in the south-southeast. Moving up and left is white Procyon in Canis Minor, Above Procyon is Pollux in Gemini the twins. All these are centered, well not quite, on Betelgeuse the bright red star in Orion’s shoulder.

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

Addendum

Winter Circle

The bright stars of winter arrayed in a circle (well almost). Created using Stellarium.

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02/08/2018 – Ephemeris – The wonderfully named stars of Orion

February 8, 2018 Comments off

Ephemeris for Thursday, February 8th. The Sun will rise at 7:53. It’ll be up for 10 hours and 8 minutes, setting at 6:01. The Moon, 1 day past last quarter, will rise at 3:09 tomorrow morning.

The constellation of Orion the hunter is visible in the south at 9 p.m. The stars of Orion are interesting in themselves. Starting at the top left of the seven bright stars of Orion’s torso is Betelgeuse the bright red star, whose name means something like “Armpit of the Giant”. The star in Orion’s other shoulder is Bellatrix the “Amazon Star”. Below are the three stars of Orion’s belt, from left to right; Alnitak, Alnilam and Mintaka. Their names mean “Girdle”, “Belt of Pearls”, and “Belt” respectively. Down to Orion’s knees we look on the left to the star Saiph pronounced ‘safe’ which means “Sword”, though it is some ways from the stars of Orion’s sword. Finally there’s the bright blue-white star Rigel whose name means “Left Leg of the Giant”.

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

Addendum

Orion with star names.

The named stars of Orion. Created using Stellarium.

Betelgeuse, pronounced Beetlejuice is the name of a 1988 movie, where Betelgeuse (spelled properly) is a particularly mischievous demon.  Don’t say his name three times, or he’ll come and ‘help’ you.  Oops, I did.  It is a red giant star near the end of its life.

Bellatrix, is now known to most of us now as the first name as the first name of Bellatrix Lestrange from J. K. Rowling’s Harry Potter book and movie series.  Other members of the Black family have astronomical names, such as Regulus (Leo) Black, and Sirius (Canis Major) Black.

The names of the belt stars were taught to me by Evelyn Grebel of the Grand Rapids Public Museum in the late 1950s.  She was one of the founders of the Grand Rapids Amateur Astronomical Association.  The names Alnitak, Alnilam and Mintaka have stuck with me ever since.  It was through her that I was able to worm my way into working at the museum’s new then unnamed planetarium.  I also remember being in her office with her, listening to the radio as Alan Shepard made his historic suborbital flight on May 5th, 1961.

Rigel is a hot blue-white star, and will probably become a red giant star like Betelgeuse.  There is another bright star named Rigel, but most don’t know it.  It’s Rigel Kentaurus, the leg of the centaur of Centaurus.  It’s better known as Alpha Centauri, a catalog designation, and the nearest star to the solar system.

02/06/2018 – Ephemeris – Monoceros the Unicorn

February 6, 2018 1 comment

Ephemeris for Tuesday, February 6th. The Sun will rise at 7:55. It’ll be up for 10 hours and 2 minutes, setting at 5:58. The Moon, 1 day before last quarter, will rise at 1:09 tomorrow morning.

Among all the constellations in the sky of animals real and mythical, there is also a unicorn. It’s called Monoceros, and inhabits the southeastern sky at 9 p.m. bounded by Orion on the right, Canis Major, the great dog below and Canis Minor, the little dog to the left. Unfortunately for observers without optical aid Monoceros, though large, is devoid of any but the faintest stars. Maybe that’s why no one sees unicorns anymore. It has many faint stars because the Milky Way runs through it. To the telescope it is a feast of faint nebulae or clouds of gas and dust, the birth place of stars, including the red rose of the Rosette Nebula, and the strange and tiny Hubble’s Variable Nebula. It also contains beautiful telescopic triple star system, Beta (β) Monocerotis.

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

Addendum

Monoceros

Monoceros finder chart animation. Created using Stellarium and GIMP.

Rosette Nebula

Rosette Nebula in the infrared from the Spitzer Space Telescope. Credit: NASA/JPL/Caltech

Hubble's Variable Nebula

Hubble’s Variable Nebula photographed appropriately enough by the Hubble Space Telescope. Credit: NASA/ESA and The Hubble Heritage Team (AURA/STScI).

Monoceros DSO finder chart

Looking at some faint objects in Monoceros. NGC 2239 is the star cluster in the center of the Rosette Nebula. The nebula itself is extremely faint. It shows in photographs, but I’ve never seen it visually. The green circle shows Beta Monocerotis, the triple star. All these stars are extremely blue-white hot. Created using Cartes du Ciel (Sky Charts).

Also in the chart above is the semicircular Barnard’s Loop, a supernova remnant a great long exposure photography target.

 

02/05/2018 – Ephemeris – The rabbit that got away

February 5, 2018 1 comment

Ephemeris for Monday, February 5th. The Sun will rise at 7:57. It’ll be up for 10 hours even, setting at 5:57. The Moon, 2 days before last quarter, will rise at 12:06 tomorrow morning.

Orion, the central winter constellation is seen in the south at 9 p.m. He is a hunter, but he’s preoccupied with the charge of Taurus the bull from the upper right. At Orion’s feet, and unnoticed by him is the small constellation of Lepus the hare. It’s very hard to see a rabbit in its dim stars: however, I do see a rabbit’s head ears and shoulders. A misshapen box is the head and face of this critter facing to the left. His ears extend upwards from the upper right star of the box, and the bend forward a bit. Two stars to the right of the box and a bit farther apart hint at the front part of the body. Some see a whole rabbit facing the other way. In Lepus telescopes can find M79, a distant globular star cluster, one of the few in the winter sky.

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

Addendum

Lepus animation

Pick your favorite Lepus outline. Cartes du Ciel, Stellarium, or Hallo Northern SKY (with grid lines).

01/19/2018 – Ephemeris – Orion’s large hunting dog

January 19, 2018 1 comment

Ephemeris for Friday, January 19th. The Sun will rise at 8:14. It’ll be up for 9 hours and 19 minutes, setting at 5:33. The Moon, 3 days past new, will set at 8:15 this evening.

The brightest star-like object in the evening sky is Sirius, also known as the Dog Star. It also is the brightest night-time star in our skies period. Tonight at 9 p.m. it’s located low in the southeastern sky. The Dog Star name comes from its position at the heart of the constellation Canis Major, the great dog of Orion the hunter, which is seen almost like he’s begging, feet to the right. The three stars of Orion’s belt tilt to the southeast and point to Sirius. The name Sirius means ‘Scorcher’, a reference to its great brilliance and twinkling. To me it has a blue tinge like an arc light in a telescope. Its Egyptian name was Sothis, and its appearance in the dawn skies in late June signaled the flooding of the Nile, and the beginning of the Egyptian agricultural year.

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

Addendum

Orion and Canis Major

Orion and Canis Major Animation for 9 p.m. tonight. Created using Stellarium and GIMP.

01/18/2018 – Ephemeris – The spectacular Great Orion Nebula

January 18, 2018 1 comment

This is Bob Moler with Ephemeris for Thursday, January 18th. The Sun will rise at 8:14. It’ll be up for 9 hours and 17 minutes, setting at 5:32. The Moon, 2 days past new, will set at 7:15 this evening.

The constellation Orion the hunter is the south-southeast at 9 p.m. its upright rectangle of four stars frame his belt of three stars in a straight line and still tilt a bit to the left. Below the belt is what appear to the unaided eye as three more stars arranged vertically, his sword. Binoculars aimed at the middle stars of the sword will find a glowing haze around those stars. That is the Great Orion Nebula. It is the birth place of stars, and is even illuminated by a clutch of four hot young stars. One of the discoveries of the Hubble space telescope are what appear, and are tiny cocoons of gas and dust in which stars condense and form. They are called Proplyds, which are short for protoplanetary disks. In each one is the red center, a young star just beginning to shine.

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

Addendum

The lower part of Orion with the Great Orion Nebula. Created using Stellarium.

The lower part of Orion with the Great Orion Nebula. Created using Stellarium.

The Great Orion Nebula (M42) long exposure photograph

The Great Orion Nebula (M42) long exposure photograph by Scott Anttila. Includes all the sword stars.

A new video just posted by NASA

01/16/2018 – Ephemeris – More thoughts about Orion and the Wintermaker

January 16, 2018 1 comment

Ephemeris for Tuesday, January 16th. The Sun will rise at 8:15. It’ll be up for 9 hours and 13 minutes, setting at 5:29. The Moon is new today, and won’t be visible.

We come back to the central constellation of the winter sky Orion the hunter, now in the southeast at 9 p.m. with his three stars of his belt in a straight line, with his upper shoulder stars above and knees below. In one Greek story he was killed by the sting of a scorpion so the gods made sure the rising of the constellation Scorpius would chase him out of the sky to the west. To the Greeks he was a hapless hero. Orion is mentioned in the Bible in the book of Job. The name for Orion in Hebrew is Kesil, meaning “Fool”. To the native peoples around the Great Lakes, the stars here are those of the Wintermaker, who stretches his arms from Aldebaran in Taurus to Procyon in Canis Minor. When he is in the evening sky it is indeed winter.

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

Addendum

As the scorpion approaches Orion makes a hasty exit

When the scorpion (Scorpius) crawls over the southeastern horizon, Orion takes a powder to the west. This is about 5 a.m. in mid January. Created using Stellarium.

Orion-Wintermaker finder animation

Orion-Wintermaker finder animation for 9 p.m., January 16. Created using Stellarium and GIMP.