Sun rises at 5:46am
Sun sets at 6:32pm
Moon phase: 1st quarter moon, crescent waxing
Moonrises at 9:46am
Moonsets at 10:00pm
Super moon?
We have a new moon this weekend, a thin crescent that will follow the sun throughout its arc across the sky. The new moon this month is actually a super moon, which may confuse some of you who think of a super moon as a big beautiful moon that can almost take your breath away to gaze upon its brightness. Actually, a super moon is a closer than normal moon, and since we are in the phase of the moon that has us facing its darkened face, we can’t really see its super-ness, but the oceans will surely feel the stronger gravitational pull of the moon and will produce some higher high tides and lower low tides.
The crescent moon will hang in the western sky Saturday night, and the Winter Circle will be surrounding the moon. This brilliant ring of bright stars that we have admired for the past season now will soon be leaving us for the summer months. It is already low in the west at sunset, disappearing below the horizon early in the evening hours. Mars joins the circle this weekend, located between Aldebaran (in Taurus) and the Pleiades.
The year 2017 will have four super moons: the new moons of April, May and June, and the full moon of December. The new moon on May 25 presents the closest super moon of the year (357,265 kilometres or 221,994 miles). This is the first time since the year 2009 that the closest super moon is a new moon (instead of a full moon) and the first time since 2009 that the closest super moon is more than 357,000 km distant.
Tau Bootes?
And now a word about a faint star in the constellation Bootes, the Herdsman, that made astronomical history in the year 2007. In that year, an international team of astronomers, led by Jean-Francis Donati and Claire Montau of France, caught the star Tau Boötis flipping its north and south magnetic poles. These astronomers had been mapping the magnetic fields of stars. It was the first time a magnetic reversal had been observed on any star other than our sun. The astronomers published their work in the peer-reviewed journal Monthly Notices of the Royal Astronomical Society in 2008.
Astronomers intently watched Tau Boötis for more magnetic turnovers, and it appears this star undergoes magnetic reversals in periods of about every two years. They’re hoping Tau Boötis will enable them to understand how magnetic engines drive stars, including our sun. Our own sun’s magnetic poles flip about every 11 years.
You can see this star. Tau Boötis is faintly visible if you have a dark and moonless sky. Look eastward on these late April evenings for the blazing yellow-orange star Arcturus, the brightest in your eastern sky.
Don’t confuse it with Jupiter which is there also, for the next few months. To verify that you’re looking at Arcturus, look for the Big Dipper in your northern sky. Follow the arc of the Big Dipper’s handle to Arcturus. On these evenings, the star Muphrid shines to the upper right of Arcturus, and Tau Boötis lodges to the upper right of Muphrid.
May Day!
The first night of May, look for the moon’s shape to fill out to a nice crescent as it hangs close to the Twin Stars of Pollux and Castor in the constellation of Gemini. By this time, we will be halfway through the first quarter of the moon’s cyclic phases.
Thank you for keeping up with the Night Sky articles. If you are out later on in the week, each star rises about four minutes earlier each day than written here, and the moon rises 50 minutes later. Night Sky is researched and compiled by Lisa Davis-Burnett. Earthsky.org is a key resource for information and images. Questions or comments? Email This email address is being protected from spambots. You need JavaScript enabled to view it.
