There’s something magical about stargazing on a crisp winter night. When the atmosphere is still and cold and clear, the stars seem to blaze brighter. And in a winter sky ablaze with sparkling stars and conspicuous constellations, Orion the Hunter dominates all.
Orion is easy to find this time of year: Just look in the southeast a little after sunset for a line of three medium-bright stars. That’s Orion’s belt and, once you’ve found it, you can easily pick out the rest of the constellation. Orion reaches its highest point in the southern sky about 9 p.m. during the first part of February, and about 7:30 p.m. during the latter part of the month.
The bright, distinctly orange star to the upper left of Orion’s belt is Betelgeuse, pronounced — more or less — “beetle juice.” Betelgeuse, which represents one of Orion’s shoulders, is about 650 light-years away. It is one of the brightest stars in the sky and is incomprehensibly huge. If Betelgeuse replaced the sun in the center of our solar system, its surface would extend beyond the orbit of Mars.
Think of it this way: If the sun were the size of a grain of salt, the Earth would be an invisible speck about 2 inches away. Betelgeuse would be the size of a cantaloupe.
The star marking Orion’s other shoulder, above and to the right of the belt, is Bellatrix. It is about 240 light-years away and is roughly 4,000 times brighter than the sun. From left to right, the belt stars are Alnitak, Alnilam and Mintaka. If you’ve ever wondered how big a degree is, remember Orion’s belt — the three stars are about 1 degree from one another.
Rigel, the brightest star in Orion, represents the hunter’s left knee (on the right as he faces us). It is around 800 light-years away and has a small, bluish companion star, but you’ll need a telescope to see it. The star representing Orion’s other knee is Saiph. Saiph and Rigel are tens of thousands of times brighter than the sun.
One of the most glorious sights in the sky floats a little below Orion’s belt in the hunter’s fainter sword. The Great Nebula of Orion, also known as M42, appears to the naked eye as a fuzzy star, one of three in the sword. Binoculars reveal a small, faint patch of wispiness, but a telescope shows the nebula as an extended cloud, full of detail.
In most photos, the Orion Nebula looks pink and blue, but through a telescope, it appears grayish white, with a hint of green. Astronomers say the nebula, a gas and dust cloud about 24 light-years across, is an interstellar nursery. Deep within its fan-shaped depths, huge globules of gas condense from the surrounding material, becoming denser and denser, hotter and hotter. Once their cores reach the temperatures and pressures needed to sustain nuclear fusion, voila! a star is born.
Those young, hot stars make the nebula glow.
Even urban skygazers should be able to spot Orion’s belt, shoulders and knees. If you’re observing from a dark location, you’ll also be able to see a fainter, vertical row of stars to the right of Orion. They represent his shield, while an even fainter group of stars to the left and above Orion represent his upraised arm, holding a club.
Orion, one of the oldest constellations, is mentioned by name in the Bible and the Iliad. It was especially important to the ancient Egyptians, who knew Orion as Sahu, an incarnation of Osiris, their god of the underworld.
Some have argued that the three stars of Orion’s belt represent the three major pyramids at Giza, which, like the belt stars, lie almost in a straight line.
Jupiter and Venus are can’t-miss sights in February. As the month begins, Venus, the brighter of the two, shines brilliantly in the southwest, then drifts more to the west as the month progresses. Jupiter, nearly as bright, hangs high in the south-southwestern sky after sunset in early February but drifts closer to Venus throughout the month. They’ll reach their closest approach to one another in March.
Look for a sliver of a crescent moon low in the west after sunset on Wednesday, Feb. 22. The planet Mercury is to the left of the moon. A slightly fatter crescent moon hangs a little above and to the right of Venus in the west on Saturday, Feb. 25, and a little to the right of Jupiter the next evening.
Heres a calendar of events for this month:
- February 3 – Full Moon. The Moon will be directly opposite the Earth from the Sun and will be fully illuminated as seen from Earth. This phase occurs at 23:09 UTC. This full moon was known by early Native American tribes as the Full Snow Moon because the heaviest snows usually fell during this time of the year. Since hunting is difficult, this moon has also been known by some tribes as the Full Hunger Moon.
- February 6 – Jupiter at Opposition. The giant planet will be at its closest approach to Earth and its face will be fully illuminated by the Sun. This is the best time to view and photograph Jupiter and its moons. A medium-sized telescope should be able to show you some of the details in Jupiter’s cloud bands. A good pair of binoculars should allow you to see Jupiter’s four largest moons, appearing as bright dots on either side of the planet.
- February 18 – New Moon. The Moon will be directly between the Earth and the Sun and will not be visible from Earth. This phase occurs at 23:47 UTC. This is the best time of the month to observe faint objects such as galaxies and star clusters because there is no moonlight to interfere.
- February 22 – Conjunction of Venus and Mars. A conjunction of Venus and Mars will be visible on February 22. The two bright planets will be visible within only half a degree of each other in the evening sky. Look for this impressive sight in the west just after sunset.
Here is a handy link to a glossary of astronomical terms – great information for the beginning star-gazer or the seasoned pro. Check it out – http://www.seasky.org/astronomy/astronomy-glossary.html
excerpts from seasky.org and azcentral.org