What's Up in the Night Sky

June 2025 - Vol. 29, No. 6

This Month's Night Sky - NOTE: The next paragraph describes the sky as it appears at 10 pm EST (11 pm EDT) near mid- month. The sky also looks this way at 11 pm EST (midnight EDT) during the beginning of the month and at 9 pm EST (10 pm EDT) by month's end.

Spica (Virgo) glows in the SW while Regulus (Leo) vanishes over the W horizon before midnight. The "big dipper" (Ursa Major's asterism) now stands on its "handle" in the North. Antares (Scorpius) is low on the S horizon. The Eastern sky is dominated by the "summer triangle" asterism: Deneb (Cygnus), Vega (Lyra) and Altair (Aquila). An interesting star tour begins at the last star of the big dipper's handle, Alkaid. Following the curve of the handle, "arc to Arcturus". Now, following the same curve, "spike to Spica" and "continue to Corvus", its distinctive four star, kite-shaped, asterism.

MERCURY, appears in the evening sky, favors observers in the southern hemisphere. VENUS, in the morning sky reaches greatest elongation on the first, favoring southern observers. MARS, visible in the evening sky, starts the month at +1.3 magnitude and ends the month at +1.4 magnitude. JUPITER lost in the evening twilight, reaches solar conjunction on the 24th. SATURN in the morning sky, reaches conjunction with Neptune on the 29th. URANUS begins to rise in the morning sky after last month's solar conjunction. NEPTUNE in the morning sky, appears to be near Saturn. (You'll need a telescope to observe Neptune.)

Review how to determine Angular Measurement.

Calendar of Events

NOTE: For those observers not in the ET zone, convert the calendar times to your zone's time by subtracting one hour for CT, two for MT and three for PT. Don't forget to adjust for Daylight Savings Time when necessary by subtracting one hour from your planisphere's time. Dawn and dusk times must also be corrected. See your local newspaper, TV news, or cable TV's Weather Channel for sunrise and sunset times or check with the U.S. Naval observatory. Unfortunately some of these events may occur during daylight hours in your area.

DATE	EVENT
01	Mercury at perihelion. Venus at greatest elongation W. (46 deg.) Mars 1.4 deg. S. of Moon. (not visible)
02	Alpha Leonis, Regulus 1.7 deg. S. of Moon.
06	Alpha Virginis, Spica, 0.5 deg. N. of Moon, occultation from S. half of Africa, Madagascar, Kerguelen Is., E. Antarctica, S. New Zealand.
07	Moon at apogee.
08	Mercury 2.0 deg. N. of Jupiter.
10	Alpha Scorpii, Antares, 0.3 deg. N. of Moon, occultation from Indonesia, W. Melanesia, Australia, New Zealand, Easter Is.
11	This month's full Moon is often called the "Strawberry Moon" as it is the month that strawberries ripen in North America. Mercury at greatest heliocentric lat N.
12	Venus at aphelion.
17	Mars 0.8 deg. N of Alpha Leonis, Regulus.
19	Saturn 3 deg. S. of Moon. Neptune 2 deg. S. of Moon.
21	Solstice, Summer in the North, Winter in the South.
22	Venus 5 deg. S. of Moon.
23	Moon 0.6 deg. N of the Pleiades star cluster (M-45). Moon at perigee.
24	Jupiter in conjunction with the Sun.
27	Mercury 3 deg. S. of Moon.
29	Saturn 1.0 deg. S. of Neptune Alpha Leonis, Regulus 1.5 deg. S. of Moon.
30	Mars 0.2 deg. S of Moon, occultation from NE tip of Russia, Hawaii, Galapagos Is., NW tip of S. America.

Lunar Almanac for June 2025

Phases of the Moon	Phase and Date(s)	Best viewed before local midnight
	New 25	Deep Space Objects
	1st. Qtr 02	Planets & Moon
	Full 11	Moon
	Last Qtr 18	Deep Space & Planets

Topic of the month: Boötes and Corona Borealis

As night falls in the Spring sky a bright northern star appears in the East. Truly the brightest star in the northern sky, Arcturus boasts of −0.05 magnitude. Throughout the evening, Arcturus marches prominently across the sky as Spring gives way to Summer. Its home is the constellation of Boötes, a kite-shaped constellation, referred to as "The Herdsman" or sometimes "The Plowman". Stargazers can find it by following the "arc" of the stars on the handle of "The Big Dipper" by the memorable instructions, "arc to Arcturus."

Arcturus and Boötes have colorful history. The name Boötes comes from the Greek word for herdsman. This is an ancient name for the constellation as later skywatchers also called the constellation, the "bear watcher", no doubt because it is close to the constellation Ursa Major (the Great Bear.) There are few interesting astronomical objects in this area because the constellation is far from the plane of the Milky Way galaxy. A small globular cluster, NGC 5466 can be found in the constellation, shining at 9.7 magnitude.

Another nearby constellation is Corona Borealis, also known as the "northern crown." The brightest jewel in the northern crown is the second magnitude star, Alphecca. Alphecca is the alpha star of the constellation and is also known by another name, Gemma. Alphecca has a magnitude of 2.2. A semi-circle of seven stars form a small crown-shaped constellation. It is fairly easy to spot from a dark site.

The Herdsman and the Crown — Corona Borealis and Boötes

finder chart for T Corona Borealis — T Corona Borealis Finder Chart

Corona Borealis has attracted astronomers' attention recently, as a recurrent variable star exists in this constellation. The star, T Corona Borealis is expected to brighten suddenly, up to magnitude 2.0. Although it was thought the star would erupt before September 2024, but that hasn't happened yet. Popularly called, "T Cor Bor", it's normally about 10th magnitude. Because of these outbursts, the star is known as the "Blaze Star"

In July of 2024, Astra's Stargate monthly topic covered the Blaze Star. That article includes a large finder chart and more information. Go to the article The Blaze Star, Awaiting the Outburst of T Coronae Borealis by following the link. Even from the city, a pair of binoculars can be used to discover whether or not the nova has occurred. When the news of its nova spreads over the internet, make sure you look quickly because it will only shine bright enough to be seen by the naked eye a short time.

--See You Under the Stars!
Astra for Astra's Almanac

The star chart above was generated by Stellarium, a free open source planetarium program. The above image was created by Dawn Jenkins, using Stellarium and a graphic editing program to format the image for this web page. Editing was done for educational purposes only. Stellarium offers much more to amateur astronomers and is being used in planetariums and to guide telescopes in the field. Simple charts like the one above can be used on the internet for non-profit, illustration purposes. Proper credit is due of course! Thank you to the makers of this fine program from Astra's Star Gate.