The Orionids, Panstarrs, and the moon at its apogee

Fred Barrett | Oct 04, 2017

This month has a great meteor shower – the Orionids. The peak occurs just before dawn on the 21st of October and more than 20 meteors an hour can be expected.. The bonus for this year’s maximum is that the sky will be Moon free! The frequency of meteors slowly ramps up from early October and after the peak, decreases until it ends in early November. Essentially, the Orionids can be seen through most of this month. The Orionids are debris left behind by Halley’s Comet as it makes its periodic trips around the Sun and as the Earth passes through the orbit of Halley every year, we see the flashes and trails of this debris burning up in the atmosphere as meteors. If you were to draw a line back along the meteor trail of all the Orion meteors, you would end up at a point in the constellation Orion. This point is called the radiant and since it is in Orion, the shower is called the Orionids. Orion is just below the eastern horizon around 10 pm at the beginning of October and rises above the horizon as night progresses. By the 21st it is above the horizon and gets higher at 10 pm as the month advances. It contains the visually stunning Orion Nebula.

You can try your hand at another object in the sky this month. It is Comet Panstarrs. It is about 30 degrees above the eastern horizon near the Pleiades star cluster at 11 pm or so. You will need a telescope with at least a 4 inch mirror. Since the Pleiades are relatively near and to the upper right of Orion, I have included its path in my drawing of the radiant in Orion. The numbers along the path indicate the date and position of the comet during October. Panstarrs is heading off in the direction of the Oort cloud and back to where it came from.
In the evening this month, Jupiter and Saturn can easily be found in the west. Venus is a morning star this month and along with Mars can be seen before sunrise in the east.
What else can we find this month?

October 5th: Venus is very close to Mars at sunrise. It’s also the date of a Full Moon and that officially occurs at 2:40 pm. It is named the Full Hunter’s Moon or Full Harvest Moon. It’s pretty easy to figure the why of those names. Think of lots of bangs in the woods and succulent venison. If you have a largish dog, don’t forget to dress him or her in the brightest orange when you go out. Make the trip to walk the mutt a short one if possible and it might be wise to dress yourself in bright orange too! October 10th is Thanksgiving when we enjoy and celebrate the bounty of harvest time. American Thanksgiving is much closer to winter. Actually it is winter by then! All the venison and harvest stuff must be frozen.

October 9th: The Moon is at perigee (closest), 364,700 Kms.
October 21st: Orionid Meteor shower peaks at dawn.
October 24th: The Moon is at apogee (farthest), 402,800 Kms.

We had a close lightening strike a few weeks ago that fried just about every piece of electronics plugged into the house electrical system including the 1 year old computer that I use to research and type this column. I suppose I could have looked up info in my astronomy library and written the column out in long hand and hand delivered it but I was too busy repairing and replacing my smoking electronics. At least the house didn’t catch fire. I wouldn’t wish a mess like this on anyone!
Keep looking up!

“The Beginners Observing Guide” by Leo Enright is an invaluable companion to find adventure in the sky. It contains star charts and is packed with information. It can be purchased at the Sharbot Lake pharmacy or can be ordered from the Royal Astronomical Society of Canada at www.rasc.ca/publications. A subscription to our very own excellent Canadian astronomy magazine, SkyNews, can be ordered at the RASC website as well. Email me at fred.barrett2@sympatico,ca to ask questions or report any unusual sights in the sky.

Clear skies, Fred