8/12/2023 0 Comments Autumn sky map algol![]() ![]() The result is that Algol’s brightness varies by 1.2 magnitudes every 2.86736 days, or 68 hours 48 minutes 59.9 seconds. As they orbit, each star cuts off the light from the other for a short period. (Image credit: Starry Night software)Īlgol is what is called an "eclipsing variable." It consists of two stars orbiting each other at a close distance, less than 6 million miles (9 million kilometers). Its name means "The Ghoul" in Arabic and it has sometimes been called the "demon star." In early illustrations, it is often depicted as the Gorgon's head in Perseus' hand.Īlgol, the second brightest star in Perseus, is an eclipsing variable: two stars orbiting each other and cutting off each other’s light. Our second star, Algol, has been known to be unusual since ancient times. Its distance is poorly known, but appears to be around 300 light years. Besides changing brightness by 8 magnitudes, it also varies in color, appearing reddest when it is at its dimmest. Mira has a period of 332 days, almost a year in length. That is because these long period variables are all red giant stars, pulsating slowly in the late stages of their development. It is separated by only 2 arc minutes from a 9th magnitude star, but is most noticeable because, like most long-period variable stars, it has a deep red color. (Image credit: Starry Night software)Ĭurrently Mira is around 8th magnitude, so you will need binoculars to see it. On Sunday evening at 8 pm, tune in to the Sunday Night Astronomy Show via the Facebook page or YouTube channel of Astronomy by the Bay.Mira, in the constellation Cetus, is the classic long period variable star, slowly pulsing and changing color over a period of nearly a year. For most of the week the zodiacal light might be visible in the east from rural areas. Mercury and Venus are too close to the Sun for observing. Mars is stationary on Sunday, beginning its westward retrograde motion relative to the stars. On Wednesday evening telescope users might see the shadows of two moons on Jupiter’s clouds with the shadow of Ganymede entering at 9:22 and that of Europa exiting at 10:00. Saturn is at its highest and best for observing at 8 pm, followed by Jupiter at 10:30. The Moon is at first quarter and near Saturn on Tuesday, and on Friday it slides below Jupiter. Next Saturday the Sun will rise at 8:05 am and set at 5:59 pm, giving 9 hours, 54 minutes of daylight (8:08 am and 6:06 pm in Saint John). Saturday’s sunrise in Moncton is at 7:55 am and sunset will occur at 6:09 pm, giving 10 hours, 14 minutes of daylight (7:59 am and 6:16 pm in Saint John). A line from the bottom right star of the W to the top right and extended the same distance brings us to open cluster M52. Next, look above Andromeda for the familiar W-shape of Cassiopeia. Look to the left of the line over halfway between Almach and Algol, the second brightest star in Perseus, for the open cluster of stars called M34. The third brightest star of Andromeda is Almach, situated at the end of the string from Mirach. We see M33 face on, which makes it appear dimmer. In the opposite direction from Mirach, and at about the same distance as M31, is fainter M33, the third largest galaxy in our Local Group behind Andromeda and the Milky Way. The second star from Alpheratz along the brighter string is orange Mirach, and moving up two stars across the dimmer string we encounter the large Andromeda Galaxy, M31. The star at the northeast corner of the square is Alpheratz, the brightest star of Andromeda, from which spread two lines of stars. Angling to the left at the eye we come to a star at the horse’s snout, and extending by nearly half that distance is a larger globular cluster, M15. Extending that line by half its distance is where you will find a small blurry patch called M2, a globular cluster that is the second entry in the Messier list of DSOs. The southwest corner of the square is the base of the winged horse’s neck, and moving away from the square by a few stars takes us to the horse’s eye. Let us start by using the Square of Pegasus as a guidepost. This Week’s Sky at a Glance, 2022 October 29 – November 5 ~by Curt Nasonĭeep sky objects (DSOs), composed of star clusters and nebulae, are often called faint fuzzies by amateur astronomers but many are bright enough to be seen with binoculars in a dark sky. ![]()
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