Limiting Magnitude triangles!

I remember these from...high school? Hadn't done much with them, and I won't tonight, but foggy nights are good for organization and theory, I suppose.

Establishing limited magnitude.

A Bad Night of Stargazing Beats a Good Day At Work

Got out tonight about 11:30; clear skies in large chunks but definitely a frustrating evening. Canopus might have been above the horizon but fog banks rendered it pretty invisible. I might have been able to get as close as tau Puppis. Oh well. Could definitely resolve most if not all of Puppis and gamma Velorum to boot, so a good swath of the summer sky extending east towards Hydra and west towards what I presume to have been the vicinity of Caelum and Pictor? Anyway. Praesepe in Cancer was right overhead but nigh-impossible to resolve with my binoculars, Andromeda was fuzzy and indistinct, M79 was utterly elusive although I think I know where to look, Arcturus was hidden in fog over West Cliff though it might be out now...

Still, I suppose it to be a victory that I knew exactly where all of these things should have been; my "global" knowledge seems not to have suffered in a weather-and-sickness-related lapse in stargazing...

[Edit: ooo, and apparently that was Saturn rising in Virgo. Good to know.]

Winter Hexagon

I really should have started with this one if I'd been planning this in any form, since the asterism known as the Winter Hexagon (or, alternately, the Winter Circle, I believe) is the key to the late-fall to early-spring skies.

Fortunately for the part of me that's lazy, the Winter Hexagon is relatively well-known, so people with much better production values throw together jpeg overlays.

I like this site this site Betelgeuse's misspelling aside. (And Saturn's not there at the moment either.

Southern skies in the evening. It's too big to be taken in at once--when Sirius is low in the sky, Capella will be reasonably overhead. Once you get the knack of it, you can start using it to locate some of the smaller constellations in the winter sky! Like those ones I already mentioned! Plus, it's got seven of the twenty brightest stars in the sky, so it sticks out a lot better than Lepus' ears.

One Step Back, One Constellation Forward

What, then, if I have dug too greedily, and too deep towards the southern celestial pole? Why don't we back it up a bit. If I intend to show something more familiar, we'd better get out of constellations you can't see north of Las Vegas or Spain?

Plus I just sort of assume the location of Columba is a given to get one of those kites I keep babbling on about, and that seems unwarranted.

We'll need two reference points, one derived from the other. Orion, and from it, Sirius.



Here we see the constellation at the feet of Orion, nestled right up there underneath Rigel and Saiph, whose existence I had never been able to puzzle out until sometime this fall when I realized that OMG THERE'S A FLUFFY BUNNY THERE. This is Lepus. (wait, let me try that again. Lepus. No, wait, this Lepus, the hare, filling in the spot between the hopefully-familiar (Orion) and the Andrew's-personal-system (I drew a carrot! I see kites in the sky!)

Another picture without all the invisible and therefore meaningless in the field constellation boundaries and all the other lines drawn in is:



Both pictures have their pros and cons. This latter is more uncluttered (look, room for an eye!) but shows way too many little stars that won't ever show up under normal non-magnified viewing conditions. Once you pick up on the shape of Lepus (and I hope you do, it's not as random as this second picture makes it seem) it's hard to un-see.

The second picture also shows its proximity to Sirius, while the first relates it to Columba the dove below it. Now that I look closer, I realize I'm an idiot, and in my haste to make a Srsly joke, I ignored the fact that Sirius is not off-screen in the first pic, but is in fact the bright star below the clever text. Sigh.

Lepus peaks in January and February in the southern sky, about midnight now, but around ten at the end of January and eight at the end of February.

Photos "borrowed" from here and here. I uglied 'em up real good, though.

Update

I've downloaded a paint program, Seashore for OSX, so now I can make lolcat macros about Czech translation some crude star charts indicating the paths I use to navigate the night sky!



So in a nutshell starting out at Sirius and knowing roughly where Columba is, we can construct those two kite shapes, the one of which centered on Columba points down towards Canopus. As earlier stated, you can't try this if you're above Latitude 37°18' north, and that's a theoretical maximum. If only I had readers. *shrugs*

Merry Christmas

Pursuant to the last post, Canopus' window of technical visibility has been creeping earlier and earlier. I chased it again today, setting out as the time crept towards midnight.

The skies were right, and as I walked down Almar towards West Cliff I knew that if I stayed up on the cliffs itself I'd be subject to light pollution from houses on three sides.

I knew a spot, however.



That's me on Christmas Eve of 2007, in a pair of shoes that have been worn out and tossed, a pair of jeans now raggedy, a bag lost in New Orleans in August of 2008, a shirt I don't even know what happened to, and a hat that soldiers on. My feet are in the same place I parked myself tonight, the sea-fig on either side blocking out the light to my sides, as I stared out at Orion and Canis Major and worked my way towards the horizon.

Binocular work is as physical as it is mental; once I'm situated, I'm not sure if the moves I make are grounded in a knowledge of the stars themselves or the knowledge of how far to increment my arms to get me to something I want to see.



The bright star at top left is Sirius; if you see the stars like I do, you can see a diamond shape with the "feet" of the constellation Sirius is in and a star in the constellation below it. In the "eastern" quadrant of the picture is Columba, the dove. See the descending line pointing down from the triangle of stars that forms the head, forming another kite-like shape? Follow that line, adjust a bit to the left...that's Canopus at the bottom. You can trace another line (not in green) back up to that diamond shape I mentioned.

No matter how clear it is, it's always foggy right off the horizon, just west of Carmel Point across the bay. Still, after a quarter hour, I could make out a bright star in the right spot, the same spot as last time. Second-brightest star in the sky, Sol aside. 22.5 miles farther south, and Canopus never breaks the horizon, and I get it twice in a month? I spotted it maybe a degree above the horizon, and, to add the cherry to my Christmas cake, I swear I caught an averted glimpse of it with the naked eye as I stowed my binoculars and headed up the stairs.

Merry Christmas to all.

Can it be?

CHDKable camera, tripod en route from Vermont (early Christmas presents). I believe I have spotted Canopus nineteen minutes of latitude (22.5 miles) south of where it is impossible to see. Monterey Peninsula stops in time, and the fog held off for at least the forty miles across the bay to allow me to make it out--I used beta and eta Columbae as pointers.

If I can figure out the weather and the mechanics (should be in the same position four minutes earlier every night) I might even get a picture. I wouldn't hold my breath, but I am fairly elated for three in the morning.

(Just watch me find out tomorrow it was a boat or something. Seemed too steady for that; I got a good fifteen minutes of observing in.)

[Edit: I was going to teach myself how to calculate star transit times, but Wolfram Alpha seems to know how to do that. What I saw was in the right portion of the sky at the right time...]

Stargazing:

The stars you can see at night depend on the time of year and the time of night, of course, but also on your latitude. Burlington's at about 44°28' north, about halfway between the equator and the North pole. As you go south, you can see things closer and closer to the south celestial pole, within certain defineable limits.

Santa Cruz is at 36°59'--I'd been able to figure out it's farther south than what I was used to but I hadn't known the details until this morning.

Canopus, the second-brightest star in the north sky is theoretically visible from lat. 37°18', The existence of Monterey and the hills behind this probably wash it out, or did last night--I figured out I could get painfully close. I guess I should check out other locales (up the coast) which leave the south view as free as possible and check on some celestial mechanics.

On the plus side, I've never gotten better views of Canis Major, and I've been figuring out some of the smaller constellations around it. (Lepus and Columba last night).