Seeing through clouds? Ya gotta be kidding!

OK, if I didn't have an excellent witness sitting beside me, I would not have believed it myself, but yes, I can now see through solid cloud cover with telescope and video camera! Maybe this is old hat to some, but in my half-a-century of off-and-on amateur astronomy, I always thought seeing through clouds was a joke.

In fact just a few days ago I was scheduled to be one of the participants from the Astronomical Society of Southern New England at a public school event in Barrington and as the day got cloudier and cloudier one of the suggestions was to let our guests decide on their own whether it was too cloudy to come to the event, or not. I turned to my wife and said: "Yeah - that will work. I mean people already seem to think we can see through clouds with our telescopes." ;-) Laugh out loud. Well the event was cancelled at noon and a good thing - solid cloud cover. But . . .

Last night my friend Danny asked if he could check out an eyepiece I was selling. I said "sure" and he said he would be out at 8. At 7:59 it was nearly totally clear. Danny arrived at 8 and we took 10 minutes to meet the puppies before going to the Observatory. Bummer - 95% clouds! (What was it Mark Twain said?) But I had set up the scope earlier and done a two-star alignment, so it now knew how to find things on its own and hold them in view. We quickly directed it to a faint cluster, M67 - that was in one of the few clear holes. Danny got a quick look, then that closed down. But wait! Orion was opening up. Perfect. We swung to M42, the beautiful nebula with its exquisite group of four young stars known as the "Trapezium."

Terrific. It not only stayed clear long enough for Danny to test the eyepiece against one he had brought, but also for me to pop in the MallinCam Color Hyper camera and show Danny what it could do. Well, he seemed impressed with the first, two-second "integration" that appeared on the screen, but then I switched to six seconds and 12-seconds. And in his usual, understated way, he commented in an email: "I was very impressed with the live view." Yep. But the best was yet to come.

We talked about the wonderful detail and subtle color in the nebula, but at this long exposure rate - 12-seconds - the Trapezium was so bright it was all washed out. (This is where your eyes do better than the video camera - they have an incredible dynamic range. So while the video shows color and detail our eyes would not pick up, our eyes would show us both the nebula and the Trapezium, being able to adjust for vast differences in brightness. ) But as we sat and talked some more, the nebula started to vanish - the clouds were gobbling up Orion as well. In a couple of minutes we were looking at the Trapezium and three nearby stars in a row. The Nebula itself wasn't coming through, but these stars were.

"How faint do you think they are," Danny asked.

"I don't know - about magnitude 8, I suspect."

Here's a simulation of what we could see (click for a larger image in separate window):

Well, the actual magnitudes of what we could see range from 5-to-8.5, as I learned when I looked at the chart in the Starry Nights software this morning. Now here's the astounding part. When we turned away from the television screen - a small, portable DVD player I use - we could not see a single star in Orion - not even the bright giants Betelgeuse and Rigel! Not one of the stars in what is one of the brightest of constellations, was visible to the naked eye - solid cloud cover - yet when we turned back to the screen, there they were! And not the brightest stars - the telescope wasn't point at those. The brightest stars it was pointing at were ones you can barely see here on the best of nights, and most of these stars were far too faint to see with the naked eye from here.

I have to admit that I never thought I would see the day when I had a telscope that could see through solid clouds!

Ok - does not that mean we can observe any night? No. Obviously we were losing a lot of detail. And just as obvious, I have no way of knowing how thick the clouds really were. Should we have held that event for the public despite clouds - absolutely not! But I'll tell you this, if there is some special event in the future, such as an eclipse, or occultation, or even just a nice double star that I want to show people, I'm not going to give up just because of clouds, light pollution, or twilight conditions. If I can put the telescope on automatic so it can accurately find things without my being able to see them, then I know there's a chance the video camera might grab stuff I can't see.

OK - we probably should have looked through the telescope visually under those conditions as well just to learn what was visible. Some of you may be shaking your heads right now and saying - "Damn, Greg, you've been observing all this time and didn't know telescopes could see through clouds! You must be from another planet, fella "

You got that right! But I love it when things still surprise me, so ignorance - if that's what it is - can be blissful when suddenly removed. ;-)

Comments? EMail them to me and I'll post them here: gstone@umassd.edu

from Tom mote3.14.07

Greg,

Amazing that you were able to record those stars through a solid overcast. . . On a trivial note, it reminded me of one of the worst cases of sun burn I ever had after spending a day at the beach under a solid overcast.
:-[
Tom

and my response . . .

Hi Tom:

Actually, I did NOT record them - that's just a screen shot from Starry Nights - sorry for the confusion - however, we did see them absolutely that clear and , if I had connected the DVD recorder, we could have recorded them. But I knew the clouds were rolling in, so I made no plans to record. This was an entirely serendipitous event and as such, is an interesting lesson - at least for me.

Boy, i can well imagine getting a bad sun burn that way - clouds throw you off guard - but it's good to know I';m not theonly one who finds it a bit unusual to see 8th mag stars through solid overcast. Since the video camera goes a couple magnitudes deeper than the telescope, it stands to reason you should see some stars with the scope - maybe the brightest of the trapezium ones. I just never dreamed of looking for anything on a cloudy night. I've always assumed that if I can't see stars with the naked eye because of clouds, then one can be seen.

On March 18, Bob Magnuson wrote:

Hi, Greg

I've been up to my eyeballs in stuff and didn't have a chance to get here.

Well, I'm amazed. I mean, if you think about it, a video cam is pretty
sensitive, but I never would have even thought that stars would show
through clouds. However, Tom's comments about sunburn make me wonder if the
video is picking up another frequency of light that can penetrate the
clouds just as the UV rays did to Tom on that cloudy beach. So perhaps what
you were looking at was not visible to the eye. Dang, a view through the ep
would settle that question for sure, but I'm willing to bet that if you
could not see the stars naked-eye at all, then I'm betting you wouldn't
have seen them in the ep. Points of light are not one of telescopes' strong
suits. But the video cam is seeing stuff outside the naked-eye spectrum
almost for certain, and that is probably what you saw. But, like you, I
love serendipity, and I'm always amused when something like this turns up
totally unplanned.

But what do I know? That is just a pure guess...

Man, you do keep pushing the envelope, don't you?

Bob