This Week’s Sky at a Glance, 2025 June 14 – June 21
This Week’s Sky at a Glance, 2025 June 14 – June 21
Five millennia ago, Persian and perhaps Egyptian astrologers designated four of the first magnitude stars (the 20 brightest) as Watchers of the Sky, with each guarding one of the four cardinal directions. With their proximity to the Sun at the equinoxes and solstices they were also used to mark seasonal changes. Collectively, they were known as the Royal Stars.
Regulus in Leo and Antares in Scorpius were two of the Royal Stars, and we see them now appearing through evening twilight. Regulus guarded the north and marked the summer solstice, while Antares guarded the west and marked the beginning of autumn. Fomalhaut, in Piscis Austrinus below Aquarius, guarded the south and marked the winter solstice. Aldebaran, currently rising in Taurus half an hour before sunrise, guarded the east and marked the spring equinox. These stars no longer mark the seasons as they did 5000 years ago due to precession of Earth’s polar axis, which makes one complete wobble every 25,800 years. On the summer solstice, the Sun is now located near the border of Gemini and Taurus.
None of the Royal Stars make the top ten in brightness. The brightest star in the sky for this time of year, Arcturus, is at its highest at sunset. It precedes almost equally bright Vega, which anchors the Summer Triangle with Deneb and Altair. Vega reaches its highest point around 2:30 am, half an hour before Fomalhaut rises . These two stars are the same distance from us at 25 light years.
This Week in the Solar System
Saturday’s sunrise in Moncton is at 5:27 and sunset will occur at 9:11, giving 15 hours, 44 minutes of daylight (5:35 and 9:13 in Saint John). Next Saturday the Sun will rise at 5:28 and set at 9:14, giving 15 hours, 46 minutes of daylight (5:36 and 9:15 in Saint John). The summer solstice occurs on June 20 at 11:42 pm.
The third quarter Moon is approaching Saturn on Wednesday morning and it is just east of Saturn on Thursday. By next weekend the Moon will be having breakfast with Venus. Mercury sets 80 minutes after sunset this weekend and increases that to 95 minutes by next weekend while dimming somewhat. Jupiter is too close to the Sun for observing as it approaches conjunction. The highlight of the week will be orange Mars sitting a little more than a degree above blue-white Regulus on Tuesday evening, and they will easily be within a binocular field all week.
Tune in to the Sunday Night Astronomy Show at 8 pm on the YouTube channel or Facebook page of Astronomy by the Bay.