For the next few evenings – April 19 to 21, 2018 – look for the moon and Winter Circle (or Winter Hexagon) stars. It’s difficult to convey the humongous size of the Winter Circle that fills our western sky at dusk and nightfall. It even dwarfs the constellation Orion the Mighty Hunter, which makes up the southwest portion of this a great big lasso of 1st-magnitude stars.
Look for a circular (or hexagonal) pattern of bright stars around the moon these next few nights. Just be sure to look at dusk and nightfall, because the Winter Circle stars will sink below the horizon by early evening.
And if you’re out there looking soon after sunset, you might also see a very bright planet. In fact, it’s the brightest planet, Venus, shown at the bottom right on the chart above. The moon has moved up past Venus over the past several evenings. Watch for it!
The Winter Circle can be seen from around the world, although its orientation with respect to the horizon will be different, depending on where you are.
No matter what part of Earth you’re standing on, though, this same pattern of bright stars will surround the moon around April 19 to 21.
If you’re in the Southern Hemisphere, notice that the sky’s brightest star – Sirius – will appear at the top of the Circle and the star Capella at the bottom (if you can see Capella at all; it’s far to the north on the sky’s dome).
The Winter Circle stars are bright, but the brightest starlike object in the sky on these April 2018 evenings is the planet Venus. Venus sits quite low in the west at dusk and sets at or near nightfall.
Bottom line: Use the moon on April 19 to 21, 2018, to find the bright stars of the Winter Circle!