Astro 28C: Field Astronomy at Big Sur

October 12-14, 2001


     This class is a ½ unit course suitable for transfer to CSU as a science elective. I'll give the roster to our division secretary who will enter the names/ID's into the computer. You'll wait 24 hours for this to happen, then be eligible to register for the class the usual way - through Hawk Talk or on-line. You can drop the class and get a refund on your campground fee until Sept. 20. After that there are no refunds. We need have time to fill in slots for drops. 

   The $15 camp fee covers the campground overnight charge for two nights and with any money left over I'll buy fixings for French toast breakfasts Saturday and Sunday morning!

General Information

     We're going to the Big Sur coast! This will be a fun and educational course which will get you hip-deep in astronomy. This course is built around a unique astronomical event; The northern limb of the waning cresent moon will graze the hot main sequence star SAO 99202 at 5:30am Saturday morning Oct 13. The graze limit crosses Hwy 1 at Andrew Molera State Park, (but we’ll be camping at Kirk Creek further south). This star is a relatively young star, about twice the mass of the sun, and glows at a temperature of over 10,000 degrees Kelvin. It's relatively bright, at magnitude 7.7. Its blue-white color will contrast with the moon in our larger telescopes. We will watch as the star is seen to slowly move along the dark edge of the moon, disappearing and reappearing as it passes behind the mountains and valleys seen in silhouette. Such an event is called a "grazing occultation". Our goal will be to record the exact moments that the star disappears and reappears from several locations or "stations"'. These times provide the most precise way astronomers have of charting the changing orbit of the moon (the moon's orbit slowly changes due to tidal friction and gravitational effects from the other planets). The geometry of these events requires that the observers be within a very narrow band (about a mile wide) which traces across the earth as the earth and moon move. The path for the graze crosses over the summit range of the Big Sur Mountains, at Chews Ridge, all the way up Carmel Valley Rd. This site is renowned for it's incredible skies and astronomical seeing conditions and was chosen as the site for the Monterey Institute for Astronomy's 36" telescope. We'll camp the first night at China Camp just over Chews Ridge, so it'll be a short drive to the graze site in the early morning.

   Of course, we'll also have our our scopes to show you the deep sky wonders - last views of the nebulae and star clusters of the summer Milky Way, and the Andromeda Galaxy... Our site will be far from city lights and very dark all night long.

     The Cabrillo Astronomy Club will be along to help show you the sky, help get you rookies into graze ship-shape, and generally enliven the festivities.


Thursday Oct 11; 5-~8 pm:  On-campus general orientation, planning food, carpooling. Lecture on grazing occultations, origin of the moon and planets in planetarium (Room 706). Planetarium and slide session.

Friday Oct 12

   The class officially begins Friday evening. However, it is a roughly 2 hour drive to our campsite. I and most of the astronomy club will be caravaning down to the site, leaving from the observatory around 2pm Friday. If you have to leave later, we'll make sure you have maps to guide you to our site. After a group meal, we'll break out the scopes for some


Saturday Oct 13

      The graze occurs at 5:30am and lasts just a few minutes. We'll need to be up an hour ahead of time to drive to the site and set up a few graze observing stations. That means we leave camp at 4:30am. Yikes! We don't have enough scopes for everyone to watch, but students will be grouped around available scopes so everyone can see the moon and star at least before and after the graze, and during the graze you'll need to have just one chosen observer. During the day you're free to explore. Interesting ocean contact faults line the coast here. We’ll enjoy the sand and surf and talk about about the geologic history of the Big Sur mountains.  Gorda has a store, a nice outdoor café, and is close to Sand Dollar beach. Camping here will set us up for a nice drive home along the heart of the Big Sur coastline and perhaps a farewell lunch at Nepenthe .


* Unregistered people: Many people ask whether they can bring along a friend, "significant other", or kids/dogs. The school forbids us from handling people who are not officially registered for the class, or members of the Cabrillo Astronomy Club (who will be along for your astro viewing pleasure), for insurance reasons as well as

cost. That means that those staying at our campground will need to register for the class.

* Car Pooling: It's a bit of a drive and carpooling will help save trees and keep you from getting lonely too! We'll organize carpools at the Wednesday pre-trip meeting.

The Graze of SAO 99020: What to Expect

   We'll set up about 3 or 4 "graze stations", spaced a few hundred yards apart. Each station will have a telescope, a designated observer, one or more assistants, a battery operated tape recorder, and a radio. The observer watches the star and each time it blinks out he/she shouts "D!", and when it reappears he shouts "R!", as absolutely instantaneously as possible. Meanwhile, his voice is being recorded on a tape recorder along with either time signals from WWV, or a suitable AM radio station to be decided on Sunday. It is by carefully listening to this tape that the times of the events will be deduced. The whole graze will last only about 3-4 minutes. The area of the moon being 'grazed' is never sunlit when seen

in silhouette from earth, so it'll be valuable new topographic data that we acquire.

* This trip requires car-camping. So, be prepared to bring or share....

-- sleeping bag, pillow

-- tent, rainfly

-- camp food (keep it in the car unless you're eating it!)

-- cooking gear

-- warm clothes (it's still winter, remember and it'll get cold  

   at night)

-- optional camera and tripod, would be fun

-- sunscreen, Ray-bans

-- binoculars would be nice

-- star chart if you have one

-- field notebook

-- daypack

-- lawn chair for relaxing/ listening to the lectures/tanning

*  The campsite is accessible by car so you do not need backpacks.

   We should plan to bring our own water. There will be rustic   

   restrooms, probably no showers. I'll root around for my old "sun

   shower" from the Hale-Bopp desert trip. 

* In addition, these items below are necessary for getting good  

  graze data:

-- tape recorder with FRESH batteries. This is necessary in order

   to make a careful voice record of the D's and R's so the times

   can be deduced.

-- audio tape for the tape recorder

-- If there aren't enough tape recorders/radios, bring along a stop

   watch if you have one

* Rain: The trip will go, rain or shine. If its raining (God forbid!) bring rain gear.


     We'll have our group meals on Friday evening and Saturday evening. Let's plan on starting meal prep at 5:30pm. We'll gather around the fire ring, slice tomatoes, etc.etc. and have a feast! At dark, we'll uncap the Cabrillo telescopes to view planets, double stars, galaxies, star clusters, nebulae, etc. For eager-beavers, there will be an opportunity to take some night photos (not through the telescopes, unfortunately) afterwards.  Rick will discuss various topics while you observe them in the telescopes. Saturday and Sunday during the day you'll be free to have fun. There's hiking, river swimming, mtn biking (bring yur own) Saturday after dinner, we'll have a 'round the campfire lecture on cosmology, galaxies, and the origin of the universe, then go to the telescopes for more viewing. We'll pack the graze telescopes before going to bed. Plan to head the sack early since the big event is at 2:54 am in the morning and we'll have to get set up. Remember that the moon waits for no one, so sleepy heads will be simply be left behind!

* Your grade will be based on attendence at all sessions, demonstrated curiosity, and especially on a take-home, open book final exam. Blowing your graze or asteroid occultation observations will NOT hurt your grade (assuming you don't sleep through it, that is!). You can take it credit/no credit too; just tell me.

   There will be more handouts and details on where we will be staying, etc. at the Wednesday in-class session. Please note that the Wednesday on-campus session is required attendence! I'm looking forward to a fun weekend with all of you!

Rick Nolthenius - instructor

Office 706a


rinolthe at