Sirius is one of the brightest stars in the sky, usually clearly visible without binoculars or a telescope if city lights aren’t interfering. What we call Sirius is actually two stars, Sirius A and Sirius B; however, Sirius B so small that it is visually upstaged by Sirius A. The simplest way to find Sirius is to find Orion and use the belt as a signpost. In the Northern Hemisphere, winter nights after 9 p.m. are among the best times to look for Sirius using Orion's Belt as a guide. In late winter/early spring, look due south for the bright star itself.
If you live in an area where man-made lighting is particularly bright, you may have to travel outside the area to see stars clearly.
You may not need to use Orion’s belt to find Sirius in late winter and early spring; Space.com ranks it at the top of the list of brightest stars, so try looking due south. It should outshine the surrounding stars.
Sirius isn’t viewable in summer because its rising and setting times coincide with those of the sun. In fact, according to Cornell University, the phrase “the dog days of summer” stems from observations of the ancient Egyptians and Romans that Sirius might be working with the sun to produce all that heat. Due to a phenomenon called precession, Sirius now conjuncts the sun starting earlier in the year.
In the Southern Hemisphere, according to the Sydney Observatory, Sirius will be almost overhead during March; in June it is visible in the western sky after sunset, “about two fists in altitude above the horizon.”
Look toward the south-southeast to find Sirius in winter in the Northern Hemisphere.
Locate the constellation of Orion, particularly the three stars of Orion’s belt. Focus in on the leftmost star of the belt.
Hold your right arm out straight with the right edge of your fist adjacent to where you see the leftmost star. Rotate your fist diagonally so it continues the left-and-downward slant of the belt. According to Space.com, one fist equals about 10 degrees of sky when held out at arm’s length.
Place your left fist next to your right, also diagonally. Sirius should be at the left edge of your left fist.
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