andrew s

And the size of the market would be ? 😜

Nice write up. It is good to see that you can contribute to a longstanding effort in VS observations. Regards Andrew

Prof Nat Bastian gave us an update on the latest research in this area. He clearly showed how out of date the textbooks now are. Fortunately, I am not studying for any exam. Regards Andrew

Oh you old luddite @ollypenrice. Bet you can't process your images on an abacus. Regards Andrew

That was what was thought to be the case but it was a selection effect. We now know as per the talk that they form throught out time and are indeed forming now. Regards Andrew

A second flare. I promise not to post any more unless they are significantly different. Regards Andrew

I suspect seeing and sky transparency are dominant in the comparison. With out control of these variables scientifically robust conclusions are impossible to draw without a much wider statistically sample. Regards Andrew

If your using bass and you save the calibrated image the calibration will come back if you load the saved image. If you make it No 1 in the sequence then you can apply it to new spectra. Regards Andrew

@Stu, just how many eyes do you have? 52 scopes at one clear night a month leads to one viewing each a year! 🤔😂 Regards Andrew

I don't have an extensive list. Mainly, home made Newtonians with commercial mirrors from 6 to 16 inches with 8 and two 12 inch in between. The 16 inch was too big for the observatory so I gave the mirror away to a school and the 12 inch Zerodur mirror to my local astro soc. The mounts have been more interesting with Fullerscopes Mk2 and IV mounts then a Parallax mount with beautiful 12inch Byers worms and wheels which was destroyed in my observatory fire along with a 12 inch Newt. I then ( thanks to Direct Line) got a Paramount ME and I then finally replaced that with an MEII which is close to perfection. Regards Andrew

There is also a nice article by @JeremyS on it under the "Articles" tab on the BAA website. Regards Andrew

Well it's my birthday and everyone is sitting around falling asleep while lunch cooks. The wine is good however. Regards Andrew

They vary a lot but as @Grumpy Martian said you get out what you put in by and large. Regards Andrew

And it's the day before my birthday😱

It's a community and they come together for Xmas. Good wishes to all and a cloud free new year (at least at night). Regards Andrew

Nice work Louise, starting to look the business. What width slit are you using for the spectra above? Regards Andrew

@robin_astro yes very similar, although in the M dwarf case hydrogen beta and gamma grow strongly but don't seem to grow in your DN Tau flare. It will be interesting to see how they develop as the flate subsides. Regards Andrew

Here are the spectra of the rise phase of the flare. The smother black spectra is the average of the 20 spectra before the flare. Each exposure was 100s with 2.8 seconds download time. The increase in intensity in the UV end is about 5 times the non flare level. Giving the filtering due to the cadence it all took place in some 200s! As Robin commented you would not want to live too close. The fall phase is much slower and I have sill to process the spectra. Spectra processed in BASS with a linear wavelength calibration, instrument response from a HD34203 spectra and Pickles reference and filtered to match the sharpest HD3403 spectra as they are over sampled. . Regards Andrew

Following the terminology used with camera lenses the smaller the f number the "faster" it is. This comes from the ability to stop down a camera lens, reducing the aperture, and with a fixed focal length increasing the f number. As less light gets in the smaller aperture you need to increase the exposure compared the fully open aperture. Hence it is slower. Its use in telescope can be confusing and is much debated on here as the focal ratio myth. Regards Andrew

They probably added a anti-boost system without telling any one. Regards Andrew

If you go to the AAVSO web site and their "Light Curve generator" and plug in "alf ori" it will plot the light curve which does show it dimming slightly. If you plut in say 1200 days you can see its variations and that it is just slightly lower than previous minima. Regards Andrew

They tend to be high pressure and the line are very broad and washed out. Not ideal in my view. Regards Andrew

Mono camera and filters are not RASA friendly. Regards Andrew

A sparkling delight. Regards Andrew

Still to process the spectra ( work in progress) but here is a gif of the event. Blink and you will miss it! Regards Andrew