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By Comet C/2011 L4 makes an appearance just after sunset this month.
The comet was initially spotted using the Pan-STARRS telescope on Haleakala on Maui on June 6, 2011. Pan-STARRS stands for Panoramic Survey Telescope and Rapid Response System, a wide-field imaging facility. Follow-up images were taken with the Canada-France-Hawaii Telescope on Mauna Kea, and the discovery was announced by Richard Wainscoat of the University of Hawaii Institute for Astronomy.
The comet will pass within 100 million miles of Earth on March 5; it makes its closest approach to the sun on March 10.
Recent estimates suggest that it may be in the range of second magnitude, or as bright as the stars of the Big Dipper. Viewers in the Southern Hemisphere have spotted it in their telescopes already, and report that there is a visible tail; some viewers below the equator have spotted C/2011 L4 with the naked eye already.
The comet will be low in the west at sunset, which will make it harder to see than if it were overhead. You will also need to deal with the glow of dusk, and the fact that the comet sets shortly after dusk. You can start looking for the comet from March 5 on, and the viewing will be best around March 12. To look for the comet, make sure you have a flat west horizon — no buildings, trees, clouds. Looking over the water is a good approach.
On March 5, look west-southwest with binoculars around 7 p.m. The comet will be about 5 degrees (a little more than two fingers held at arm’s length) above the western horizon, and will set by 7:20 p.m. The comet will be about 12 degrees to the left of Mars and exactly the same distance above the horizon as Mars.
By March 12, the comet will be exactly due west and will be about 10 degrees (your palm held at arm’s length) at 7 p.m. By March 12 the comet will be brighter and will set around 7:45 p.m., when it is almost fully dark. One big plus for viewing the comet on March 12: There is a slender crescent moon just to the right of the comet, and that can be your guide.
On the 13th, the comet will be about 10 degrees under the crescent.
For more information, including a comet-watching event sponsored by IFA at Magic Island on the evening of March 12, visit ifa.hawaii. edu.
Jupiter and Saturn
While it was possible to see all five naked-eye planets in February, it’s down to the gas giants Jupiter and Saturn for March, with a month’s-end shot at catching Mercury before dawn.
Jupiter has been the brightest dot of light in the evening sky for the past few months and continues to fill that role in March. Throughout the month, look for Jupiter high in the west at dusk. In early March the planet sets at 1 a.m. By the end of the month Jupiter sets by 11 p.m. Look for the waxing crescent moon next to Jupiter on the nights of March 16 and 17. In March, Jupiter works its way from the back of Taurus and enters the horns of the bull by the end of the month.
Saturn rises in the east throughout March as Jupiter sets in the west. In early March, Saturn rises at 11 p.m. and is halfway up in the western sky at dawn. At the end of the month, Saturn rises just before 9 p.m. and is about one-third of the way up in the west at dawn.
Throughout the month, Saturn forms a near-right triangle with two bright stars above it, Arcturus and Spica. Spica is about 20 degrees above Saturn (the width of two palms at arm’s length) and to the right of Saturn; Arcturus is about 30 degrees, or three palms, above Saturn to the left. Another way to locate Saturn this month: Look for the famous claw of Scorpius the Scorpion; Saturn is the average-bright dot of light about 20 degrees above the claw.
On the night of March 1-2, the waning gibbous moon is right next to Saturn; moon and planet will be less than 2 degrees apart, or the width of your finger at arm’s length. On March 28-29, Saturn will appear a little farther away from a somewhat fatter waning gibbous moon.
While missing for much of March, Mercury returns to the morning sky for the last 10 days of the month. Around March 29, Mercury rises at 5:30 a.m. in the east and is about 10 degrees above the horizon at daybreak. By the end of March the planet comes up just after 5 a.m., and is again about 10 degrees above the horizon at daybreak.
March Sky Map
Most of the great winter constellations are still visible in the west, including Taurus, Orion, Canis Major, Auriga and the Gemini.
High in the northeast, the Big Dipper is a handy guide to locate both the North Star (by using the pointer stars, the two stars in the cup that don’t have the handle attached) and Arcturus. The handle of the Big Dipper points to Arcturus, which is rising in the east in this map.
Leo the Lion is high in the east in our March sky, and you can also spot the False Cross in the south. The official Southern Cross is up in the south-southeast by midnight in early March and by 10 p.m. at the end of the month.
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Mike Shanahan is director of Education, Exhibits and Planetarium. For more information, go to www.bishopmuseum.org/planetarium/planetarium.html
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