Hello members! International Dark Sky Week is fast approaching! In lieu of doing public events, we have secured observatory access every day and night from April 22-30 inclusive. As a reminder, this is for members and their guests only. Note also that April 30 marks the new moon and our mostly monthly Dark of the Moon viewing. If you'd like to take advantage of our dark skies, send an email to your favourite president to make sure someone can be at the observatory to meet you there.
The spring Pelee Island wine sale has begun. Orders are due by Monday April 18 at 16:00. Wines include a Pinot Grigio 2020, Tailwind Cab/Cab 2016, Ruggles Run 2017, Secco 2018, Vinedresser Chardonnay 2017, Belle Sparkling Rose 2020, J.S. Hamilton White 2017, and Vinedresser Meritage 2016. Purchases can be made through this link here. Support the BEF and OEC, and enjoy great wines at an excellent price!
Keep an eye out for zodiacal light following sunset for the next couple weeks. Caused by light scatterring by interplanetary dust, zodiacal light is seen as a faint, diffuse, and roughly triangular white glow that appears to extend from the Sun's direction and along the zodiac, straddling the ecliptic.
Sirius, the alpha star in the constellation Canis Major, is the brightest star in the night sky shining an apparent magnitude of -1.47. In 1844, it was deduced from changes in the proper motion of the star that it must have an unseen companion. In 1862, this companion was finally observed and is dubbed Sirius B or "the Pup." Shining at a blistering apparent magnitude of 8.44, this star is almost as elusive to the amateur astronomer as Carmen Sandiego is to the ACME Detective Agency. All is not lost however! Keep reading to learn how you can resolve this binary star for yourself.
Sirius B orbits Sirius A over a period of about 50 years. See below for a picture of what this orbit looks like with positions plotted by year. Over the course of its 50 year orbit, the separation between the two varies from 3" to 11.5". Since 2000, the separation between the two is increasing, and its next maximum is 11.28" in 2023.
Maximum separation should make resolving the Sirius binary star easier, but this is not the whole story. Excellent seeing is also required. Seeing refers to degradation of an astronomical object due to turbulent airflow in the atmosphere. Poor seeing can manifest itself as blurry objects, twinkling or variable distortion. Consulting a tool like the Clear Sky Chart can help determine when viewing of Sirius might be best.
Finally, to give yourself the best chance of resolving the binary star, choose a night where Sirius is higher in the sky (December-March), and use high magnification. Let your instruments cool down to ambient temperature. Consider using an occulting bar to block the glare of Sirius A if you're having difficulty. Another strategy is moving Sirius A just out of the field of view to see if Sirius B presents itself. Good luck!
References and for more info:
Spaceweather is reporting possible auroras on the next few nights. This is the result of a coronal mass that was ejected from a flare near a centrally-located sunspot earlier today. It is expected to interact with Earth over the weekend - a good time to see aurora (if weather cooperates). Oddly, the flare that originated the ejection occurred at the site of a minor sunspot 2962 as in the image below. And a much larger sunspot group 2965 is slowly rotating into alignment.
With all that has gone on in the world, even in my generation (especially in my generation), and what has gone on these past 2-3 years, even at home here in Ottawa, Quebec, the GTA, and the provinces west of Ontario, especially Alberta, we all should spend a minute or two and watch and listen to this video. To give it some context, on February 14, 1990, Voyager 1 was leaving the solar system when, at the request of Carl Sagan, it was commanded by NASA to turn its camera around and take a last photo of Earth across a great expanse of space. The voiceover is by Carl Sagan. You would do well to listen to it attentively! Afterwards, look at your children, grandkids and great-grandkids and do some thinking.
A number of astronomy news sources have recently reported on an asteroid called “1994 PC1” which is due for a flyby of the Earth-Moon system on January 18. There is no chance of collision since the miss distance is over five times the Moon-Earth distance (or about two million km or so). The neat thing about this is that at its closest, 1994 PC1 should be detectable in small telescopes as a moving 10th magnitude point of light. You are encouraged to go out and have a look. If you locate it and make note of its position with respect to other stationary stars, you should be able to see its motion in 10 or 15 minutes. The asteroid is moving about 2° per hour so it will cross a 0.5° field of view (a medium power eyepiece) in 15 minutes.
I have provided a finder chart below (about 15° across) of a small part of the sky in Pisces during several hours on January 18. Here is the link to the EarthSky.org report with more details.
The asteroid is about a kilometre across - the size that would not be a “planet killer” if it had actually hit Earth. Still, had the impact point been Owen Sound, for example, everything from Collingwood to Wiarton would have been destroyed, with a crater at the impact point about 10 km across. Even Toronto would experience a shock wave that would knock buildings down and most of SW Ontario would notice something, except in Ottawa, where the politicians would not notice much happening in Grey-Bruce.
If you are interested in exploring asteroid impact damage more, a scientific analysis of these is available here.
The area of interest is near the star Alrescha, where traditional stick figure diagrams show the Pisces fish “tied together.” The second attachment is a wider view chart showing Pisces and its surrounding constellations with the asteroid labelled in red. This view is at 20:00 EST, and the asteroid is 45° high at that time. Sunset is at 17:13 that evening, and the sky will be as dark as it will get that night by 19:00. However, the just-past-full Moon will be rising a half hour after sunset so there will be moonlight that night. Send me an email if you have any luck spotting it. Imagers out there are encouraged to capture this event. The 1994 PC1 close encounter will also be livestreamed on Virtual Telescope. Good luck and stay safe!