Aquila, representing an Eagle, is one of the more prominent constellations. Part of this is due to its brightest star Altair (magnitude .76), which is only 16.7 light years away. And part is due to Aquila resting on the celestial equator, which means that except from extreme northern and southern latitudes this constellation is visible high up in the sky when it crosses the meridian, with much less interference from urban lighting. Altair is at the southern vertex of the Summer Triangle, an asterism composed of the first-magnitude stars Altair, Vega and Deneb. The first time I went to the beach with Melissa was during the Memorial Day weekend in 1986, and the two of us stood at the edge of the St. Augustine public pier looking eastward, watching the relentless ocean waves below and waiting for Altair's late night rising, surrounded by people fishing...that was fun. Aquila also has several deep-space objects, most of the brightest being star clusters. When I pick a "constellation of the month", the only condition is that it crosses the meridian at 10 pm Daylight Savings Time...so like last year's August pick Sagittarius, Aquila does just that...but it's very visible for most of the year at some time during the nighttime hours from dusk to dawn...
No comments:
Post a Comment