Archive for October, 2007

Comet Watching

On the way home from soccer practice tonight, there was a message on my cell phone. I checked the message and it was from my daughter’s astronomy course teacher, Blair. His message was for her to check out the naked eye comet 17P/Holmes in the Northeastern sky, as they were going to be discussing it in class this weekend.

The comet which is periodic (comes around every 6 to 7 years) usually is not very bright. It is normally considered to be a magnitude 17 comet, meaning that you need a very powerful telescope (and dark skies) to see it. Suddenly on the 24th of October, 2007 the comet brightened about a million times to approximately a magnitude 3 object. For an example of magnitudes, Vega the star that is virtually overhead in the summer is a magnitude 0 star and Sirius (the star to the lower right of the constellation Orion) is a magnitude -1.42 and is one of the brightest stars in our skies. The larger the magnitude number the fainter the object.

No one knows what caused the brightness this time, but theories are that there may be ice under the surface, or that a piece broke off or it cracked and is now a pinpoint star surrounded by a glowing halo. The comet also displayed some of these characteristics when it was discovered in 1892.

Currently the comet is located in the constellation of Perseus. If you are looking North find the constellation that looks like like a large W (Cassiopeia), then start looking further North and East of Cassiopeia. While it could be considered a Naked Eye object, from our part of the city it is difficult to see as there is a major shopping center just northeast of us, including a large Wal-Mart. Unfortunately the sky glow from the shopping centre really washes out the sky.

Anyway while the kids were getting ready for bed, I went out with my 10×70 binoculars and tried to find it. It took me about 20 or 30 minutes but finally I caught of glimpse of a large fuzzy object. Once I found the comet it was very easy to find it again. I brought out one of my telescopes (SkyWatcher 102mm ED) and a portable mount, found the comet and got the kids. Everyone came out and had a look at something that you don’t get to see very often in most peoples lifetime. The comet appears to be a bright object surrounded by a large round halo. There is no real hint of a tail as the comet is moving away from the earth so if there is a tail we cannot see it.

If you want to see some images of it visit this site as it shows recent brightening Nasa Astronomy Picture of the Day You can see the comet’s orbit here; Comet 17P/Holmes Orbit

The comet should stay in the constellation Perseus for a couple of months now. Unfortunately we don’t know how long it will remain visible. If you get a chance to check out this comet in the next few days I encourage you to do so. Check out the Friday Night Deck program at the Telus World of Science where, every Friday night where volunteers from the Calgary Centre of the Royal Astronomical Society if Canada man telescopes for free public viewing. I am sure there will be more than one scope trained on this fantastic object.

If Halloween night is clear, I plan on setting up a couple of scopes in the driveway as well as a tripod mounted pair of binoculars and offer the little trick or treaters and their parents a special little treat from the sky!