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Seeing the Veil August 17, 2007

Posted by dorigo in astronomy, personal, science.

Yesterday evening the sky above the Dolomites did not promise anything good. Scattered low clouds, little wind, and high humidity were telling me I would have rather watched TV than carry my telescope to some remote place in the hope of observing the sky’s wonders, ending up staring at steady clouds. What was making me even more gloomy were the forecasts and the numerical simulations of cloudiness above northern Italy, which concurred in predicting a disturbed night.

But I had an obligation. Mauro, current director of the Mechanical Engineering department at the Trento University and fellow galaxy chaser, was determined to give the night a try, having been unable to observe from a dark site during the last couple of weeks, and with only a few days before the moon would start to prevent deep sky observations. He was leaving from his home near Venice, driving two straight hours to get to our favourite observing site, Casera Razzo – a place near Sella di Ciampigotto, 1800 meters above sea level and at least 10 kilometers from the nearest city lights.

So I wearily packed my telescope in my car. My equipment for an observing night with the 16″ dobsonian scope consists in a 2’x2’x2′ wooden box with the mirror housing, the rails, and the base, another 20″x20″x3″ wooden box where the mirror is stored for transportation, a long box with eight aluminum poles and hardware bits, plus the 18″x10″ cylindrical upper cell with the secondary mirror and focuser. Then there is a 24-hour suitcase where I store my eyepieces, the finder scope, and other miscellaneous stuff, and finally a bag with a pair of binoculars, my laptop, and a book or two. I am pretty well organized these days, so packing the stuff in the car takes only about 10 minutes, but it involves some wrestling with cumbersome pieces down the steep ladder leading out of our apartment…

And so, as dusk turned into night, I drove to Casera Razzo. 45 kilometers of mountainous roads. I drove with little hope, but by the time I got to the site a wonderful milky way was there to greet me. But it did not last long: low clouds encircled the site, until only a star here or there was punching through.

Mauro arrived late -no surprise-, and as he saw the messy sky he suggested to move to another site only a couple of miles away. His theory was that warmer air from the valley below was rising to the plain of Sella Ciampigotto, then pouring down into clouds as it found colder temperatures.

And he was right! As we settled and started to mount my dobsonian scope, I could see the clouds low to the west, but the sky above us was perfect, dark and clean, with a limiting magnitude of 6.5. Wonderful!

We observed many faint galaxies, as our agenda dictated. But the Veil Nebula – a complex mesh of filaments spanning more than three degrees of sky in Cygnus, the remnants of one or possibly two supernovae exploded 15,000 years ago – was too inviting to not give it a look.

The Veil is cataloged as a series of distinct nebulous objects – NGC 6960, 6979,6992, 6995. It is located at about 2,500 light years from us, and its integrated visual magnitude is about 5, but I have never heard anybody claiming to have seen it with unaided eyes, although theorically possible: the object is projected against a background thick with milky way stars, and it is quite extended.

Now, I had seen the nebula with my 16″ dobsonian scope under similarly dark skies bafore. But I had never had the opportunity to look at it through a O-III filter – a filter that selects the doubly-ionized Oxygen emission lines at 4959 and 5007 angstrom of the nebula, cutting away almost everything else. Mauro provided the filter, I framed NGC6960 (the eastern end of the ring, close to 52 Cygni) in the finder, moved to the eyepiece, and my jaw dropped! Not only did the filter enhance the tenuous luminosity of the nebula, making it jump out of the eyepiece. It also revealed tiny filamentary details which I had only seen in the very best long-exposure pictures of the subject. I was amazed.

On the left you can see a wide field SDSS picture of the complex nebula. It consists in a ring broken in several points, almost circular in shape, to which is added another arch, incomplete and almost intersecating with the first.

I am always wary when people tell me they see color in bright nebulae observed with telescopes – the human eye does not recognize it well enough in objects below a certain surface luminosity. However, with the filter the nebula seemed to have been stripped off any color at all. It shone with a cold silvery gray, almost metallic. That is the price to pay for an observation with narrow band filters such as the O-III.

Below is another image of a small part of the object – this time in color, and taken with the Hubble. Believe me, the amount of detail of the intricate wisps of this picture does not make me envious – the view through an amateur scope with dark skies and the proper filter can raise your hair just as much. I now understand why some vote the Veil Nebula the most beautiful object in the sky.



1. Tripitaka - August 18, 2007

I’m not a sky watcher but I caught the excitement, a most enjoyable post T! Mind you, if I could get to see things like that Hubble shot I’d be outside every night.

2. carlbrannen - August 19, 2007

This is a classic post. I loved the description of the instruments.

I set up two telescopes for my neice and nephews in the high dry air of New Mexico’s Sandia mountains one night this past summer. They assisted, and got to see Jupiter, Venus, (should have seen Saturn), a few random M objects (I don’t know the sky very well and didn’t have an easy way to figure out what was available, so I used one of the scope’s pointing features to guess around Scorpio and Sagitarrius.) The next morning, before dawn, I got them up to goggle at the half moon.

By the way, I seem to be studying chess again, in preparation for nailing down a rating.

3. dorigo - August 20, 2007

Hi Tripitaka,

thank you… And of course you CAN see things like the hubble. With whatever instrument, and SOME imagination… 😉

Hello Carl,

I will be more technical next time if you enjoy that… I envy the New Mexico skies!!! Here in Italy we dream of that kind of darkness. I think it is a big attraction to amateur astronomy, and I trace the diffusion of astronomy in the US to that factor.

If you want an estimate of your chess rating, why don’t you take my test ? It is at http://www.pd.infn.it/~dorigo/myold.html (link in the lower left column, “get your elo here!”). Be sure to let me know how yours turns out.


4. dorigo - August 20, 2007

Oops, link not working. Try this one instead: http://www.pd.infn.it/~dorigo/rating.html


5. Fred - August 21, 2007

I give up. I am not going to take the test. Could you give us the strongest answer for Diagram #1? How do you assess a board when you first observe it? What would you say are the weaknesses in your current game? Did you ever develop a killer instinct for playing competitive chess? Who would you say was the most ruthless chess player for the past century?

6. dorigo - August 21, 2007

Hi Fred,

why not ? The worst that can happen is that you input random digits… The test does not tell you answers other than a single number, your elo as estimated with some stupid math and checking your moves against a few lists relative to the positions.

Anyway, in diagram 1 I think the move is Rxf3. It is a grandmaster game, but I forgot which. I will find it and get back to you.

The first thing I do when I look at a board is not to count pieces but to look at the position – pieces are 95% of the times almost level anyway. You get most of the story about the past of a game by observing the structure of the pawns. Then of course I try to understand whose move is it…

I have many weaknesses, my worst one is that of being lazy (prefer to play by intuition after some analysis, rather than performing a completely deterministic search). But that depends on the kind of game I am playing. My most structural weakness is the lack of a up-to-date opening preparation and the narrow opening repertoire. Then, I am not very keen of closed positions where strategic manoeuvering is the salt.

I never had a killer instinct. I have always tried to play with stronger opponents (by participating in open tournaments etc.) and with masters, international masters and the like you only try to survive or force a draw.

Ruthless is a complex concept. To be ruthless you have to be strong, for sure. In chess, being ruthless requires you to end up the winner of the game. I think both Fischer and Kasparov are the prime examples of players which were very tough to deal with. But in the past, probably Capablanca gave headaches to most.


7. carlbrannen - August 21, 2007

The first time I took it, I got 1690. Then I went back to actually write down moves and save them, didn’t give quite the same answers, and got 1730. Either of these is at the very high end of where I would think I should be.

A 17-year-old junior / senior in high school I showed it to got a 1550. And he did it extra fast. For some reason, my “5 minutes per move” got translated into “5 minutes for all 10 positions”. One of the differences between us is that I went for the win in the endgame with bishops on the same color squares, but threatening to sacrifice for promotions simultaneously on both wings. I think both these numbers are more than just a little optimistic.

Overall, I used to be lousy at openings, okay at midgames, and pretty good at endings. So a lot of my games involved losing a pawn early on and spending the rest of the game trying to claw my way out of the hole.

It’s been some time and my memory may not be perfect, but my version of my chess career is that my senior year I was the best player at our high school of 2000 students and was the 1st board on the chess team, which took the New Mexico state high school team championship that year. I know that the Albuquerque high school team champion was Del Norte, but I remember that we beat them at the qualifiers for the right to represent Albuquerque at the championship. My senior record was 50% against two other 1st boards (WL and DD), with every other game a win.

The 2nd board on that high school team was Steve Elliott. Randomly, we ran into each other when we both showed up as physics grad students at U. Cal., Irvine. He got his PhD there and is now at Los Alamos, (the home of one of our opponents for the state championship) specializing in neutrino experiments.

8. carlbrannen - August 21, 2007

Also, I should mention that I bought a few more chess books. I picked up one giving a course in ending theory. But the most interesting one for me, and one I will likely use, is the controversial book Rapid Chess Improvement. The things he says ring very true to me. For example, I automatically know how many moves it takes to get a knight between certain pairs of points, why not drill and know all of them?

For those wondering if it’s any good, here’s the rather convincing tournament record of Timothy Brennan, who wrote a positive review on Amazon.

9. Alex - August 22, 2007

wearily = warily

24-hour suitcase = we just say suitcase, the term 24-ore e’ soltanto usato in Italia

Complimenti for the will to observe – I would have never left my house under such conditions! 🙂

10. dorigo - August 22, 2007

Dear Alex,

my English is not perfect, and I salute any attempts at helping me improve it – grinding my teeth if they are impolite, or with a smile otherwise.

In your case, I smile – for the additional reasn that you attempted to suggest a change of meaning. No, I did mean “wearily packed my telescope”, not “warily”. I wanted to convey the lack of enthusiasm, rather than the caution. Would you mind leaving me the choice of adjectives ? This is my blog after all…

As for 24-hour suitcase, thank you for the note. Still, this blog is read by italians, for which “24-hour suitcase” conveys the image of my equipment much better than just “suitcase”.

About the hunger to see the stars – I really have few nights of dark skies per year, and Mauro forced me to enjoy one more than I would have otherwise… But yes, it took some effort to get moving with those clouds lingering around.


11. carlbrannen - August 22, 2007

“24 hour suitcase” meant to me a suitcase small enough to carry 24 hours worth of things, that is, a smaller suitcase.

Well I managed to find Fritz 8 + ChessBase for sale at Frye’s for $10. I picked up two copies, one for me and one for the 17-year-old who also took your chess test. It is a wonderful program, and I am going to have to put up a blog entry extolling its features. It has a rating feature which can be set as weak as 1620; I might be able to draw it with a little luck.

I am afraid that this is going to severely cut into my physics, at least until I can shake this job and retire.

12. dorigo - August 22, 2007

Hi Carl,

well, yes. That is the way we call such things in Italy in fact…

Fritz 8 is immensely strong. Even when set at such low rating setting, it will not be easy to beat it. It will make the occasional weak move, but you need to spot it, otherwise it’s over!

Chess is quite dangerous for physics indeed. Be careful!


13. carlbrannen - August 22, 2007

I’m planning on testing the “rating” version of Fritz 8 on Sunday, maybe two games. I will try to work up as much of a sweat as if I’d paid an entry fee at a real tournament. Already I love the way it analyzes games, the user interface, etc.

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