A Sky Full Of Pets, Both Real And Imaginary

Spectacular lightning threads the black cloud of smoke and ash from Mount Shinmoedake in Japan late last week. Click on photo to see more pictures. Credit: AP/Takaharu Town Office, Shuji Uchimura

What a magnificent juxtaposition of earthly tumult and starry firmament! Mount Shinmoedake  is located in Kyushu, Japan’s southernmost main island. After some 300 years of quiet, the volcano came back to life last week with powerful explosions and eruptions of lava and ash.

Do you recognize any of the stars in the picture? Just above the glowing orange caldera, you can see the three stars in Orion’s Belt. At upper right is Betelgeuse. Scientists still don’t know the exact origin of lightning in volcanoes, but it probably has to do with collisions between the fast-moving particles expelled by the blasts. The particles hit and break into pieces, some of which are positively charged and some negative. When the difference in the charges becomes extreme, air resistance can’t stop the negatives and positives from reconnecting in a flash of electricity we see as lightning.

Canis Major and Canis Minor are easy to see because each contains a bright star to guide you to the others. Monoceros is a challenge, because its brightest star is 4th magnitude, about the naked-eye limit from suburban areas. The map shows the sky looking south around 9 o'clock. Maps created with Stellarium

Orion is our starting point to find the next cluster of winter constellations – Canis Major the Greater Dog, Canis Minor the Lesser Dog and Monoceros (mon-OSS-ir-us) the Unicorn. All three are ideally placed for viewing during evening hours in February.

Sirius and its tiny white dwarf star companion photographed by the Hubble Space Telescope. Credit: NASA/ESA

An imaginary arrow shot through Orion’s Belt toward the southern horizon takes you directly to the sky’s brightest star, Sirius. Don’t be surprised if you see it twinkling like crazy. Its low altitude as seen from the much of the U.S. and Canada means it’s subject to more atmospheric turbulence, the cause of twinkling. Not only that, but a bright star makes turbulence easier to detect with the eye than a faint star at a similar altitude.

From Sirius, move left (east) and north to find the head of Canis Major, which is angled upward toward Orion. Drop below Sirius, nicknamed the Dog Star, and you’ll find a triangle of brighter stars near the horizon – these represent the dog’s hind legs and tail. The pattern of Canis Major is dog-like enough to my eye, that I can easily picture the animal on his hind legs begging for a treat from Orion.

Two fists above Sirius and forming a nearly equilateral triangle with Betelgeuse in Orion is Procyon, the brightest star in the appropriately small constellation of the Lesser Dog. With only two stars to its name, you won’t have any problem seeing this pup.

Orion is joined by his hunting dog Canis Major, the Little Dog and a unicorn in this mythological depiction of the constellations.

The Unicorn is another matter altogether. Although the imaginary beast takes up a big chunk of sky, its brightest stars are 4th magnitude or two levels fainter than the stars in Orion’s Belt. I’d bet a hundred bucks that the majority of amateur astronomers have never taken the time to find its outline among the many faint stars in the area. Appropriate in a way, since I don’t think anyone’s ever seen a real unicorn anyway.

The beauty of triple star Beta Monocerotis awaits those with small and medium-sized telescopes. The stars are 690 light years away. Each shines between 1300 to 3200 times brighter than the sun. Credit: F. Ringwald, California State University, Fresno

Don’t let the animal’s meek presence turn you away. Within its confines are numerous star clusters and nebulae and one of the sky’s finest triple stars, Beta Monocerotis. As a teenager I somehow passed this star over. Later, as an adult, I finally turned my telescope its way and was stunned by the beauty of three perfectly white, radiant stars shimmering so close together. No other multiple star in the sky has the same effect on me.

A low power view through the telescope might show only two stars – the top one, called A, and the one below it to the left named B. A and B are 7.4 seconds apart, but B and C are only 2.8 seconds. Crank up the magnification to 100x to see all three in their glory. B and C orbit one another and A orbits them in turn. Any inhabitants on potential planets in the system would likely revolve the closer pair or A. Either way, keeping track of all those sunrises and sunsets would require a very thick almanac.

There are many more sights in today’s constellation cluster visible with the naked eye, binoculars and small telescopes. We’ll check them out in the coming nights as we plow our way through the last serious month of winter.

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