The Return of Solar Observing

As the days of British Summer Time get longer a compensation for me is that the Sun is rising high enough to be visible again from my northwest facing garden.

I love my solar observing in both the Hydrogen Alpha (Hα) wavelength of the Balmer series, using a Coronado Personal Solar Telescope (PST), and with a normal telescope in white light, but with a Herschel Wedge removing around 99% of the available light for safe observing.

Considering that we’re near solar minimum there’s been a surprising amount of activity to be seen around the end of March and the beginning of April. The most dramatic events have been in Hα, but even white light views have been impressive. The cause of the excitement has been a pair of large Active Regions (ARs).

The first of these (AR12644) produced some large eruptive prominences as it exited the face of the solar disc on 3 April. I was lucky enough to be observing then with the PST with a Baader Zoom eyepiece, and the events were fabulous.

I don’t image, and was too busy observing to sketch, but fortunately NASA does image almost continuously with the Solar Dynamics Observatory (SDO) from orbit. This is what they came up with, and despite their use of the ultraviolet part of the spectrum it’s not too far from the PST view in the red of Hα (656.3nm).

SDO image of AR12644 at 30.4nm taken on 3 April 2017
An image of AR12644 on 3 April 2017 at 30.4nm wavelength by the Solar Dynamics Observatory (SDO). Credit: Solar Dynamics Observatory, NASA.

It is just a little more detailed and has a larger image scale. They also have some movies of this solar eruption, and trust me, you could see that big prominence changing before your eyes!

I checked out the white light view too, but there was no indication of the violent events to be seen. The clusters of sunspots and surrounding faculae were plain to see in all their intricate detail despite sitting right on the limb in the image below. It was taken by the SDO HMI instrument, but is very similar to my white light view.

SDO HMI Intensitygram of AR12644 and AR12645 taken on 3 April 2017
HMI Intensitygram of AR12644 and AR12645 3 April 2017. Credit: Solar Dynamics Observatory, NASA.

In its wake followed the equally large AR12645 in the lower left of the image below. If anything it was more impressively detailed in the wedge, and I found it to be naked eye visible through some Baader solar film (another method for safely viewing the Sun). It didn’t produce any Hα fireworks, but the sharp filaments and swirling patterns in the spicule and fibril background of the solar chromosphere were beautiful to observe.

These ARs were great to view throughout their transit across the face of the Sun, but will they survive to reappear for another transit?

A Feast of Astronomical Observing

And now I’ve forgotten to post through March… which is a shame because it was a huge improvement over February. Not only a big uptick in the quantity of observing opportunities, but lots of variety in my observing diet too.

Both this month and the last have started with some Lunar observing. I’m starting to take this increasingly seriously just as the Moon is due to sink lower in my sky until it disappears behind the house until Autumn… still you have to start sometime, and I’ve decided now with the Charles Wood’s Lunar 100.

Which is why I’m very happy to welcome the return of solar observing. As the Moon sinks, the Sun is getting higher in our northern hemisphere skies, so it’s around now that I start to swap lunar for solar observing. Despite being around solar minimum, with relatively few sunspots to be seen, I’ve been rewarded with some Hα fireworks and spectacular white light sunspots in the last few weeks. Few in number perhaps, but the quality was undiminished.

Planetary observing wasn’t left out as I followed the sliver of Venus up to the last possible moment. For me that was the point it fell behind the houses and trees to the west at sunset on 15 March 2017, but it was a very thin crescent by then: I estimated 5% and Stellarium claims 4.4% illumination. I’ve caught a glimpse of Mercury at sunset too.

There were several Jovian sessions, even though it’s a bit too low to see well from my back garden. I can observe Jupiter low to the SE over the top of my garage for about 30 minutes before it goes behind the house. No moon transits yet, but a look at a slightly washed out Great Red Spot (GRS) was possible in my 60mm refractor. Why the small scope? To have any view I have to pick my position carefully, and you try manhandling a large telescope into the garden undergrowth.

I’ve tried to spot the comets 45P/Honda and C/2015 V2 (Johnson) with my binoculars, but with no success. At first they were too faint or low, then the Moon arrived and I haven’t bothered again. Once the Moon disappears I’ll certainly try again for the latter of the two at least.

March witnessed the arrival of British Summer Time (BST) which heralds the rapid shortening of night in these parts. Naturally in astronomical circles this is never well received, and Deep-Sky observing isn’t going to be easy! By the end of May there’s no astronomical darkness for a couple of months, but in the meantime there can be some lovely transparent skies for the patient.

After a rather wet period in the middle of March, during which the Moon got out of the way, clear skies returned just before BST inflicted itself upon us. I’ve started working on the Herschel 400 list again. This spread of several nights gave me the chance to start on the faint and fuzzy galaxies of Spring, as well as polishing off some surprisingly faint open clusters from late Winter.

Finally, I’ve collected a few more variable star observations thus clearing the backlog a bit and responding to an AAVSO alert on AG Dra (one I regularly follow). The conditions haven’t been great for it: patchy cloud doesn’t kill a lunar session, but it makes reliable binocular variable estimates pretty tricky. Still it’s nice to be logging some data again.

So a March was a much better month and April has started in stunning style with observing sessions on each of the first seven days!