| Observatory |
Some observing hilights
to look forward to...
The following tips on current and upcoming astronomical events
have been gathered from magazines and other sources by Dave Gamble
with the objective of giving OC RASC members a heads-up on
special personal astro-experiences to look forward to.
Wed. Aug. 1 – A panorama of planets can be seen spreading across the southern sky on the first night of August. First visible as the sky darkens is brilliant Venus which will then introduce Jupiter and then Saturn. The interest builds as this summer’s lead actor Mars then takes the stage low in the southeast. The best part of it is that the performance will run for most of this month!
Fri. Aug. 3 – The waning gibbous Moon will provide a fingerpost to the blue-green ice giant Uranus tonight. The outer planet will be seen about three finger widths above Luna.
Sat. Aug. 4 – This is Last Quarter Moon night as our neighbour starts to move out of the night hours, leaving an enlarging dark sky period available for deep sky enjoyment.
Mon. Aug. 6 – The waning crescent Moon will rise in the early morning hours, comfortably ensconced in the Hyades open star cluster in Taurus. Another signal that seasonal change is not that far away is the fact that this beautiful group of stars is continuing its march westward in preparation for its annual performance in the late fall and winter skies.
Sat. Aug. 11 – This is New Moon night with our neighbour completely out of the night sky, marking the centre part of the dark sky period for deep sky viewing, sketching and imaging.
Sun. Aug. 12 – One of the main annual meteor showers, the Perseids, will peak tonight, this time with the Moon safely tucked away only one day past New Moon. Though the peak will occur this evening, be sure to look for harbingers the night previous and stragglers the night afterward. This can be an outstanding show!
Mon. Aug. 13 – It was an important time in ancient Egypt when astronomers, and presumably agriculturists, looked for the first sign of Sirius rising in the east–southeast. In the era of the Egyptian empire it was the signal for the coming of the annual flood of the Nile. In our epoch and location this now takes place about 20 minutes before sunrise around mid August. If you should wake early and spy the helical rising of the sky’s brightest star, it could be taken as signaling the imminent approach of the Okanagan apple harvest.
Tues. Aug. 14 – As if in a late summer dance, the thin waxing crescent Moon will join the brilliant evening star Venus, cradling the star Porrima between them. Gamma Virginis may be the faintest of the group by far, but it is interesting to note that at home 38 light years away it is actually a binary system made up of two similar sized stars. While too close to separate in a telescope right now, their mutual orbit around each other will widen enough to reveal the pair in moderate telescopes by around 2020.
Thurs. Aug. 16 – Eager for another celestial meet-up, tonight the almost first quarter Moon has moved along to the vicinity of Jupiter which happens to be located about a moon’s width above the magnificently named star Zubenelgenubi, also known as alpha Librae which shines from 77 light years away.
Fri. Aug. 17 – Venus has reached the full extent of its performance as our evening star. Tonight it will be at greatest eastern elongation from the Sun.
Sat. Aug. 18 – This is First Quarter Moon night with the neatly divided sphere placed high in the sky to add beauty and drama to the Okanagan evening.
Mon. Aug. 20 – Tonight the waxing gibbous Moon is in the vicinity of Saturn, making the third of its visits to the string of visible planets available to it this month.
Wed. Aug. 22 – Tonight Mars is the bright planet welcoming the engorging gibbous Moon. Right now our lunar neighbour’s path lies well above the planetary ecliptic so it will appear almost the width of a fist above the red planet.
Thurs. Aug. 23 – For those who enjoy seeing Jupiter’s moons in action, tonight there will be a double shadow transit by Io and Europa. Io’s shadow will come onto Jupiter’s face at 7.02pm and Europa’s will join it at 7.35pm. Io’s shadow will leave the banded disk at 9.11pm and Europa’s at 9.50pm.
Sun. Aug. 26 – Before Dawn this morning, as the Full Moon is setting in the west, the innermost planet Mercury will be rising low in the east - northeastern sky. The innermost planet has now reached its greatest western elongation.
Sun. Aug. 26 – This is Full Moon night with the perfect orange sphere rising over the eastern mountains to begin an evening survey of how the ripening Okanagan fruit crop is coming along.
Mon. Aug. 27 – For those who would like to add the bluish outer planet Neptune to their list of observations, the Moon will make it easy tonight. The just past full Moon will be just a bit more than the width of a finger below the ice giant.
Thurs. Aug. 30 – You can tell we are nearing fall when word spreads that the Zodiacal Light is becoming visible in the pre-dawn sky. While the ZL is most often mentioned in the spring months when it appears in the western sky, the same applies in fall except that the triangular glow is seen in the pre-dawn eastern sky. The ghostly Zodiacal light arises when the Sun illuminates dust particles in the equatorial plane of the solar system.
Fri. Aug. 31 – The Greeks called planets ‘wandering stars’, and due to their orbital motion, together with Earth scooting along its orbit, the planets are seen to move among the stars nightly. All this to say that Venus has now cozied up to the position of the star alpha Virgo, better known as Spica (pronounced SPEE-ka). This is actually a very close pairing of binary stars which orbit each other every four days, an astounding 250 light years away. Both members are large stars, and the primary has more than ten times the mass of our Sun and is seven times its radius. Which is why we see it as a bright star despite its great distance.