Planning An Observing Session, Plus A Surprise Shower !!!
Observing the night sky comes in two flavours. The first is the spur of the moment feeling of grabbing binoculars or a small scope as we fly out the door. Here we spend about 20 minutes looking at our favourite Messier or NGC objects as well as the moon or planets thus satisfying our need to observe photons. The other more involved task is planning a lengthily observing session either in the backyard or an out of town expedition. Lunar and planetary observing.. and photography do not need dark country skies.
Depending on the nature of the upcoming session, a great time of planning and preparation can go into this. First check your social calendar for some family or friends celebrating a birthday, etc. If you are wishing to hunt deep-sky objects, checking the phase of the moon would a great idea (looking for a 14th magnitude galaxy during a full moon is not fun, challenging, but not fun).
If you are travelling to a remote location far from home base you might want a plan of attack as in what to observe and/or image. This way you are not losing precious time deciding “what shall I look at next”. Unless that is what you wish to do. There is no wrong way to enjoy the starry landscape.
Ensure all telescope and camera equipment are in good working order and ready to go. You do not want to leave that important cable sitting at home about 100 km from your site or have a dead battery. Safety is another concern. If you really insist on venturing into nature alone, advise either family or friends your exact location and route taken in case you do not return the next day. Cell phones are great but you might not have reception in case of a medical emergency or car troubles.
Bring healthy snacks and lots of fluids but be aware of nature and their keen sense of smell. An inquisitive bear or pack of coyotes can really put a damper on your night. Enjoy your food and drink in the car and keep stored in a cooler.
Other great locations to observe are Provincial Parks and campgrounds. Many of these sites are located far from light-polluted cities and towns. When making reservations, ask if there is an open field you can use for night time viewing. Astronomy is one hundred percent weather-driven and an unfavourable weather forecast can bring your plans to a screeching halt. Check predictions for your driving destination and not where you live. Weather can be quite different an hour’s commute away.
During the month of May, the planet Jupiter reveals itself a few minutes after the Sun sets in the west. The King of planets is still nestled high in the western sky in the constellation Gemini – The Twins. To the upper left of Jupiter, we have the two heads namely Pollux (bottom of the two) and Castor which make a fine trio. Throughout the month the moons of Jupiter cross the planet’s face and cast shadows. Consult pages 231 – 236 of the RASC Observer’s Handbook 2014 for times and remember to convert to your particular time zone from UT.
Looking to the east we catch the orangey tint of Mars. AKA the Red Planet, Mars and Earth are now separating in distance after last month’s opposition. As Earth is moving faster than Mars in our separate orbital paths, keep following Mars as it continues to move west against the background stars (retrograde) in the constellation Virgo until May 21 when it becomes stationary and begins to move eastward after that date. As you can see by the diagram all planets retrograde do the Earth overtaking the planet around opposition. Mars will pass some 19 arc minutes north of the magnitude 10.5 elongated galaxy NGC 4546 on May 31. Although Mars is glowing at magnitude -1.5, over the next weeks and months Mars will shrink in apparent size and gets dimmer and dimmer until its next opposition some 25 months from now.
Saturn is by far one of the most beautiful objects you will witness in an eyepiece of a telescope. The famous ringed planet is located in Libra and will be closest to Earth (opposition) on May 10. At magnitude +0.1 Saturn is fairly bright and appears a slight tingle of yellow. Planets move slowly across the sky so once you have located a planet for the first time, it will be in the same area against the background stars for the most part night after night. The moon, on the other hand, the moon moves about 12 degrees of sky from night to night or a bit wider than the width of your fist extended at arm’s length.
Now if deep-sky is your cup of tea and you have access to dark skies, you might want to spend a lot of time this month examining the cluster of galaxies located between the constellations Virgo and Coma Berenices. This massive swarm of distant galaxies is located to the left of Leo the Lion. Scanning the area with larger scopes and wide-angle eyepiece will reward you in numerous finds. Years ago I had access to a 20-inch Dobsonian telescope and the scanning was memorable.
One particular observation was the duo of M84 and M86. Of course, seeing a pair of galaxies is great but there were another six NGC objects around them. Yes, that is right, eight galaxies in a single view. My knees buckled for obvious reasons. This gorgeous grouping of starry islands is at the end of a line of galaxies to the left called Markarian’s Chain branching off to the east. The only problem you will have when looking for a particular galaxy within the swarm is the low number of bright stars help guide your path. This is called star hopping. When dealing with the Virgo Cluster, you literally have to galaxy hop. As the night moves on you will notice the majestic veil of the Milky Way rising in the east. To end of the night as dawn breaks around 5 a.m. local time and you are packing up, Venus breaks above the SE horizon. On May 15 Venus slides south of the planet Uranus by 1.3 degrees or almost three full moon widths.
Circle your calendar for May 23/24 as you might be witnessing the astronomical event of the year. It all stems from the path Comet (209P/Linear) being perturbed by Jupiter and now the comet’s orbit will be passing closer to Earth. If the weather holds, southern Canada and the United States are the only places in the world with a ringside seat. Elsewhere the shower will be facing away or just occurring in the daylight.
With the radiant being set at 8h 16m, +79°, the shower is named the Camelopardalids and with some very interesting predictions. For now, estimate rates are from 200 to 400 meteors per hour with a slim chance of that rate moving to 1,000 per hour. The expected peak should be from 5:40 to 8:50 UT but you should watch all night just in case it flares beyond predictions. These will be moving very slow and graceful at only 16 km/sec compared to the Perseid’s 72 km/sec. With a crescent moon, only 4 days from new and the date is Friday night into Saturday morning, the weather would be your only excuse for not seeing this event. Even pesky mosquitoes will not factor into the night. So dress up the family and head for clear country skies as this show may only return in 2019 with lower rates of 50-100 per hour along with a 72% lit moon rising at 1:07 a.m.
This month’s full Flower Moon occurs on May 14 and the new moon on May 28. I hope everyone enjoys Astronomy Day on May 10. Here is where local astronomy clubs and centres do what we do best and share the love of the sky with the general public by day with exhibits and by night with star parties.
Until next month, clear skies everyone.