Greetings, Stargazers.
The center of the Milky Way galaxy is in the direction of the constellation Sagittarius. Just after dark, the galaxy core will be rising in the southeastern sky and be due south around midnight, never being more than 30 degrees above the horizon. This is one of the most rewarding regions in the entire sky. There are numerous targets for your naked eyes, small binoculars or for any size telescope.
The Milky Way is one of many galaxies in a much larger universe, but as recently as 100 years ago that fact was hotly debated. Our galaxy’s shape is a disk with a central bulge. The sun is inside the disk about halfway between the center and the edge, so when we look at the Milky Way, we see this disk edge-on, as a band surrounding us and the brightest part toward the central bulge. Dark dust clouds between us and the center block much of the light, but they also provide visual interest in the same way that some clouds can enhance a sunset.
At the center of the bulge is a black hole with the mass of about 4 million suns. The mass has been figured out using time-lapse photography. Over the last couple of decades, the sequence shows stars orbiting an invisible something that must have a tremendous mass to make them orbit so quickly.
While Sagittarius may be the archer of mythology, it is certainly the “teapot” to 21st century observers. The teapot is an asterism (meaning pattern of stars) that is only part of the larger whole of the constellation. With the teapot pouring toward the west, the Milky Way becomes the steam rising from the spout.
M22, the Sagittarius cluster, is a bright globular cluster about 2 degrees up and to the left of the topmost star in the teapot. There are several other globular clusters visible with telescopes, but none are as bright as M22.
M8, the Lagoon Nebula, is about 5 degrees to the right of that same star. After the Orion Nebula, the Lagoon Nebula is the second brightest star-forming region we can see. You can see the Lagoon with your naked eye. With binoculars, numerous stars are visible as part of the open cluster associated with it. The glowing hydrogen gas that makes M8 so interesting will show up red in photographs, but because of the limitations of our eye sensitivity, we will only see this as a pale blue-gray fuzzy patch.
Slightly to the north of M8 is M20, the Trifid Nebula. Dark dust bands divide this nebula into three, thus its name.
Less than 10 degrees north of the teapot is M17, called either the Omega Nebula, the Swan Nebula or the Checkmark Nebula depending on what your imagination says it looks like.
Both Jupiter and Saturn make their closest approach to Earth this month. Jupiter is at opposition on July 14 and Saturn on July 20. They will be above the horizon for most of the night and will be great telescope targets for the next several months.
Comet Neowise C/2020 F3 is a pleasant surprise right now. It was discovered in late March while the world was trying to figure out how to respond to a new virus. In mid-June, it was a binocular challenge, but after it made its closest approach to the sun it brightened significantly. Right now, it should be visible to the naked eye in the northeastern sky just before sunrise. Binoculars will help you find it in the brightening sky. This weekend it will be about 15 degrees below and to the left of the bright star Capella. Because it is moving from day to day, be sure to check a finder chart for its updated position.
Charles Hakes teaches in the physics and engineering department at Fort Lewis College and is the director of the Fort Lewis Observatory. Reach him at hakes_c@fortlewis.edu.
Useful links
Stars orbiting the black hole at the heart of the Milky Way:
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Comet NEOWISE finder chart:
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ASTRONOMY PICTURE OF THE DAY:
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OLD FORT LEWIS OBSERVATORY:
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AN ASTRONOMER’S FORECAST FOR DURANGO:
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FOUR CORNERS STARGAZERS:
