February 21, 2023: Use a sky map to find the winter morning stars. The Moon joins Venus as it approaches Jupiter. Mars is traveling east in a planetary display.
By Jeffrey L Hunt
Chicago, IL: Sunrise, 6:38 a.m. CST; Sunset, 5:31 p.m. CST. Check local sources for sunrise and sunset times for your location. Times calculated from the US Naval Observatory mica Computer program.
Transit times of Jupiter’s Great Red Spot, when it is at the planet’s center in the Southern Hemisphere: 7:49 GMT, 17:45 UTC; February 22, 3:41 UTC. Convert the time to your timezone. In the US, subtract five hours for EST, six hours for CST, and so on. Use the telescope to see the spot. times of Sky and telescope magazine.
Here are the forecasts for today’s planet:
Morning sky without a bright planet or moon. Mercury rises just 36 minutes before sunrise in the bright light of approaching dawn. Saturn rises a few minutes before sunrise. It is lost in bright sunlight for about the following month, and appears in the eastern sky just before sunrise at the time of the equinox.
This morning’s chart is a circular map showing the entire sky an hour before sunrise. These charts can be confusing because of their orientation and circular shapes.
First think of a floor map. Where are you when you look at a map of the Earth? You are in the sky looking down at the ground on the ground, north at the top of the map and east on the right.
When contemplating a celestial map, the observer of the sky is on the ground looking up. So, the circular map is the sky above your head with the top point marked with a “+” sign. Directions are usually marked with cardinal points letters. On the accompanying map, it was generated from the US Naval Observatory mica computer program, directions are determined with their azimuth: north is 0 degrees; east, 90 degrees; south, 180 degrees; And west 270 degrees.
In theoretical use, hold the map above your head and rotate the circle to match your bearings. Quickly, you’ll see this is inconvenient and you’ll be chasing a digital sky map. However, there is an easier way.
Hold the map in a comfortable position and rotate it in the direction you are looking for. For example, start with Antares. It is located near the horizon circle, low to the south, on the map. This is where it is in the sky during late winter an hour before sunrise.
Now look east. Rotate the map so that the east is at the bottom. Note that Vega is more than halfway between the eastern horizon and the upward-pointing “+” sign. You will be halfway up in the eastern sky. Dhumb is less than halfway between the eastern, northeast, and upper horizon, while Altair is about a third of the distance between the eastern, southeast, and upper horizon. The two stars are in these places in the sky.
Note that the morning sky has other bright stars, including Spica, Regulus, and Arcturus.
An example of checking your ability to read a celestial map is locating the Big Dipper on the chart. What direction will you look and how high in the sky to find it?
This evening, the crescent moon, 4% lit, joins Venus and Jupiter in the western sky.
Start looking west-southwest at 45 minutes after sunset. Bright Venus is approximately 20 degrees above the horizon, with Jupiter 8.2 degrees to the upper left.
The Moon is 6.4 degrees to the lower left of Venus. Note the brightness of the Earth in the night part, and the sunlight reflected from the features of the Earth brightening the darkness of the Moon.
The three most beautiful celestial bodies at night are located within a circle with a radius of 15 degrees. This does not happen frequently. Tomorrow the assembly is inside the 8 degree circle.
Venus quickly overtakes Jupiter, cutting the gap by about 1 degree, the diameter of two full moons, each evening. Venus transits Jupiter on March 1stStStaying within 10 degrees until March 11thy.
Farther east Mars is marching east in front of Taurus. An hour after sunset when the faint stars are visible, Mars is high to the south, 10.2° to the upper left of Aldebaran and 7.1° to the lower right of Elnath, the southern horn of Taurus.
Over the next week, watch the Red Planet pass between Elnath and Epsilon Tauri (ε Tau on the chart). The second star is part of the “V” group that defines the bull’s head. Epsilon is located at the top of the V opposite Aldebaran. Speculum may be required for identification. It is much dimmer than the stars in the Pleiades star cluster, at its upper right.