Sunday, May 07, 2017

 

Issue 540: Get Thee to a Dark Site II


Last ish we got you a dark site, or at least gave a few pointers as to how you and your fellow astronomy club members could find and keep one. This time, we’re going to talk about using that site.

And you know you want to use it. Sure, in this day of electronic cameras and computer processing you can take pretty good pictures from the backyard, but you’ll always get better results under dark skies. Visual observer? As I said last week, the galaxies of spring cry out for the darkest skies possible.

There is no doubt about one thing, spring weather in the USA, and especially east of the Mississippi, can be capricious. Before talking about what you bring to your club’s observing field and what you do there, maybe we should discuss “whether.”

Obviously, if you’ve got beautiful blue skies and the forecast is for more, a dark site trip is a natural. But what if the sky is unsettled and the weather forecasts ambiguous? Back in the day, back when I was more sanguine about hard-core observing, back when I lived downtown and couldn’t observe anything from my backyard, I had a rule, “If it ain’t raining, head to the dark site.”

That stood me in good stead for years, and resulted in me seeing far more than I would have if I’d let a few clouds scare me off. Most of the time—though certainly not all of the time—I at least saw something at the club site in return for an hour’s journey into the west. I would sometimes wimp-out observing plan and gear-wise, though. If the sky really did look doubtful, I’d tend to change my plans from “astrophotography” to “visual,” and the telescope from my C11 to my 5-inch ETX Maksutov Cassegrain, Charity Hope Valentine.  Anyway, I always found that even if I was mostly skunked, I had a better out on the observing field than I would have had sitting at home watching television.

Let’s say, you’ve got a night that looks to be uncompromisingly good, though. What do you load into your vehicle? The simple answer is “everything you need, nothing you don’t.” Certainly you want all the gear you require to allow you to execute whatever your observing plan is, but there are things you’d take to a multi-night star party that you will likely want to leave at home for a club site run. Remember, you’re going to have to pack all that stuff back into your car at the end of the evening and possibly unload it at home.

What NOT to Bring to a Dark Site…

Observing table

You may actually need an observing table depending on your vehicle and what you are doing, but maybe you can back off from a big camp table to a TV tray. If I am doing visual observing, a table just large enough for an eyepiece box and maybe a star atlas is more than enough. Imaging? I’ll need something to put the laptop computer on, but not anything more than that.

When I switched vehicles from a sedan (a Camry) to a truck/SUV (4Runner), I eliminated observing tables altogether, operating out of the back of the 4Runner, tailgating it as it were, which is the best of all worlds—I even have AC power available there from the truck’s built in inverter and auxiliary battery.

Computer 

This is a maybe/maybe not thing. Even if you are doing imaging, you may be able to eliminate the laptop. Using a standalone auto-guider and a digital single lens reflex (saving images on the camera’s memory card) can allow that. By saying “ixnay” to the laptop, you can also leave one large battery at home (a laptop’s internal battery will rarely last an entire observing run), the above mentioned table, cables, mouse, mousepad, etc., etc., etc. Yes, it’s nice to have a computerized star atlas like Stellarium, but in the interests of simplicity, sometimes I don’t mind getting reacquainted with Sky Atlas 2000 or Uranometria. Just can't go back to that? SkySafari running on a tablet is a good compromise.

Stuff you always bring and never use 

You tend to throw a pair of binoculars in the car, but never/rarely use them? Leave them at home. The same goes for stuff like extra flashlights, a second box of eyepieces, radios, ice-chests, etc. All that junk is nice at a big star party, but you are not going to be at the dark site long enough to feel the need for this stuff.

A telescope that is just too much

Small can be beautiful...
We all want to maximize our observing experience, but if a telescope is so large and/or complex, that by the time you get it assembled and working it’s time to go home, leave it at home. Give me a freaking C8 for dark site use not a C11 or (horrors) C14. When all your buddies are packed up and ready to hit the road and you still don’t have the scope off its mount, I think you’ll begin to believe that sacrificing some aperture and/or features might not be such a bad idea.

Things that will annoy your fellow observers and possibly the landowner
  
Radios blasting your particular preference in music and green laser pointers that make the sky look like something out of Return of the Jedi have no more place at the club dark site than they do at a big, organized star party.

What to Bring

A Telescope 

Sure, you know to pack the telescope, but make sure you pack all of it. One night, one cloudy night, when it wasn’t raining, nevertheless, I headed to the dark site with my C11. As soon as I arrived onsite, almost magically the clouds began to scurry off and I began assembling my big scope. Yes, as above, it was really too much for a short dark site run, but I was younger, stronger, and dumber then.

I had just got the NexStar 11 GPS on her tripod when I had a vision. Of the telescope’s hand control sitting on the dining room table of Chaos Manor South. And that was just where I’d left it. What to do? There wasn’t anything to do. I packed up and went home. I was just thankful I wasn’t at a star party 400 miles away.  

In the interests of this sort of thing not happening to you, it’s a good idea to have a checklist.  If you know an item is necessary, put it on the list and don’t check it off till it is packed in the car.

Power

A telescope that doesn't need batteries can be nice sometimes...
Some lucky folks have AC power available at the club site, but that is rare. Be prepared to operate off batteries all night. So, ensure your batteries are fully charged beforehand. Don’t just assume they are. What sort of batteries? I favor the ubiquitous 17ah jump start battery packs. Not only do they have enough juice to power most scopes and accessories all night, they usually have built in lights which are handy when you are packing up at the end of the evening. Yes, don’t take too much stuff, but don’t scrimp on batteries. I always take one for the (goto) scope, one for the dew heaters, and one for the laptop.

Dew Heaters

At home, in my backyard, I can often get by without a dew heater system on my SCTs and refractors. My house and neighboring houses and trees shield much of the heat sucking sky from the view of my scope, acting as giant dew shields. On an open field out in the country? Uh-uh. Even if your area is drier than my Gulf Coast stomping grounds, you’ll need something to keep dew off.

Dew prevention is a subject for an entire article, but I can offer some basic guidance here: use heater strips on objective or corrector. If all you have is a dew-zapper gun—a 12 vdc hair drier cum window defroster—you will soon lose the battle against dew. A zapper can be sufficient for the secondary mirror of a Newtonian reflector, however.

Observing Chair

You’d think this would be something I’d tell you to leave at home, but it isn’t. Even for a relatively short visual observing run, being comfortable means you will see a lot more. Bring the chair along.

Accessories

Use that checklist to make sure you bring the vitals:  eyepieces, star diagonals, star charts (or a smart phone or tablet), red flashlights, etc. Don’t overdo. I restrict myself to one eyepiece case and one accessory box (a large Plano tacklebox).

Insect Repellent

"If it ain't raining." Sometimes you eat the bear, and sometimes...
Whether “just” a can of Deep Woods Off, or a Thermacell, don’t even think about heading to the dark site without bug zappers except in the very depths of winter.

A Coat/Jacket

“But Uncle Rod, it’s only gonna get down to the lower 70s.” Bring a coat or sweater or sweatshirt anyway. You will never be colder than when standing nearly stock still at a telescope under an open sky. Let it get to the mid-60s and you will begin to shiver and will throw in the towel unless you are prepared.

Cell phone

Don’t just always bring your cell phone with you as we insisted last time, make sure it is fully charged before leaving home. Taking a DC charger to the site might not be a bad idea either.

A Few Amenities

You won’t be out there that long, so don’t pack too much additional stuff, but certainly a few bottles of water and maybe even a couple of snack items is “reasonable.”

Setting Up

It’s your dark site, set up anywhere you like, right? Sure. But some places are better than others. If there’s been a recent rain, you’ll be better off on your field's high ground if it has any. You probably don’t want to be on a slope, however; telescopes are happiest on level ground. One other thing? Togetherness is fine. You want to be close to your buddies so you can share observations, chat, etc. However, if you’ve only got a few people at the site there’s no need to set up 3-feet from the next scope. Spread out and give each other some room.

Observing

You observe the way your normally observe at home or at a star party. What I’m really talking about here is observing rules. Your club probably needs to come up with a few. You want to prohibit white light and probably green lasers. But you don’t want to keep adding so many rules that people feel stifled. And be aware that at a club site with two or three people on the field, all those beloved rules formulated at that marathon club business meeting are likely gonna be observed in casual fashion at best.

For example? You wouldn’t dare fire up your vehicle and drive off a star party field at midnight, but at the old dark site with a few people around? It’s likely to be, “Had a great night Wilbur! See you next time, Hiram! Gotta head on home.” If everybody’s observing visually they can shield their eyes while you motor off. If someone’s in the middle of an astrographic exposure, wait until they are done. Just use common sense—and the same goes regarding any rules you and your mates think up.

Packing Up

The Moon is rising, or it’s just late, or it’s just you and your friends’ usual turns-into-a-pumpkin time. What about tear-down of the equipment? If, as above, you have to leave earlier than your pals, you’ll need to pack by red light (one of those red LED head-lights on a head-band is good if you keep it pointed at the ground).

You'll soon tire of using a dew-zapper gun...
Anyway, when the time comes, disassemble your scope, taking care that everything gets back into the vehicle. I tend to be a little less than scrupulous about putting every widget back in its proper place in the cases; I just shovel it all into the car so as not to delay my friends, and worry about sorting everything out the next morning (I can leave all my stuff in my car overnight thanks to a safe and secure neighborhood).

Once everything is back in the car, go over your area carefully with a white light to make sure nothing got dropped and that you’re not leaving any trash behind. Help your fellows out with the same thing. Then—well, you’re off for home (or perhaps your favorite late night bar out in the boondocks).

You’re off if everybody is ready to go, that is. One rule our club has made and that we observe scrupulously is, “Nobody leaves till everybody leaves.” Obviously that doesn’t apply to someone who has to go early for whatever reason. It just means those of us left at the end of the night linger on till the last person has their gear packed. That’s good for security’s sake, but even if, like us, you have a very safe dark site it’s still a good rule to live by. What if the last person standing has trouble getting their vehicle started?

Then, just say your goodbyes, “Great time, y’all! See you next time.” If you did everything right, and your club has the “right” site, believe me, you’ll hardly be able to wait for next time. 

Comments:
Nice article, as usual, Rod. I have to smile at your obvious, southern observer bias, though, regarding these past two installments. Snakes? Insects in all but the depth of winter? Security? Shivering at temps in the mid-60s?

Up here near the Canadian border you only have to deal with ravenous insects for 2-3 months each years, but DO have to be prepared for cold (serious, sub-zero cold) for 4-5 months. If the night is clear, it's almost always COLD.

ZERO cell phone reception is common, but so is the abundance of public, DARK sky sites (gravel pits, clear cuts, lake shores), as the vast majority of the landscape is in public ownership (state and national forests, etc.).

America is a big place, and it is fun to compare the regional challenges facing observers.
 
Gotta tell you, Gordon, I'll take my bugs and snakes over your C-O-L-D any day. Why, I nearly froze one late summer night at the Northwoods Star Party (where I was a speaker). LOL
 
Wow Rod the US truly is a different country! I'm not sure we're allowed cars that big here in England. And you're suggesting I drive to Wales for a night out?

Love your articles, keep 'em coming!

Phil, Salisbury, UK.
 
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