A repost of the original at the Syracuse Astronomical Society website.
Greetings Fellow Astrophiles!
As much as I enjoy the outdoors, I do hate the heat. This is why I try to get as many viewing sessions in as possible during the Summer and stay inside otherwise. We remain optimistic for a clear viewing session this coming weekend with some planet-searching to boot(es)!
Perseid Update: What Was…
A small group of new and old members opened Darling Hill Observatory (DHO) at 8:00 pm on August 11th for the Perseids. This year, the evening/morning of 11/12 was predicted to be the peak for night viewing (the actual peak occurred during the day, but that big bright ball occasionally over Syracuse takes care of any daytime viewing). The evening also offered an early view of Jupiter and a good later (approaching midnight) view of the Moon through the 16″ Cave. The sky was 1/3 clouded over, but the clouds were localized with large open patches of what made for perfect viewing…
…of things that were NOT meteors. After 5 hours of viewing, I counted 3 total (one was quite impressive, the other two not so much). I suspect the tally among all visitors to DHO would have fit comfortably on two hands.
While out near downtown Syracuse on the 12th, a night so cloudy that Jupiter itself was obscured to the point of being completely unidentifiable, I counted 11 meteors between 10:30 and 11:30 p.m. before clouds devoured the entire Night Sky. Go figure.
Viewing Update: What We Hope Will Be…
This weekend is shaping up to be a well-attended Public Viewing session in lieu of an official Summer Seminar (see last month’s newsletter for more information), with several emails from individuals and small groups already exchanged. Jupiter will be a primary focus for the 16″ Cave for the visitors, but we also have Neptune just at the far edge of the border for the Constellation Capricornus that we can see as a dim blue sphere through most of the large scopes on the Hill. Uranus, closer to us than Neptune by nearly 10 Astronomical Units, will rise later in the evening and will, weather permitting, be an additional target for the evening.
The alignment of Uranus, Neptune, and Jupiter along the ecliptic in Aquarius and Capricornus at midnight on August 21.
The image width represents (roughly) a pinky and thumb extended at arms length.
And, for viewing of another kind, I have word from Peter Plumley, Exhibits Project Manager at the MOST, that they are working on the Space Science Series Lectures for the 2009-2010 season. With luck, we’ll have a schedule in time for the September newsletter.
News From The SAS Website
If you’ve not seen it yet, the link to the facebook page for the SAS is on the front of the website. We’ve already 8 members and are starting the process of committing content to the facebook page (well, at least, directing people to the Newsletter and Observing Information). The Directions page on the website has also been brought up to modern day with the inclusion of a google map of Darling Hill Observatory, complete with a satellite view of the grounds and a drive-able map for those looking for better directions than can be had over the phone during a poor-connection cell phone session.
Darling Hill Observatory, now on google maps (someone missed a branch on the driveway during the clean-up)
If you click on the “Ter” button (terrain), you’ll note that DHO is at approximately 1700 ft, a number that only becomes large when you drive from Syracuse in jeans and a T-shirt at 9 pm and find yourself huddled next to a space heater at 10 pm.
Everything Must Go (To The Observatory)!
A repost: I was forwarded the following list from SAS member Lee Polikoff, who is selling quite the considerable astronomy rig. The complete set, for which he is looking for $900 (but, of course, contact him if you want to spend much much more (or, well, ask him about the other direction as well), is as folllows:
* Celestar 8 Deluxe (8″ Celestron Faststar compatable OTA (some small scratches on the OTA finish). Mount has the Easy Latitude Adjustment kit. Mount has been retrofitted with the updated PEC correction chip from Celestron)
* Telrad finder
* Celestron Standard 9 x 50 Finder
* Celestron f6.3 Focal Reducer/Corrector
* 40 mm Pro-Optic Plossel
* 25 mm Pro-Optic Plossel
* 17 mm Pro-Optic Plossel
* 10 mm Pro-Optic Plossel
* Meade SLR Variable Tele-extender
* Meade #122 2X Telenegative Barlow
* Meade Series 4000 Filter #21 (orange) and #56 (green)
* Pro-Optic Moon Filter
* Celestron #18773 Power Connector (to run the scopes drives from AC if desired)
* A really long Cigarette power adapter (to run the drives from a car or portable battery pack if desired)
* Orion Flexishield – Dew and Sun Shade
* 8″ homemade Solar filter
* 1 extra axis motor (RA)
He can be reached at firstname.lastname@example.org
New Book: Robert Piekiel’s “Collimating Schmidt-Cassegrain Telescopes”
Those with a S.C.T. S.O.S. will find B.B.P.’s (“Barefoot” Bob Piekiel’s) brand new book A.O.K.
We were very fortunate to have Bob as our presenter for last year’s Summer Seminar, where I not only picked up a CD copy of “Celestron: The Early Years” (1800 pages (!) and, BY FAR, the most well-researched astronomy book I’ve ever seen. Anyone wanting to know how modern amateur astronomy was even possible with the advent of modern manufacturing techniques are well-advised to give this digital manuscript a proper spooling up in a computer and see photos and diagrams of what is truly a modern hobby. Telescope-based amateur astronomy was the hobby of only wealth and royalty not 100 years ago) but also picked up a fresh-off-the-press copy of “Testing and Evaluating the Optics of SCTs.” Full-disclosure: I own a mild-mannered Newtonian (a hand-built 6″ form Stu Forster at that) and not a CST, but am just as interested in HOW the equipment we use works as I am WHAT we use it for (we all tend to take modern technology for granted, complaining when a computer crashes but never staring in amazement at the box that such complexity works so reliably at all!). Bob presented on SCTs (in case you missed it, SCT = Schmidt-Cassegrain Telescope) and treated several of us to special one-on-one optics testing of our own scopes with the equipment he brought with him.
The new book is now 20 minutes out of its shipping envelop and so I’ve no thorough review to report, but I have thumbed through it and find the same meticulous attention to detail as his “Testing and Evaluating” book (frankly, it is worth it alone for the many, many pictures of the insides of CSTs, pictures of what you actually see when the collimation is good and, well, not so good (and I’m sure he spent considerable time trying to get the images of CSTs gone bad given how collimated I suspect all of his scopes are)).
There will be a copy of the book available at Darling Hill for anyone’s perusing pleasure. For a few additional pictures and information on how to purchase this new book (and the two previous), check out the cloudynights.com link at:
Averted Vision – Friend or Fovea?
On any given night at Darling Hill, you might hear someone say “OK, now look right where the laser is pointing. Now, look a little to the left or right and the fuzzy patch will stand out a bit more. That’s what we call using averted vision.”
Where the magic happens. From wikipedia.org
Yes, either when viewing with your most important pair of binoculars (the 1 x 6-7 mm pair sitting just under your frontal lobe) or even when using the largest scopes one might find at the observatory, your best chance at seeing something that you might not think is actually there is best performed by not looking right at it.
I thought it finally worth taking a moment to explain what, exactly, is going on in your noggin’ as you’re sloggin’ away at your Deep Sky Object loggin’. You’ll be pleased to know that what’s happening is a remarkable bit of physiology.
The image below shows the density of rods (the cells you see in greyscale with) and cones (those you use for color) in your retina. Your rods only work in black-and-white, so you only see when light is bright or dim (or not at all). Your cones are very densely packed at the fovea (the point on your retina where light from your lens is focused) and fall off rapidly away from it. As a result, your peripheral vision is actually greyscale although you don’t know it (and, when you go to look to where your peripheral vision is seeing something, you’re projecting that object onto your cone-filled fovea, so it’s color again. Go ahead and try, but sit down first in case you make yourself dizzy).
What you don’t see when you see – a map of the density of rods and cones on your retina. The optic disk is the location of your “blind spot.” Your fovea is where your cone (color) vision is best. Your rod peaks (20 degrees to either side or so) are the densest locations of maximum greyscale perception.
When we tell you to “look a little to the right or left of an object,” what we’re doing is watching which way you move your eyes to determine your political leaning (I’ve seen John McMahon’s and Ray Dague’s irises disappear in completely opposite directions doing this).
The other thing that happens is that the light from the fuzzy thing we are telling you to look at is now being projected into the densest part of your rods, those cells best at discriminating light and dark. As a result, you detect detail in an object your cones (because they are responsible for color and, therefore, not nearly as sensitive to light/dark differences) might not have been able to pick up at all.
While the physiology of peripheral vision was not to come for another two millennia, it is reported that Aristotle himself made record of his use of averted vision to observe M41, an open cluster in Canis Major (see THIS LINK for more information and the reference for the original article).
Hope that all sheds a little light on the subject.
Space is the place,
Damian Allis, Ph.D.
Links Used Above (Subject To Web Changes)