Back to the Future - Asteroid Occultation and Trail Run to Caliente Peak Redux

Oct 21/22, 2015

In honor of "Back to the Future" day - Oct 21, 2015 (when Marty McFly arrived from 1985 in Part II), it seemed the stars aligned to motivate me to do a return to Carrizo Plain National Monument. For the second time in less than a week, there was a high-rank asteroid occultation passing through my favorite part of the Monument, and my Caliente Peak trail run of last Friday was so soul-satisfying that I felt I just had to do it again as soon as possible. It's a 17 mile round trip run, with well over 2,000 feet of climbing along the way, and I admit I wasn't fully recovered from last Friday's run. To repeat it in just 5 days for this senior citizen seemed to be asking a lot. But, I'd gotten back to some easy runs already, and I felt OK finishing up a 25 mile ride / 1500 yd swim / 4 mile run on this fine Wednesday Oct 21, and I decided to go for it. The asteroid occultation was by Eukrate, and was nicely higher rank than the Oenone event last Friday, and with Chuck M. in Santa Barbara signed on, we had the possibility of getting 4 points nailed on this rock, allowing a comparison of this deduced profile shape to earlier data.

I rode home from my swim workout, spent an hour packing some food, filling my Camelbak for the run, preparing findercharts and a "planning page" for the asteroid, then drove to Cabrillo and packed the scope and video timing gear, and was on the road by 10pm. I arrived in Carrizo Plain at 2am, setting up near Selby Ranch, which was a tad closer to the predicted centerline than the familiar campsite up on Caliente Ridge Rd by a kilometer or so, and gave me official odds of 81% of being in the path (vs. 80% at the campsite). The weather was dry and clear, and the ground had dried as well - no toads to dodge on the Selby Ranch dirt road this time. Again, it seemed I had the entire National Monument to myself. It was quiet, a gentle breeze, and all around invigoratingly excellent.

My new procedure for asteroid charts is to use the large UCAC4 catalog linked to C2A, and putting it in "horizon" mode, and with a FOV marker matching the Watec 910hx chip. I pumped up the star sizes, and color inverted the output charts to better see them in the dim red light of my headlamp. However, one glitch happened, when the power to the videocamera seemed to quit. The gelcell battery was OK, so I hoped it was a fuse inside the 12V male connector. Yes it was, and I found a replacement and was back in business in just a couple minutes. I settled on an integration time of 8x (or 1/8 second) since on 4x I couldn't see the target. In hindsight, I should have stayed with the 4x and looked harder. As the 12.1 asteroid merged with the 11.5 target star, they occupied fewer pixels, and by the event time, were quite easily seen at 8x. So, I sacrificed a bit of time resolution at that integration period, but not a real issue given there were only two chords for this event.

Getting the faint 11th magnitude star on target was fairly easily done.

Victory is sweet! The data looked excellent on the LCD monitor, with a ~5 second occultation.

A winter Milky Way shot with Orion, before packing up. 30sec in the 10mm fisheye at high ISO

I then drove the mile or so up to the campsite on Caliente Ridge Rd to try to get a couple hours sleep before dawn. Venus and Jupiter were just rising in Leo, with faint Mars right below Jupiter if you look hard. The light pollution dome of LA is at middle, and Bakersfield on the left. Fisheye again.

I got to sleep at 4:30am, and got up to prep for my trail run at 7am. For about 15 minutes before nodding off, I enjoyed the dark skies and watched a few piece of Halley's Comet burn through the atmosphere above Carrizo Plain, as the Orionid Meteor Shower was peaking this morning.

I love the aetherial curves of the hills and mountains of Carrizo Plain in the pre-dawn skies. At this site, at which I've camped so many times, I nearly always get up before dawn to admire the beauty of it

The green flash (that little speck inside the huge red "H-Bomb" glow), as the first spot of sunlight appears. Think of the sun as 3 suns: red, green, and blue. The red sun refracts the least, so rises the latest. The blue sun is scattered out by so much atmosphere (that's why the sky is blue!), leaving the green sun remaining, and the sun is brightest in green light anyway. The 3 suns are almost but not quite perfectly aligned, so the effect only lasts for a second or two.

A moment later, I see a kind of "Bailey's Beads" from the ragged eclipsing edge of The Carrizo's Temblor Range, and these provide more green color at the moment of first sun's rays.

I roll up my bedding, then a short 2 mile drive to the ridge, at about 4,000 ft elevation along a sketchy dirt road after last Friday's rains. Breakfast was simple; a hard boiled egg and a banana.

I'm looking forward to another long solo run.

At 7:45am I'm ready to head out.

Looking south, with Mt Abel on the far right, and haze in the Central Valley in far center.

My footprints from 5 days ago. Thankfully the ground was dry enough now that I wasn't carrying along an extra pound of mud per footfall this time.

There is a timeless quality to this long trail that invites introspection. It hasn't changed much in 50 years. The fact that no one (apparently) comes here except in the Spring wildflower season, accentuates this. I loved the solitude, and every step I took farther from my car, which was the only hint of civilization for a hundred square miles, was another step back towards that timelessness. There is an old abandoned ranch site halfway to the peak, slowly being resorbed by Nature. Pretense gone, blunt and real, I find it calming; going back to the roots.

At the ranch site I take a short break, imagining when this old lounge chair had something to it besides rusty metal.

Streching the hamstrings means less resistance for the hip flexors and psoas (my weak link) on the return swing of the leg.

...onward

Only way I could do this run...

...was to take frequent brief photo-breaks. This Jerusalem Cricket was what we used to call Potato bugs when I was young.

The Temblor Range on the horizon defines the eastern boundary of Carrizo Plain...

...and if you look close beneath it you'll see the long eroded scarp defining the San Andreas Fault

"Snakes. Why did it have to be...snakes?" A friend thought I was a bit reckless to be in rough territory on my own so far from help... "what if something happens?" But I waved it off - I love being on my own so far from help! But it did occur to me that if I stepped on a rattlesnake (as I almost did on a run at Pinnacles National Park a few years ago), 8 miles from my car and then 50 miles from services... I'd really have to "science the hell" out of that situation...

...I decided to look carefully a few strides ahead as often as I could

The trail followed the ridge nearly always, giving you a series of 10 hills and mountains, the last being the highest. At the mountaintops, there were grand vistas

I was starting to run low on fuel. For this run, I brought more than last Satuday, starting with this fruit thing I got at some race aid station.

A fossil clam on the trail; this range was thrust up from shallow ocean basins around the Oligocene and Miocene periods.

This sandstone shows cross-cut shells of ancient ocean-dwelling creatures

Caliente Peak finally comes into view

A local resident

On top at last. The rugged landscape south of Caliente Peak, where the trail ends

The trail originally was a jeep trail to service this old WWII lookout, manned by observers looking for Japanese bombers coming in from the west to attack the rich oil fields of Taft, just over the Temblor Range.

Around 10 years ago, the structure finally collapsed

Signing the summit register

Only 4 peak-baggers in the past 6 months, and half of them are me, this week.

No toads this week, but this baby horny toad was adorable!

a new friend

Heading back...

Pronghorn antelope track. And by the way these tracks' toes were dug into the dirt farther ahead, it was running.

Maybe this is why; mountain lion tracks.

A quarter mile further, and I see claw marks in the dirt, and signs of a big scuffle, and signs of being dragged off into the bushes. Recent - as in, I don't remember seeing this 2 hrs before, when I ran by here. No more pronghorn tracks beyond this. Hmmm.

So, OK, stepping on a rattler, OR getting taken down by a mountain lion... Both of those would be significant difficulties. But then, I don't look like a pronghorn antelope

...except for my white "doo'rag" headgear. And I don't look injured (even if a pronghorn could outrun me in a flash)...maybe except for my blood-red shirt? Hmm. I decided to pick up a sturdy stick and glance behind me for the next couple of miles.

Completed! 17 miles and still smiling, thanks to a couple of ibuprofen's!

Driving back down, rounding the corner is a great view of Selby Ranch remains. Drying climate drove out the few farmers from this area long before it was turned to a National Monument.My asteroid observation site was just beyond the last of the dirt road at upper left.

I felt a certain sadness, leaving this place, and driving back north, eventually to more populated environs. Time no longer stood still. I put on Prof. E.O. Wilson's "The Social Conquest of Earth" - an audiobook. Perhaps it would help me understand my own species and its often lamentable choices.

The Eukrate Occultation: Data and Reduction (wikipedia page summarizing what we know about Eukrate at this time)

Coordinates are from the IOTA-VTI GPS system, recorded on miniDV.
Long: 119d 50.1468'
Lat: 35d 07.9546'
Track -51.3km = 51.3km north of centerline
Elevation: 2353 ft
Datum: WGS 84
Almanac updated before data begun, UTC correct. 11 satellites HDOP: 0.9

I've captured the .avi file off the camcorder, and reductions and graphs follow. Here is the .avi file (350Meg so be careful)

Occular was downloaded, installed but required installing outside of c:\programs(x86). LiMovie reductions below. The Watec 910hx was set on AGC=off, gamma=1.0, integration=8x (= 4 frames or ~1/8 sec time resolution).

LiMovie settings and image of the field of view. The target is upper left, and the comparison star and the tracking star are the same - the star at lower right. The photometry/tracking radii are all set to default, which was 3, 5 pixels for inner/outer photometry. Target, comparison, tracking all set to 'drift'. I verified that the target circle did not waver during the time of the occultation; it seemed to be fine tracking the fainter asteroid light, and the R happened within the inner circle.

PSF Track+Photometry .csv

PSF Track .csv

noPSF+Linked .csv (this is the proper one for best photometry)

"Very interesting!". Two things are surprising - the drop to the middle of the occulted brightness was about 1.53 magnitudes, not the 1.1 magnitudes predicted. This is probably spectral sensitivity and color differences in the star/asteroid. The second interesting thing is the gradual drop halfway through the occulted period. One would expect it to be flat, or perhaps a 'step' if a close binary star. Is this diffraction? Hard to believe it's stellar diameter. If it were a red giant it would have to be very distant to be 11th magnitude, and hence still small. And a nearby red dwarf would also be very small. Hard to believe mainly because it lasts so long. The main occultation points were very sharp, by contrast. There was no cloud, no haze, no dew on the corrector plate (I checked) the sky was perfect, as the sunrise images in this story show.

Was it some sort of excursion in the comparison star? No, that looks ruled out too, based on the (pink) comparison star light curve.

Looking at more of the before/after, there's a hint that the blended image was a tad fainter for a few seconds after vs. before the occultation. But not the ~120 counts shown inside the occultation itself. I suppose with noise, it could still be best interpretted as a binary star. However, the word is that Chuck M's record doesn't show this non-constant bottom.

 

Both comparison and target look well-behaved for the minute before and minute after the event.

 

Gaussian fit to the PSF stellar profile of the target. Looks good. Nothing pathological here either.

After some more experimenting and help from Tony G and Brad T, I have better photometry data to show. I linked the tracking on the asteroid to the tracking star, used wider circles, and did not use the PSF option, which some find doesn't track as well as the simple aperture method. The curves now look good! The .csv lightcurve file is here

The LiMovie parameters here. Again, the tracking and comparison star are the same.

The light curve now shows no duplicity, and looks less noisy. However, there is a curious increase in brightness just past halfway. I have heard that Chuck M's light curve shows the same thing, from a rather different track. Noise? Coincidence? ... ALIEN drill hole??

Zoomed in. No drift in the occulted magnitude, except for increased noise or something for a second just past halfway.

Results of the analysis within Occular. Frames averaged=1.

Same, zoomed in.

However, I need to block avg the frames to account for the integration of the camera. Doing that then gives "num pts=4" and offset=1 gives the proper avg for the clearly blocked points at the occ D. Below is the block avg'd version with analysis and final report. Tony George did an independent analysis of my recording and gets the same timings using R-OTE, so this final analysis is the one I'm going with. The report form from Occular is below, and after correcting those timings, the IOTA report was file on Oct 27, 2015. Brad T has produced the sky-plane profile of the asteroid, based on the 3 successful tracks for this event.

Block avg'd 4 frames, timings shown with statistical curves.

Zoomed in on the occultation itself.

Very well determined D and R

One thing I commented on, is that the nominal Occular accuracy of the timings is given as 0.012 seconds. However, the block resolution of the time was .125 seconds or 10 times larger, so this accuracy is far too "good" to be believable. I did report it this way on the IOTA report anyway.