Skywatch with Bill Irwin

At the time of writing this we are having a real cold snap. Often it is clear at night during these Arctic outflows and if the moon isn’t interfering, those bright winter stars can be spectacular, with Orion the hunter leading the charge in his constant battle with Taurus the bull. Gemini the twins are riding high overhead, and the hunting dogs, Canis major and minor, follow the hunter’s path in the southeast. Sirius is the bright star in Canis major and is the brightest star in the night sky. Because of its low elevation and great brightness, Sirius is affected by atmospheric turbulence. It often twinkles and shows colours as refractive cells of air move in its light path. This is quite noticeable, and people often wonder what it is.

At the observatory when it’s around -20 degrees C or more, I usually spend more time inside the warm room than out on the observing deck where the telescopes are. The grease starts getting stiff in the scope’s focuser, and cold eyepieces easily fog with your breath. I think about making a glassed-in dome at these times. You’re not supposed to look through a window with a telescope because it degrades the image, but I’m actually surprised how good it can be, especially with binoculars.

But you don’t want to hear about winter anymore. As the evening wears on you will see the unmistakable reverse question mark of Leo the lion rising in the east. Spring is on the way. Soon it will be time for the realm of galaxies, especially between Leo and Virgo.

In spring and fall we look outward from the disc of the Milky Way galaxy, rather than through the thick part of it like in summer and winter. As a result, we can see much farther outside our own galaxy and find ourselves looking at other galaxies.

Galaxies are faint looking smudges for the most part and require larger telescopes to see well visually. The more you look at them, the more you can see, and comments like,“I can’t believe I didn’t see that last night” are common. One of my favourites is the Sombrero in Virgo. It is very striking with its dark dust lane girdle. You have certainly seen it on TV if you watch old science fiction movies or The Outer Limits.

The planets had a good showing last year and are taking a bit of a holiday this spring. Venus, which has been that spectacularly bright object in the early morning sky, is drawing closer to the sun and will be on the far side of it in superior conjunction before it re-emerges into the evening sky later this year.

Mars is also fading as it approaches conjunction low in the western sky at sunset. Last year’s opposition was a close one, but dust storms on the planet itself made the July 2018 opposition challenging as far as making out details on the planet’s surface. The opposition of 2020 looks to be a lot more promising, because Mars will be much higher in the sky and we may escape the dust storms this time. No backyard observation of the planets can match what you can see on Hubble images or rover panoramas or simulated flyovers you can see on the internet. But only by getting out under the stars and trying to observe them can you get an actual sense of where they are and how they move. Then you have some place to put all the other data.

Saturn and Jupiter are low in the southern sky in Scorpius and Sagittarius. They will be mostly visible in summer; that is, if we don’t have a mosquito season like last year.

The full moon in spring is interesting. We all have visions of the Harvest Moon in fall. It appears to linger in the sky for several nights around the full moon. But the full moon in spring doesn’t elicit the same memories because it rises an hour and 20 minutes later each night versus the 20 minutes or so in the fall. So, if you are in the habit of looking at your usual time, the full moon only puts in a brief appearance. The moon is not moving significantly faster or slower in its monthly journey. It moves about 13 degrees a day. In the spring the path it takes at full moon is steeply inclined to the horizon, whereas in fall the full moon’s path is shallow. Since it can be cloudier in spring as well, that makes seeing the spring full moon’s romance more of a one-night stand.

As usual, the Bells Lake Observatory, near Horsefly, BC can be reached at irwin8sound@gmail.com. The galaxies are waiting.

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