Early June Evenings, 2021: Arcturus, with the constellation Boötes, is high in the south as evening twilight ends. The constellation seems to follow or chase the Big Bear westward. Most people recognize the body and tail of the Bear as the Big Dipper.
by Jeffrey L. Hunt
Step outside and look southward at the end of evening twilight during early June. (That’s about 10:30 p.m. CDT in Chicago. In regions farther west in a time zone, the minute hand of a clock could be turning toward midnight. For example, in North Platte, Nebraska, evening twilight ends at 11:20 p.m. CDT on June 7.)
The bright topaz star Arcturus, over two-thirds of the way up in the south, is at the meridian.
The meridian is the imaginary line in the sky that divides the rising stars from the setting stars. When a star is precisely south, we say that it is at the meridian or on the meridian.
When the sun is on the meridian, the time is local noon.
Arcturus is the brightest star in the northern half of the sky, noticeably brighter than Vega. It has a luminosity of 200 suns at a distance of less than 40 light years.
The name is thought to be derived from “Arktos,” meaning bear. The full name is thought to mean “bear guard.” The star belongs to Boötes, the “herdsman” or “ploughman.”
Peter Lum, in The Stars in our Heaven, stated that the name means “ox-driver” (p. 73). The pattern resembles a traditional kite shape. Drawings show Boötes with a sickle and a club.
Boötes seems to be chasing the Big Bear westward. Find the Big Dipper pattern, the brightest seven stars in the bear, to the upper right of the herdsman.
Gemma, the brightest star of Corona Borealis, is about 20° to the upper left of Arcturus. The Northern Crown appears as a broken circle.
With the moon in the morning sky, a darker sky is ready for a detailed inspection. Messier 3 (NGC 5272) is a globular star cluster just beyond the limit of eyesight in Canes Venatici – the “Hunting Dogs” – 11.9° to the upper right of Arcturus. The cluster is at least one-third of the moon’s apparent diameter. Use a binocular or small telescope at low power to see it.
In The Messier Album, Mallas described the view through a telescope, “A very remarkable cluster; extremely bright and very large” (p. 39).
Take a look southward during early June. The moon returns to the evening on June 11, appearing near Evening Star Venus. View the constellation and try to locate the star cluster before the moon brightens near mid-month.
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- Mars during 2021 (Summary)
- Planets during June 2021
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September 30, 2021: An hour before sunrise, the crescent moon is near the Gemini Twins.
September 29, 2021: The thick crescent moon is in the southeast before sunrise, approaching the middle of Gemini. The evening planet pack is visible after sunset.
September 28, 2021: This morning the moon, as it approaches its Last Quarter phase, is high in the south at the Gemini – Taurus border. The evening planet pack – Venus, Jupiter, and Saturn – brightly shine after sunset.
September 27, 2021: Before sunrise this morning, the bright moon seems caught between the horns of Taurus, Elnath and Zeta Tauri. The planet pack, Venus, Jupiter, and Saturn, are visible after sundown.