01/16/2023 – Ephemeris – Orion’s great nebula

This is Bob Moler with Ephemeris for Dr. Martin Luther King Jr. Day, Monday, January 16th. Today the Sun will be up for 9 hours and 13 minutes, setting at 5:29, and it will rise tomorrow at 8:15. The Moon, 2 days past last quarter, will rise at 3:52 tomorrow morning.

The brightest interstellar cloud visible in our skies is the Great Orion Nebula. The word nebula is related to the Latin “nebulum” for cloud. The constellation of Orion is filled with nebulae, most of it are dim or dark. The Great Orion Nebula is in Orion’s sword. The sword is what looks like three stars that look dimmer than the three belt stars hanging from the belt. And there are more than three stars here. Around the stars that appear as the center of the sword stars, to the eye, can be seen a haze in binoculars. A telescope with a wider aperture and low power can see detail in the cloud. With more magnification, a clutch of four baby stars can be spotted in the brightest part of the nebula. They light up the nebula and are called the Trapezium.

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 is lousy with gas and dust. A regular star factory, or nursery. The red nebulae show the predominance of hydrogen in here. In actuality, the Great Orion Nebula vastly outshines all the other nebulae in Orion. The white nebulosity to the right of Rigel is the Witches Head nebula, probably the reflection of Rigel’s light off a dust cloud. Base image by Bernal Andreo, via Wikipedia. Annotations were created by myself.

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

01/24/2022 – Ephemeris – The Great Orion Nebula

This is Ephemeris for Monday, January 24th. Today the Sun will be up for 9 hours and 30 minutes, setting at 5:40, and it will rise tomorrow at 8:09. The Moon, 1 day before last quarter, will rise at 1:03 tomorrow morning.

The closest star nursery to us, places where stars are being born, is the Great Orion Nebula, 1,300 light years away. A light year is about 6 trillion miles, if you want to pace it out. It’s located in the constellation Orion’s sword that hangs below his belt. In as little as a pair of binoculars, it shines by emission and reflection of the light of a tiny clutch of four stars at its heart, which astronomers have called the Trapezium. These extremely hot young massive stars are not destined to live long. Unlike the Sun’s 10 billion year lifetime, these stars lifespans will be measured in millions of years. Yet do not mourn for them, even now stars are forming within their dusty cocoons in the nebula. The Trapezium stars’ deaths will provide heavy elements for new stars and planets.

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

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

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

The inner and brightest part of the Great Orion Nebula. Also, visible are the four stars of the Trapezium, whose ultraviolet emissions light up the nebula. This is pretty much one’s perception of the nebula as seen in a small telescope, except it would appear colorless. In larger telescopes, one would perceive a greenish color. The red color of hydrogen is outside our night adapted visual range. The green emission is due to mainly doubly ionized oxygen and the green emission of hydrogen. Image by Scott Anttila.

02/05/2019 – Ephemeris – The Great Orion Nebula

Ephemeris for Tuesday, February 5th. Today the Sun will be up for 9 hours and 59 minutes, setting at 5:56, and it will rise tomorrow at 7:56. The Moon, 1 day past new, will set at 6:47 this evening.

The closest star nursery to us is the Great Orion Nebula, 1,344 light years away give or take 20 light years. A light year is about 6 trillion miles, if you want to pace it out. It’s located in the constellation Orion’s sword that hangs below his belt. In as little as a pair of binoculars it shines by emission and reflection of the light of a clutch of four stars at its heart, that astronomers have called the Trapezium. These extremely hot baby stars are not destined to live long. Unlike the Sun’s 10 billion year life time these stars lifespan will be measured in millions of years. Yet do not mourn for them, Even now stars are forming in their dusty cocoons in the nebula. The Trapezium stars death will provide the material for new stars.

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

The Trapezium stars in the inner part of the Great Orion Nebula. Image by Scott Anttila

02/13/2018 – Ephemeris – Looking out the thin side of the Milky Way’s disk

Ephemeris for Fat Tuesday, February 13th. The Sun will rise at 7:46. It’ll be up for 10 hours and 22 minutes, setting at 6:08. The Moon, 2 days before new, will rise at 7:07 tomorrow morning.

With Orion and the winter stars grabbing our attention in the south, let’s look to the northeast to southeast where the stars are not as many, and with the exception of the Big Dipper and some other stars, not as bright. The inner stars of the Big Dipper are part of a sparse star cluster only about 80 light years away. The reason for the sparseness is that here we are looking out the thin side of the Milky Way’s disk.  It will be our spring sky. To the west is the autumn evening skies. The thick part of the disk runs from the south-southeastern horizon, to just west of the zenith to the northwestern horizon. The reason the Milky Way isn’t as bright as the summer sections, is that we are looking away from the center to the outer spiral arms. We are in a small arm with the Great Orion Nebula.

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

Addendum

The dome of the sky at 9 p.m. February 13, 2018 showing an enhanced Milky Way. Showing also the drop off in stars off that band to the east and west. Click on image to enlarge.  Created using Stellarium.

Our place in the Milky Way. Note that we appear to be in a barred spiral galaxy.  The arms are numbered and named.  3kpc is the 3 kiloparsec arm. 1 parsec = 3.26 light years. The Sun is about 27,000 light years from the center. Credit NASA and Wikimedia Commons, via EarthSky.org

Our galactic neighborhood on the Orion spur or arm. Credit R. Hurt on Wikimedia Commons, via EarthSky.org.

The summer and winter Milky Way viewing directions. During Spring and Autumn, we look out the sides to the universe beyond. Credit: NASA with annotations by Bob King at Universe Today.

 

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

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

A new video just posted by NASA

01/16/2017 – Ephemeris – The bright cloud in Orion, the Great Orion Nebula

Ephemeris for Martin Luther King Day, Monday, January 16th.  The Sun will rise at 8:15.  It’ll be up for 9 hours and 14 minutes, setting at 5:30.  The Moon, 3 days before last quarter, will rise at 10:30 this evening.

The constellation Orion the hunter, which is in the south-southeast at 9 p.m., is the brightest of constellations with 2 first magnitude stars and 5 second magnitude stars in its torso.  Orion’s most famous feature is the Great Orion Nebula which lies in and around the stars of his sword.  It is bright, and lies about 1,344 light years away. By the way, the word nebula is Latin and means cloud or haze.  The plural of nebula is nebulae.  It can be seen with binoculars as a haze around what to the naked eye looks like the center of the three stars of Orion’s sword.  It is the lit end of a large dark cloud where stars are being formed.  It is illuminated by a clutch of four young stars in a tiny group called the Trapezium.

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

Addendum

Orion with two nebulae.  The Great Orion Nebula is M42.  M78 is another small nebula.  Created using Stellarium.

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

Inner part of the Great Orion Nebula with the four stars of the Trapezium. Image by Scott Anttila.

02/04/2016 – Ephemeris – Orion is visible from everywhere

Ephemeris for Thursday, February 4th.  The Sun will rise at 7:58.  It’ll be up for 9 hours and 56 minutes, setting at 5:55.   The Moon, half way from last quarter to new, will rise at 5:21 tomorrow morning.

The constellation of Orion the hunter is now due south at 9 p.m. It is an upright rectangle of bright stars, the shoulders and knees of this giant.  In the center are three stars in a straight line, his belt, and from his belt hangs a sword.  Orion is the most famous of all constellations world-wide, due to its bright stars, and straddles the celestial equator, so that it is visible at least in part from pole to pole.  It contains the closest star forming region to us, the Great Orion Nebula seen easily in his sword with binoculars or small telescope.  The Horse Head Nebula is found below the left belt star, but only in photographs.  Another photographic feature is Barnard’s Loop, the partial shell of an ancient supernova to the left of Orion.

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

Addendum

Orion from mid latitudes north of the equator. Orion would be upside down if viewed south of the equator. Created using Stellarium.

Orion from near the north pole. Created using Stellarium.

Orion from near the south pole. Created using Stellarium.

The nebulae in Orion including the Great Orion Nebula in the sword, the Horse Head Nebula below the leftmost star of Orion’s Belt named Alnitak. Barnard’s loop is the big arc on the left. Just above Alnitak is the Flame Nebula, I neglected to mention it in the program. It can be spotted in a telescope, especially if Alnitak is moved off the edge of the field of view. Credit Rogelio Bernal Andreo, via Wikipedia.

Note the nebula at the lower right.  It’s the Witch’s Head Nebula, which I believe is shown brighter than it actually is.  It’s being illuminated by the blue giant star Rigel to the left of it.

 

03/10/2015 – Ephemeris – The Great Orion Nebula

Ephemeris for Tuesday, March 10th.  The Sun will rise at 8:04.  It’ll be up for 11 hours and 37 minutes, setting at 7:42.   The Moon, 3 days before last quarter, will rise at 12:43 tomorrow morning.

The constellation of Orion the hunter, now in the south at 9 p.m., contains the most beautiful star forming region in the northern sky.  It is the Great Orion Nebula.  A nebula is simply a cloud.  Back in the early days of telescopes it was anything that appeared fuzzy.  Today it’s any cloud, whether of gas or dust, light or dark.  The Great Orion Nebula is made up of gas, which is ionized and shines by fluorescence by the ultraviolet light of a clutch of four stars in its heart called the Trapezium.  The nebula can be glimpsed with binoculars surrounding what looks like the center star of the vertical line of three stars that appears as the sword hanging from Orion’s belt.  It’s the bright end of a large dark cloud that’s behind the bright stars of Orion.

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

Addendum

Orion upright and due south. Created using Stellarium.

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

Inner part of the Great Orion Nebula with the Trapezium. Image by Scott Anttila

Great Orion Nebula by Scott Anttila

02/21/2014 – Ephemeris – Some nebulae in Orion

Ephemeris for Friday, February 21st.  The sun will rise at 7:33.  It’ll be up for 10 hours and 46 minutes, setting at 6:19.   The moon, 1 day before last quarter, will rise at 1:31 tomorrow morning.

With the moon out of the sky, it’s a good time to get those binoculars or small telescope out to view at least one nebula in the constellation Orion the hunter and maybe even more.  Orion is in the south with those belt stars lie in a straight line.  Below the belt are three fainter stars, vertically arranged: Orion’s sword.  In binoculars each of those stars are multiples.  Around what looks like a center star there is a haze, which is the Great Orion Nebula, the nearest star forming region to us at around 1,400 light years away.  Some of its gasses envelop the stars that make up the top star of the sword.  Orion hosts the famous Horse head Nebula, which unfortunately can only be seen in photographs, It is right below the left star of the belt.

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

Addendum

Orion’s Nebulae in the southern part of the constellation as displayed by Stellarium.

A couple of nebulae are seen here that are not in the text above.  M78 is a small nebula north of the belt star Alnitak.  It is visible in a telescope. The Witch Head Nebula, another large nebula, shining by the reflected light of Rigel.  It’s officially in the neighboring constellation of Eridanus, and I believe strictly a photographic nebula.  The witch head is best seen if the image is turned upside down.

01/08/2013 – Ephemeris – The Great Orion Nebula

Ephemeris for Tuesday, January 8th.  The sun will rise at 8:18.  It’ll be up for 9 hours and 1 minute, setting at 5:20.   The moon, 3 days before new, will rise at 5:56 tomorrow morning.

The closest star firming region to us is the Great Orion Nebula. It’s 1,344 light years  away give or take 20 light years.  A light year is about 6 trillion miles, if you’re counting. It’s located in the constellation Orion’s sword that hangs below his belt.  It shines by emission and reflection of the light of a clutch of four stars at its heart, astronomers have called the Trapezium.  Binoculars can be used to spot the nebula surrounding what looks like the middle star of the sword.  The sword stars aren’t single stars like the belt but groups of stars.  Anyway a telescope, using its lowest power will see a glow around those Trapezium stars.  The glow will have a dark notch out of it, which is a dark cloud in front if it.  Wisps of gas may also be seen.

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

Addendum

The Great Orion Nebula is also number 42 on Charles Messier’s list of objects to avoid when searching for comets.  Amateur astronomers know it as M42, the show piece of the winter sky.

Orion via Stellarium.org

Inner part of the Great Orion Nebula (M42). Image by Scott Anttila.

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