December 1, 2019

Orion with the Mewlon: brighter, but is it better?

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Last week, it was clear for two nights in a row, with the Moon below the western horizon and all the bright planets setting soon after the Sun. A good time, I figured, to have a look at Orion - rising to the east at around 8 PM - and track down some double stars that I'd missed in years past. I've recently become much more interested in double stars, partly because I now imagine what the sky must look like from orbiting planets. 

On both nights, I was forced to use our observation deck. My daughter was a little sick, and I had to be on call in case she woke up and needed something. Since it's illuminated, the deck is a terrible place for deep space observation, but it's a whole lot better than nothing. Unfortunately, atmospheric turbulence was high and seeing on both nights was therefore somewhere between atrocious and worse than average. Not terrible for low-power observation of Orion and open clusters, but nowhere near good enough for splitting tricky double stars. 

The only picture that turned out: a selfie.

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​On night one, I stepped out with my Takahashi refractor: my go-to, all-around telescope, especially in cold weather. The seeing was then closer to atrocious, especially near the horizon, and views of Orion were not exactly the best I've had. I've focused on getting great equipment, but more often than not it's the atmosphere that limits what I see at night. On top of that, it was gusty on the observation deck: gusty enough to actually push my telescope. Not a great night, to put it lightly. 

Undaunted, I stepped outside on night two with both my TV 85 and my Mewlon. I observed for around 45 minutes with the TeleVue, lingering on the Pleiades and Hyades: brilliant open clusters that are now high in the sky and therefore spectacular at around 9 PM. The seeing was well below average: bad enough to notice at low magnifications, but not bad enough to spoil the view (in contrast to the previous night). 

After a while, I mounted my Mewlon. For over a month, I've waited for a sturdier mount to arrive from Stellarvue, but no success. I've had to cancel and go with another option, from the manufacturer of the only mount I have now: my VAMO Traveller. This mount is downright miraculous for its light weight and ability to handle substantial telescopes, but it's overmatched with the Mewlon.

The view was therefore a little wobbly, and the problem was compounded but two equally bad problems: the seeing near the horizon, especially with the higher magnifications that the Mewlon permits, and the thermal state of the telescope, which had still not cooled down in the low temperatures (it was around 7° C). Stars danced in the eyepiece, or even stretched into short lines: a bizarre effect that I've rarely seen. 

Still, by around 10 PM, at modest magnification, I did get a decent view of Orion: a great deal brighter and perhaps more impressive than what I'd seen with the TV 85. Rigel A and B were also much easier to split with the Mewlon than with the TV 85, though I did manage it through both telescopes in spite of the awful seeing. Castor A and B also made for a brilliant and impressive binary, though, again: it was hard to find the targets I was hunting for with the opaque sky (transparency was low) soaking up DC's light pollution. 

In short: not the best night for the Mewlon, and exactly the kind of conditions in which the TV 85 can match much bigger telescopes. As usual: I'm still happy I stepped outside! 

A different kind of view: the crescent Moon and Venus at sunset the other day.