What's In The Sky - February 2020

Clear February nights present some great stargazing opportunities. Be sure to bundle up and keep warm while you get outside for some stargazing fun!

Here are a few of Orion Telescopes and Binoculars' top picks for February stargazing:

New Moon

February 23rd should be one of the best nights for deep-sky viewing as the New Moon phase will provide the darkest night of the short month. Use Orion Broadband Filters to enhance your view.

On the evening of Monday, February 9th, Mercury (orbit is shown as a red curve) will reach its widest separation, 18 degrees east of the sun. With Mercury sitting above a nearly vertical evening ecliptic, this will be the best appearance of the planet in 2020 for Northern Hemisphere observers. The optimal viewing times fall between 6 and 7 p.m. local time. Viewed in a telescope (inset), the planet will exhibit a waning half-illuminated phase. Image credit: Starry Night.

Mercury High In The Sky

On February 9th, Mercury will be at its greatest eastern elongation, meaning it is at its greatest separation from the Sun. Mercury will be at an altitude of approximately 16 degrees when the Sunsets at 17:34 PST, making it an ideal time to observe this tricky target.

Planetary Lineup Get up early on President's Day, February 17th, to see a lineup of three planets and the Moon. At dawn, the crescent Moon and Mars, Jupiter, and Saturn will form a line spanning about 39 degrees in the southeastern sky.

Before sunrise on the next day, February 18th, viewers in North America can watch the Moon occult Mars! Better yet, try snapping a sequence of high-magnification pics of the event.

Betelgeuse In The News

Betelgeuse has been in the news lately since dimming down to a magnitude of around 1.5, the lowest brightness in more than a century. The red supergiant is normally variable, but the unusual dimming has brought up the question of whether a supernova is imminent. Betelgeuse is close enough that if it went supernova it would be brighter than the full moon, a spectacular astronomical event. However, the consensus is that this probably won't be happening soon. The best estimate is sometime in the next 100,000 years, so it is more likely that this variability is normal, and we've still got a few millennia before the light show.

It may not be as flashy, but if you want to see a supernova now astronomer Koichi Itagaki discovered a supernova on January 12th. Located in the galaxy NGC 4636 in the constellation Virgo, it should be visible with a 6" or larger telescope. Referred to as SN2020ue, it is currently at magnitude 12.1 and should be visible under dark skies at around 60-100x magnification as a dim star just outside of the galaxy's core.

Galaxies M81 and M82 in Ursa Major - 5 x 300 Second LRGB Image by Insight Observatory.

Bright Galaxies

In late February, bright galaxies M81 and M82 will be about as high in the sky as they will get for North American stargazers. From a dark sky site, these galaxies are visible with a 50mm or larger binocular, but we suggest you use a large telescope to chase these galaxies down just off the leading edge of the Big Dipper asterism. Many observers consider M81 & M82 the best pairing of visual galaxies in the sky!

If you would like to receive image data of galaxies such as M81 and M82 and other deep-sky objects taken on the Astronomical Telescopes for Educational Outreach (ATEO), please visit Insight Observatory's Custom Image Data Request form.

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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Goodbye Betelgeuse?

About five nights ago, I stepped outside, to take a look. That is, up. It's a habit, formed, long ago as a young, budding astronomer (and, 'Rock Star' Drummer...well, never mind about the 'rock-star' drummer part), but - any time that the night sky is clear of clouds - and I know about it - I do a "status" check; just, making sure that, "everything's there - and, things are the way they're supposed to be". Kind of like looking in on your kids, long after they've gone to bed...

While I'm out there, I do a sub-conscious, magnitude comparison, between the stars of the constellation, 'Orion' - a relative, close, loosely-grouped gathering of red and blue, 'super-giant' stars, out here at our 'end' of the galaxy. Throughout my entire life - the stars, "Betelguese", and "Rigel"; the 'right shoulder', and 'left foot', respectively; of the Hunter, Orion - have always appeared to be close in brightness, with the blue, Rigel, out-shining the red, and somewhat variable, Betelguese - by just a few "points". Every night. Every year. Always the same - my whole, life-long, life...

...but on the night of 21 DEC 2019 - something was, very, very different. Indeed -- things were NOT, the way, they were supposed to be.

Betelgeuse is generally the eleventh-brightest star in the night sky and the second-brightest in the constellation of Orion. Image by Muir Evenden on Insight Observatory's 16" f/3.7 astrograph reflector (ATEO-1).

The 'ancient's', had understood the stars to be, 'immovable', 'invariable', and 'eternal' objects. No one could blame them; the distances to the stars - any star, even the very closest - is an unfathomable number of miles away from 'us'. (24,900,000,000,000 - to be exact). Any motion through 3-dimensional space goes undetected; although the stars, *are* moving through space, in their long trip around the galactic core of the Milky Way galaxy (that's ours), they are so distant that their motion is not perceptible to us, here on Earth - and, not to the ancient's, either. Compared with the rest of the universe - we just live at a 'fleeting' pace, but the truth is - the stars do move. And change; sometimes, catastrophically.

The stars of the Orion group are, in fact, a relatively, loosely-grouped, 'open cluster', in which, the grouping is moving through space, together, as a whole, around the galaxy. The group is between, about, 500 to 900 light-years (LY) distant. That's pretty close, by cosmological standards, and accounts for their relative brightnesses, being so high, compared with most other stars. These blue-white beauties are some of the brightest stars that can be seen from Earth - just a bit dimmer, than the brightest star, 'Sirius', which happens to lie very nearby. In fact, if you walk outside, on any, clear, winter night - the brightest stars that you will see will be those of the Orion group.

Astronomers have learned much about the 'Orion group', also known as the 'Orion OB-1 Association', over the decades. They are, distinctly, set apart from the other stars in our, somewhat, limited field of view, in that, quite a few of them are extremely large, bright stars, of a type of star, called a 'super-giant'.

Well, 'So what!?'

OK, well - *here's*, "what": beginning with a 3-star asterism that most people are acquainted with - "Orion's Belt", those three stars are part of the Orion OB-1 Association. The left-most star in the belt, 'Alnitak', is a blue type, supergiant, at 800 LY distant - Alnitak shines in at a monstrous - 100,000 times - brighter than the sun! That's because it is 40 times the diameter of the sun!

The next star, the 'center' star of Orion's 'belt', 'Alnilam', another, blue supergiant, is 375,000 times as bright as the sun. That's because it is 84 times the sun's diameter. The last, or 'right-most' star in the belt, 'Mintaka', is 36 times the diameter of the sun, and blares in at 90,000 times the output of the sun. Another blue supergiant.

The constellation Orion the Hunter - Illustration Credit: Earth Sky and The Atacama Large Millimeter/submillimeter Array (ALMA) captured this image of Betelgeuse, revealing its lopsided shape and a huge bright spot. ALMA (ESO / NAOJ / NRAO) / E. O’Gorman / P. Kervella

Most of the stars that you see, up there, in the dusky grey (it is not black anymore, where I live), are older, dimmer, and somewhat redder stars than these 'Mavericks' of Orion. Supergiant stars are stars that are on their way out. They have near the end of their time on the main sequence, drifting toward oblivion, but, one star out of this group, has aged much faster than the others. And it is, now, visually, very obvious.

The red supergiant, "Betelguese", is now, about ten times, less bright than I remember it as a kid. And it's dimmer, now, than it was, the last time I saw it, just over a year ago. The great, red, supergiant is now at the end of its lifespan. The constellation, "Orion", has changed.

The once, bright, red star, has begun to shrink, inward, toward a collapsing core. Having burned through all of its original hydrogen mass - and its converted, helium mass, it is in the process of fusing its remaining elemental composition, all the way down to iron. Once it has reached this stage, its thermal, expansion energy will no longer counter the energy of gravity, and it will collapse - blowing itself, in a crescendo of blazing light, metals, and x-rays -- to smithereens. It will leave behind, a cold, dead, neutronic core.

Betelguese, is now, ready to do just that.*

*It is difficult to know, exactly, when a star is going to actually go supernova. That could happen, anywhere, from - tonight - to a few more, thousand years. But, it could be - tonight!

Dale Alan Bryant
Senior Contributing Science Writer

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