Summer Time Treats part 1

As you plan your upcoming camping trip or simply unwind at the cottage, do not forget to pack those trusty binoculars or telescope. These out of town destinations are great for relaxing and enjoying nature at its best. Numerous activities can be done in the light of day but a different form of entertainment awaits an hour after sunset. Try to take advantage of real dark skies when being away from the dome of light pollution that plagues our cities and towns. When planning your nature getaway, check the calendar to see when the brilliant moon is out. Even in the great outdoors, a full gibbous moon can easily wash out the delicate Milky Way overhead thus turning country skies back to city status. There are too many great objects to recap in one article so let’s break it up into two columns.

Chart 1

We will start from the low southern sky at Scorpius the Scorpion. Antares dubbed the “Heart of the Scorpion” from mythology is a spectral type M1 red giant star that has ended its fusion process at the oxygen/carbon level and has moved to its final stages of life. Antares resides 556 light-years (ly) away has already swelled in size to about three astronomical units or if it replaced our Sun would balloon to the orbit of Mars. For astrophotographers, Antares along with the close globular cluster M4 helps frame a much larger portrait, the Rho Ophiuchi cloud complex. This colourful collection consists of dark nebulae, red emission nebulae producing its own light from radiant stars as well as blue reflection nebulae. Rho Ophiuchi is a triple star located at the top of the image. Before you venture away from this area, be sure to take a look at planets Mars and Saturn. Mars is now moving easterly and you can follow its path all month as it moves closer to Antares.

Look a little to the east until you locate to the end of the Scorpion and the two stars that make up the imaginary “stinger”. From here move a few degrees east and you will see a very larger open cluster catalogued as M7. Referred to as Ptolemy's Cluster, this collection of some 80 stars is located 980 (ly) from us. Measuring 25 light-years (ly) wide, M7 is set against a backdrop of millions of stars. One summer I had observed this cluster's reflection off a calm lake, what a memorable sight that was. Keep moving east until you come across the asterism of Sagittarius the Teapot. This connection of eight suns clearly represents a “teapot” in the night sky with what appears to be “steam” is the glow of the Milky Way. From Alnasl, located at the top of the pot, move six degrees north to a misty region called the Lagoon Nebula.

Here we see star birth in motion. At about 4,700 ly away, M8 is barely at naked-eye visibility and measures more to two full moons in wide. This region visually appears grey but shows up as a reddish or pinkish cloud when photography is involved. This is the telltale sign that hydrogen gas and dust is slowly condensing and collapsing to form stars – a process taking millions of years. Also seen to the fainter side of M8 is the open cluster NGC 6530 comprising of young stars estimated to be only a couple of million years old. Moving your scope one and a third degrees north and a bit west is M20. Widely known as the Trifid Nebula, M20 resides about the same distance as the Lagoon. It is a star-forming region symbolizing a three petal flower. Both objects can be seen in wide-angle binoculars.

Chart 2

Many fantastic globular and open star clusters swarm around the hub of the Milky Way galaxy. One of my favourite globulars is M22. Located a bit more than two degrees east of the star at the tip of Sagittarius named Kaus Borealis, an orangey spectral class K1 star located 77 ly away, M22 is an even splash of stars taking on the appearance of salt grains on black velvet. M22 is a pleasing magnitude 5.1 and estimated to be more than 10,000 ly away.

Continuing the tour up the Milky Way, we come to the Swan Nebula. Catalogued at M17, it is also known as the Omega and the last Messier (M) object before we leave the constellation boundaries. The Swan is yet another emission nebula located 5,000 ly away and dimly glows at the naked eye limit of 6.0. Shades of red and pink are evident in photos but any bright stars are hidden within the nebula’s environment. We will continue our tour next month.

Jupiter can now be found sinking lower in the western sky every night. Both Mars and Jupiter are still brilliant objects but Mars is slowly beginning to dim as it moves farther from us. All planets including Earth travel along an elliptical orbit around the Sun. On July 4 our planet will be at aphelion or its farthest distance from the Sun 152,103,000 km at 16 hours UT. The planet Venus has now peaking close to the Sun’s disk and is moving into the evening sky. It is still too close to the Sun to safely look for it but as July marches on, it should be easier to spot low in the west after sunset.

The Delta Aquarid meteor has a long period from July 12 to August 23 with July 28 being the peak night. This shower always runs during the Perseids in August. This year’s Delta Aquarid with not have a pesky moon to contend with as the 25% waning crescent will rise at 2:05 a.m. At its best, the shower can produce from 10 to 20 meteors per hour or ZHR. In past years only 5% of the meteors produced a smoke trail or train behind it. This month’s New Moon (lunation 1157) occurs on July 4 at 11:01 UT and the Full Thunder Moon on July 19 at 22:57 UT.

Until next month, clear skies everyone.

Gary Boyle

Twitter: @astroeducator

eNews date: 
Friday, July 1, 2016