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Sunday, March 15, 2020

M81 and M82 - "The Odd Couple"

Think of the perfect example of a "well-behaved", spiral galaxy, and M81 comes to mind, as, utter perfection. In the opposite direction, think of a galactic, "wild and crazy guy" - and it's M82. Now think of them, as a pair. Talk about an "Odd Couple"!

We are extremely fortunate to have this pair, as nearby as they are, at roughly, 12 light-years. The two, are members of the Ursa Major galactic cluster - a knot, in the Virgo Super-cluster of galaxies, as is our own, "Local Group", of galaxies.

M81, Bode's Galaxy (left) and M82, The Cigar Galaxy (right) in Ursa Major imaged on ATEO-1, the 16" f/3.7 astrograph reflector. Image data acquired by Muir Evenden and processed by Utkarsh Mishra.
M81, Bode's Galaxy (left) and M82, The Cigar Galaxy (right) in Ursa Major imaged on ATEO-1, the 16" f/3.7 astrograph reflector. Image data acquired by Muir Evenden and processed by Utkarsh Mishra.

M81 and M82, are among the finest targets for the amateur astronomer with, even, a medium-sized telescope (6"-12"), their magnitude's being, approximately, 7th, and 9th, respectively. But they can be detected in smaller scopes, and even, in a good pair of binoculars*, under good sky transparency conditions.

Let's separate the pair out for some analyses:

M81 is a type Sa spiral galaxy. It's, well - perfect. So much so, that it shares the distinctive title of, relatively few galaxies, as a "Grand Design Spiral". Now, that's something to boast about. And I do!

At a diameter of 90,000 light-years, and a distance of 12 million light-years, its relatively large size and brightness, make it a "stunning" find in the eyepiece. In medium-sized scopes (12+"), the uniformity of its, "oh!-so-homogenous" spiral-arm structure, is notable.

And then, there was M82...

Well; if ever a galaxy looked like it was exploding - M82 - is it. In fact, for a very long time, that's just what astronomers thought was happening. However, there's a little more to it: what's really going on there, is, a massive outburst of star formation - to the point, that, in a sense it is "exploding" - with new stars! Our, Milky Way galaxy (BTW: a barred-spiral, or, Sb-type), has a stellar generation rate of about 3, new stars, per year. M81's rate of star-formation is something like, 33 times that, of ours! (Whew!)

Because of the intense gravitational interaction between M81 and M82 - as well as, nearby, Ursa Major group member, NGC3077 - a small, disrupted, elliptical galaxy - both, M82 and NGC3077 are undergoing, intense, star formation periods in a very short span of time, as galaxies go. Tidal, and other, interruptions are causing large volumes of gases between the three galaxies, to fall inward, toward the cores of M82 and NGC3077. (M81 is, seemingly, immune to this sort of thing, of course!) But, all, three galaxies, are enveloped within interactive streams of gases. Both, M81 and M82, have hosted fairly recent supernovae activity; SN1993-J, in 1993 in M81 - and, SN2014-J, in 2014 in M82.

* Some, experienced, advanced amateurs have been able to detect both of these galaxies, under extremely good transparency conditions using only the unaided eye!

Dale Alan Bryant
Senior Contributing Science Writer

24 hours of Luminance, Red, Green, and Blue image data of M81 and M82 are available for download from Insight Observatory's deep-sky image repository, Starbase
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Monday, March 2, 2020

Get Ready For the April Fireballs!

"Meteor"; "meteoroid"; "meteorite"; "falling star"; "fireball"; "shooting star"; "comet"; "asteroid" -- what does it all mean!?

Here is a simple and intuitive answer, provided in this beautiful infographic from the American Meteor Society.

Regarding this terminology: excluding "comet", and "meteor" - all of the others refer to the same type of object, which, is "asteroidal" in nature; that is, composed of rock, metal, or a mixture of both. Their origins are, usually, from comets, as well as from the asteroids within the Asteroid Belt. The Asteroid Belt lies between the orbits of Mars and Jupiter. Comets originate from the Oort Cloud, and from the Kuiper Belt. All are remnant matter left over from the formation of the Solar System.

Meteor Terminology - American Meteor Society - www.amsmeteors.org - Graphic concept and design by Vincent Perlerin and Mike Hankey for AMS - 2013.
Meteor Terminology - American Meteor Society - www.amsmeteors.org - Graphic concept and design by Vincent Perlerin and Mike Hankey for AMS - 2013.

Note that the word, meteor, refers to the "light" emitted from a meteoritic object, and not the meteoritic object, itself, that is producing the light; therefore, a meteor and a falling star, technically, are not the same thing. In other words, a meteor is created by an object called a "meteoroid" (which, of course, can be "asteroidal", or, "cometary" in nature! 😁)

The April Fireballs, are a small collection of asteroidal and cometary debris that orbits the sun in an elliptical path. About the 15th, of every April, some of this material enters Earth's atmosphere, and combusts, in a spectacularly bright meteor called a "fireball".

Dale Alan Bryant
Senior Contributing Science Writer
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Sunday, March 1, 2020

What's In The Sky - March 2020

Take your family on a journey to the stars from the comfort of your own backyard! Here are some of Orion Telescopes and Binoculars top picks for March stargazing:

M42, The Orion Nebula imaged on Insight Observatory's ATEO-3 remote telescope by Jimmy D. from Plymouth South Middle School, Plymouth, Massachusetts.
M42, The Orion Nebula imaged on Insight Observatory's ATEO-3 remote telescope by Jimmy D. from Plymouth South Middle School, Plymouth, Massachusetts.

Orion Continues to Shine

Constellation Orion is still well-placed in March skies for telescopic study. Check out bright nebula M42, also called the Orion Nebula, which is visible as the middle "star" of Orion's "sword" just south of the three recognizable stars of Orion's belt. While easily detected in astronomy binoculars, the wispy Orion Nebula will reveal more intricate details in a telescope. After March, our namesake constellation will get lower and lower in the west, making it harder to see as the Sun moves eastward in the sky.

Brilliant Binocular Clusters

Grab a pair of 50mm or larger astronomy binoculars in March for great views of the Pleiades star cluster (M45), the Beehive cluster (M44), and the must-see Double Cluster in Perseus. These sparkling sky gems are simply beautiful when observed with big binoculars, or use a wide-field eyepiece and short focal length telescope for a closer look.

Galaxies M81 and M82 in Ursa Major imaged on Insight Observatory's ATEO-1 remote telescope and processed by Utkarsh Mishra from almost 5 hours of image data.
Galaxies M81 and M82 in Ursa Major imaged on Insight Observatory's ATEO-1 remote telescope and processed by Utkarsh Mishra from almost 5 hours of image data.


Galaxies Galore

By about 9-10pm throughout March, Ursa Major, Leo, and the western edge of the Virgo galaxy cluster are high enough in the eastern sky to yield great views of some of our favorite galaxies. Check out the bright pair of M81 and M82 just above the Big Dipper asterism. Look east of bright star Regulus to observe the Leo Triplet of galaxies M65, M66, and NGC 3628. In the northeastern sky, check out the famous Whirlpool Galaxy (M51). While the Whirlpool can be seen with modest 50mm binoculars, using a 10" or 12" telescope in a location with dark skies will display the distant galaxy's beautiful spiral arms. With an 8" or larger telescope and a dark sky, this region of the sky harbors dozens of galaxies — try to find them all!

Orion Telescopes and Binoculars 10", 12" and 8" Dobsonian Telescopes are ideal for viewing deep-sky objects such as M42, the Orion Nebula and galaxies M81 and M82 in Ursa Major. Image credits: Orion Telescope and Binoculars.
Orion Telescopes and Binoculars 10", 12" and 8" Dobsonian Telescopes are ideal for viewing deep-sky objects such as M42, the Orion Nebula and galaxies M81 and M82 in Ursa Major. Image credits: Orion Telescope and Binoculars.

Morning Close Approaches

Starting on March 19th and for the next two mornings, Mars and Jupiter will be less than 1 degree apart. At around 60x magnification they should both fit in the field of view of a telescope. The pair rise around 04:30 in the southeastern sky, and for observers near 40 degrees latitude will reach an altitude of approximately 25 degrees by sunrise at 07:00. Saturn isn't too far away either, about 7 degrees away from the pair that morning.

On March 31st Mars continues its trek across the morning sky to meet with Saturn for a close approach of 54 arcminutes as the Sun rises.

All objects described above can easily be seen with the suggested equipment from a dark sky site, a viewing location some distance away from city lights where light pollution and when bright moonlight does not overpower the stars.
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