The news is, of course, old to those who have been following the Sun’s activity of late: things are getting more exciting. There are more spots, more flares and more CMEs as we approach solar maximum. Solar Cycle 25 is off to a good start, and interestingly, there are websites which post that it will be weaker than 24… while others show that it will be more active. Official news can be found here:  https://spaceweatherarchive.com/2022/01/09/solar-cycle-25-update/

Right now the sunspot counts are higher than the predictions for the cycle. Read into that as you will, as solar physics is still a burgeoning field. The current prediction is for the cycle to reach maximum in mid-2025. With that amateur radio enthusiasts and astronomers will enjoy the changes to the Sun and ionosphere. With the activity, changes to our solar observing practices have been made, so that it can be shared safely with students & adults, and the data collected to send to the AAVSO Solar Group. While all but the 0.7m have solar filters, the results of using a Herschel wedge from Baader along with a 10mm Radian and polarizer on a TV-85 have been amazing. It’s small, light weight, easily transported and will also hold a Nikon D-810 for imaging. Attached are a couple of photos from earlier this week, all taken in gusty wind conditions. Note that if you are intending to get new solar observing gear, the lead times on ordering gear are now long… and solar maximum is coming. Images are below: be sure to click to see full size. The spots are impressive!
Clear skies to all.

With this winter term’s Selected Topics in Astronomy class, we chose to give the new 0.7m telescope a workout and see if it could produce results fine enough to detect extrasolar planets using the transit method. The transit method focuses on the slight apparent brightness changes in a star when one of its planets orbits in front of it from our viewpoint here on Earth. Many planets have been discovered this way: The Kepler Mission has over 2800 candidates and 2600 confirmed. The TESS mission has over 2600 candidates and 122 confirmed exoplanet discoveries. So, where to start?

We chose a well-known exoplanet, visible to us in the northern hemisphere, with a predicted brightness change that should be readily visible to our equipment. The predicted transit times needed to be well established and had to start and end during nighttime, so that we could detect the entire transit event. WASP-43b became the primary target. It has a 0.81 day orbit (FAST!) and is a large planet orbiting a small diameter star (spectral type K7 V), making for large changes in brightness. All we needed was a clear night when one of its transits was taking place. Using the Swarthmore exoplanet transit search site (https://astro.swarthmore.edu/transits/transits.cgi) we found a perfectly good transit opportunity on the night of 26 January. The goal was to start photometric observation an hour before the transit started, observe through the entire transit, then end an hour after the event. The goal was achieved!

Images were taken in rapid cadence, one minute integrations each, through an Rc filter to minimize the Earth’s atmospheric effects.

The image above shows the results of the data capture: two plots. The upper plot shows the magnitude of WASP-43 changing through the transit period in J-C Rc magnitudes. X: Time in J.D. Y: Rc observed magnitudes. The bottom plot is of a check star used to validate the data set. We used reference and check star Rc magnitudes from the AAVSO for this study. Note the error bars are small: these represent systemic errors in the measurements based on signal-to-noise values of the individual images. The variances in magnitudes, which are on the order of 0.010 mag, are caused by atmospheric changes and seeing conditions. Exeter, NH is very close to sea level, so we have a lot of air mass to observe through. With these conditions the dip of about 0.040 magnitude in WASP-43’s brightness was easily seen: a success!

This is also an indicator of the observatory’s capabilities. We now know that a typical winter observing run can expect 0.010 magnitude fluctuations in seeing conditions and that a star with m=12, we can expect an excellent signal-to-noise ratio. What’s next? To work on assisting scientists with solidifying the orbital periods of other less known exoplanet systems.

Those looking up at the sky through late November to late December are in for a real treat, a close conjunction of Jupiter and Saturn. This is quite an event! It will be easily visible to those with or without optical aid. It takes place early in the evening, so even those who go to bed early can enjoy. All you need is a clear early evening and a low horizon to the southwest. Here’s a short video to show you more. Enjoy!

https://youtu.be/rKwFqnVdKiM

Last night’s target now processed… stage 1…. the initial offering. Sometimes I remain happy with the first edit, sometimes not. This is NGC6888, the Crescent Nebula in Cygnus. The central star is known as a Wolf-Rayet star, WF 136, which is massive and rapidly shedding its outer laters into the surrounding interstellar medium. This whole system is about 5000 light-years distant and about 25 light years across. This image was taken with our 0.7m telescope through several filters: Luminance is a combination of one hour of clear plus one hour of Ha. The color data was taken using Ha, SII, and OIII narrowband filters.

Comet Wirtanen has been giving us a moderate showing this time around the Sun. As it has been closer to Earth than it usually gets, we are enjoying a comet that might just get bright enough by December 16th to see without a pair of binoculars.  Last night we checked it out through the school’s 16″ telescope and took some images as well.

Comet 46P/Wirtanen: One is through the 16″, the other is a wider field view through a telephoto lens. The brilliant green color is striking and caused by the excited gases: cyanogen (CN)₂ and diatomic carbon (C₂).