Astro 25 - "Field Astronomy in the California Mountains"

Apr 5-7, 2019 - Spring '19 At Sequoia National Park

Post-Trip Pictures

Apr 5-7, 2019

PowerPoint and map packet

This offering of Astro 25 is built around a particularly beautiful event - the Saturday evening graze of a 7th magnitude star against the Earth-lit southern polar region of the thin crescent moon. We'll be watching and video recording with GPS time-stamps the disappearances and reappearances of the star against the dark mountains and valleys on the edge of the moon, for a period of about 3 minutes at the end of twilight on Saturday evening. The path where multiple grazing events can be seen is only ~2 miles wide, and this path crosses the southern edge of Sequoia National Park in the Sierra, passing through the little town of Three Rivers in the foothills, which offers a good place to set up stations to record this graze. Precise timings of lunar grazes is the most accurate means by which we can add new data to the orbital behavior of the moon. These can also reveal new binary stars. And, they're just beautiful to watch!

During the day on Saturday we'll drive into Sequoia National Park, do some hiking to offer points for my "micro-lectures" on planetary processes. We'll enjoy the Giant Sequoias and their prospects under coming climate change. The hiking will be no more than a few miles. Sunday morning after breakfast we'll do a hike up Marble Canyon Falls. Friday night, and Saturday night after dinner and after returning to camp from the graze, we'll set up scopes and examine the star clusters and star forming regions of the early Spring sky, study galaxies rising in the east of the Virgo Cluster of Galaxies, and the Coma Cluster of Galaxies.

Why Sequoia National Park? ... The Saturday Evening Grazing Lunar Occultation of X110502 !

At 8:09pm PDT, this medium bright star will just "graze" the rugged dark south pole of the moon, disappearing and reappearing many times as it passes through the lunar valleys and mountains. They're very beautiful to watch, and valuable science too. The star is magnitude 7.6, K0 spectral type. Graze is 12s of the 3% waxing moon, sitting 7 degrees above the astronomical horizon, with the sun at -11 degrees (a dim twilight still silhouetting the foothills. The 7 degrees altitude is a challenge. Fortunately, the best place on the profile, promising 10 D's and R's, is accessible from the top of a ridge from which the horizon beneath the moon is 6 degrees, so the moon will sit 2 diameters above the top of the hill it sets over. The moon moves its own diameter every minute, so 2 minutes after central graze the center of the moon should touch the top of the mountain. 2 minutes after central graze is when the star emerges and hits the tiny trailing hill on the moon. But being on the southern edge of the moon, which will in fact be the left edge, the altitude at that point should be the ~same as the center of the moon. Refraction will aid a bit, but it'll be tight but do-able to see the final 3 events before moonset. Bring your DSLR cameras and long lenses to get some nice pictures of the adventure!

Graze Predictions

Campgrounds

We've got reservations at Potwisha Campground , which we used on a prior Astro 28 course. I've now got reservations for campsites #14, 15, and 17 for the weekend of Apr 5-7, at Potwisha Campground. Nominally, those sites can hold up to 18 people. We'll see how enrollment goes as we get closer. I might try to get another site, or we'll just negotiate with the ranger for getting us all, if there's a lot of people.

Schedule

Saturday Mar 16 at 9am -12 noon: On campus room 705.
This is our Pre-trip meeting. PLEASE plan to be there! Here we will have some business to take care of:
* Sign liability waivers (no one may come on the trip who has not signed the liability waiver - Cabrillo rule!),
* Give slide show on the course, explain lunar grazing occultations.
* Discuss meals and payment. Generally students opt to have me cook for them. I'm a good cook! We'll have French Crepes Saturday morning, pan fried eggs and veges on Sunday, Asian Rice a'la Nolthenius on Saturday evening, and a pasta dinner on Friday evening.
* Make friends with your fellow classmates, and give you time to arrange car pools. The Cabrilllo van will be chock-full of my volunteer help and all the kitchen and group camping gear and the telescopes gear as well, so we won't be able to haul students, alas. However we'll be able to take a few on the day trip into Sequoia Natonal Park on Saturday.
* Give a short Planetarium show to introduce you to the sky.
* Hand out map packets to all students, so you'll know how to get to our campsites, and where we plan to hike

Friday Apr 5

Meet at Potwisha Campground. We won't be caravann'ing from campus. Use your map packet I distributed at the pre-trip meeting, and/or smart phones to get to the campground. Look for the white Cabrillo van (labelled on the van side) or a red van (Kirk B's van - an astro club volunteer). I realize you may have Friday commitments and so am not going to be too strict about when you arrive. however, we'll fix dinner as soon as sunset, so we can be at the telescopes soon after dark. It's about a 4-4.5 hr drive from Aptos.

After dinner - we'll be at the telescopes with plenty of micro-lectures and viewing on star formation, planet formation, the structure of the Milky Way in our spring sky, and more cool topics. This may last until midnight! Kirk usually does stay out till even later (but he's a volunteer; we'll see how that goes). If cloudy, we'll be around the campfire (bring you beach folding chairs!!).

Saturday Apr 6

8:00am - I'll be up early starting to fix our more memorable meal - a breakfast of French Crepes.

10:00am - start our 7.4 mile round-trip hike (1600 ft of climbing) along the creek up to Marble Falls, with micro-lectures along the way on planetary processes and the origins of the chemical elements that make the plants, on star and planet formation. OR... drive into the National Park and we'll stop at a few spots for micro-lectures on how climate is affecting mountain ecosystems, especially the Giant Sequoias.

4pm - Be back from our hike. I could probably use a bit of help for making dinner. Otherwise, some rest time for you while I get dinner cooked, ready by 5pm

Dinner Served 5pm: Early before graze, is our decision. We'll want to be ready to depart for our graze site 10 miles or so back down The Generals Hwy to Three Rivers at 6:15pm

6:00pm - Be ready to pack a jacket and yourselves quickly. I can take at least 6 people in the van, the rest will need to carpool. Plan to leave camp at 6:15pm driving a few miles back down the canyon road to our graze site near Three Rivers, maps will be in our map packet and you can of course play "follow the leader" with the Cabrillo van. I plan to set up two video recording stations. We'll want to be done setting up equpment at least a half hour before the graze, which is at 8:00pm. It only lasts a few minutes.

9:30pm - midnight - Afterwards, we'll look at our data quickly, take some victory photos of our group, and head back to the campground where I'll fix dinner while you're entertained at the telescopes by our volunteers. Our micro-lectures will be on Galaxies, cosmology, quasars, black holes, the origin of the universe, and other Cosmic subjects! Some of our hardy astro people will be up after midnight, most likely, but we'll officially wind things down before then. If it's cloudy (I hope not!), we'll have campfire lectures on these subjects.

Sunday Apr 7

7:30am - I'll be up early to start on breakfast. I might (if my knee allows) go for a short jog on the Marble Falls trail first.

8:40am - We should be eating and finishing up and doing clean-up after that.

9:30am - We'll review our video tapes of the graze last night and make initial conclusions about any lunar orbit, stellar astrometry, or mountain topography shifts. Then, followed by a solar viewing session at the telescope, Discussion of the solar magnetic cycle, effects on Earth and climate, where we are in the cycle, and other topics. We might skip solar viewing, since there are NO sunspots and it's just a featureless disk of brightness, as of one day before our trip . It's a very deep solar minimum we're going through. Most days of 2018 and 2019 have had NO sunspots at all.

10:30am - Followed by a short hike along the river for Native American pictographs exploration, and our last lectures. Hospital Rock is just 2.4 miles further up the river from the campground, and is a beautiful Native American pictograph site

Noon - at the latest - Hand out the take-home final exams. Instructions on how to get those done, and sent back (or walked back) to the instructor in the envelope I keep outside my office door room 706a. I need your hard-copy to grade, so don't send me email files! Pack up your stuff and say our good byes, head off to enjoy the rest of your day or drive back to Aptos. We should be home by sunset.

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Updates:

Wed morning Apr 3 - 12:13am As of Wed morning, the weather forecast has improved. The wet weather coming through Central California on Friday looks to have the front pass by Friday late, and we should awake Saturday to dry weather and decent chances for clear skies for the graze on Saturday night. We'll stick with our Plan A - staying with Potwisha Campground at Sequoia. Bring your rain ponchos and rain fly for your Friday night camping. I'll have a canopy 8' x 8' which should at least cover the kitchen gear and students standing next to it for our Friday dinner. I'm very hopeful that we won't have to worry about rain by Saturday morning and our French Crepes breakfast.

Thur afternoon. 3pm - There's an interesting Native American historic site right next to our campground, down on the Kaweah River. We'll plan to explore this on Sunday morning.

Here's the latest weather forecast for Potwisha Campground (elevation 2,200 ft.)

Bring firewood in case we can't do any telescope viewing, so we can enjoy the warmth and talk astronomy around the campfire.