This will be a return visit to our Fall 2000 Astro 28A field trip location, to southern Big Sur. We'll explore the history, geology, and of course plenty of astronomy. The centerpiece of this weekend is the graze of the red giant 46 Leonis.
This field astronomy course is built around an unusually beautiful grazing lunar occultation. The bright red giant star 46 Leonis, magnitude 5.4, spectral type M2 and a deep red color, grazes the slender 14% waning cresent moon 28 degrees above the eastern horizon early Sunday morning Oct 10. What is a lunar grazing occultation? Read here. The graze path crosses the southern Big Sur coast and also north of Paso Robles. Our plan is to observe from the San Simeon area if we have off-shore winds that keep the fog away. The profile looks promising at 0.5mi south of the limit. The other good spot is at 1.13 miles south. For my own reference, here are the topozone.com links to the primary site near Lake Naciemiento at 0.5 miles south and 1.13 miles south.
There is another special event for this class. The asteroid Jarmila will occult a 10.8 magnitude star on Saturday night from southern Big Sur. The nominal path passes just 0.2 path widths south of us, but the odds of the occultation being visible for us are good. The event will last only a few seconds, but if we get timings of the event, it will be valuable in helping astronomers determine a precise diameter and shape for this asteroid.
We'll also do some exploring of the principles that determine the structure and evolution of the planets. California is perhaps the best and most unique landscape to illustrate many of these principles. Read more about.... The Geologic Principles of the Inner Planets, Geologic Setting of Southern Big Sur.
This
section of Big Sur is open
to primitive camping on the available dirt roads in the area. and with good
horizons especially south and west; prime for studying the fall Milky Way. The
best campground for doing astronomy on the Big Sur coast is Kirk Creek, 20+
miles north of the graze site. Closer, but likely more light-polluted is Washburn
campground at San Simeon State Park about 6 miles south of the graze site.
If it becomes necessary to drive away from the coast and higher in elevation
to avoid fog for the graze, this campground would be closer, as we'd have to
drive to south of Lake Naciemento. The graze location is about a mile drive
south from here. In the rugged mountains just north of here are numerous faulted
geological features and old gold mines which we can explore. I hope to scout
this location more thoroughly over Labor Day '04. Near here is tiny community
of Gorda Springs
, which has a great little cafe
veranda worth considering for lunch.
Update May '04. I scouted the Big Sur coast and unfortunately, the Arroyo de la Cruz valley is on private property and off limits for us to camp on. Kirk Creek is the best campground on the actual coast of Big Sur. However, it has some major drawbacks as well - it's cramped and always crowded, so we'd have to contend with other campters Coleman lanterns and car headlights. I'm also concerned about fog along the coast for general observing. Even without fog, the crashing surf creates it's own mist and haze which scatters light effectively and makes observing tougher. So, our primary campsite choice is now Ponderosa campground, site of our Astro 28A course (no web page, alas). Ponderosa Campground is at 2,000 ft elevation, over the ridge along Naciemento-Ferguson Rd. It has shade trees of pine and oak, is in a beautiful canyon of sycamore, oak, maple, and has beautiful Fall colors this time of year. The campground will have few people and be quiet and allow us to spread out. The only down side is that it will require a longer drive to the graze - 50 miles to the site south of Lake Nacemiento.
During
non-class time on Saturday or Sunday, there are elephant
seal colonies at Pt. Piedras Blancas, the southern-most extent of redwood
trees at Redwood Gulch,
and the high country reachable from the access road at Cape San Martin. There's
also the beautiful beaches near here like Sand Dollar beach, the beach below
Kirk Creek, and on the inland side there's one of the nicest and least visited
of the California missions - Mission
San Antonio which is near the Fort Hunter-Liggett's center and a short drive
from Ponderosa Campground. I plan to give a lecture on the geology of the inner
planets, and the geology of Big Sur from the pass on Naciemiento Road near camp,
with a dramatic overlook of the coast far below. We'll follow this with enjoying
the afternoon on the beaches and other coastal explorations.