Stars Over Yosemite


Yosemite National park — August 12 – 13, 2016

Park visitors:

This star party is not the “Glacier Point Stargazing Tour” (a bus tour) conducted by the Delaware North Company for $41.

This page describes one of a series of free star parties that are conducted by amateur astronomy clubs, this one by the San Jose Astronomical Association. There are several more clubs that come up on other weekends from late June through the first weekend of September (Labor Day). These club-run star parties are open to all park visitors.

Astronomers and Park visitors:

The annual SJAA Yosemite star party is held at Glacier Point. Any park visitor is welcome; there is no fee. Children from about age 7 years and up are welcome; younger ones may have trouble getting up the ladder to the telescopes’ eyepiece.

The astronomer’s camping space is at the Bridalveil Creek campground, about 9 miles from The Point. There is room for several tents. The camping is rough by modern standards: no dining room, no showers, no hot water. The camper limit is 30 feet, but that’s really too big for the sites that we use; a van camper is much preferred.

We are given free admission and camping space. In exchange, we are expected to set up our telescopes for both public star parties at Glacier Point, on Friday and Saturday night. If you have never set up for the public, this is definitely not the place to try it for the first time!

We have the public (about 200 – 300 people) arriving about sunset or somewhat later. By about 11 to 11:30, most of them will have left, and we will have the rest of the night to ourselves.

For all these reasons, this is not suitable for a family camping trip.

We may take a maximum of 30 people, with priority given to SJAA members. We are expected to have at least one public telescope for every two people. If you can tolerate the conditions outlined, write to Jim Van Nuland with the number of people and telescopes. If you would rather arrange your own housing, let Jim know that too, and how many telescopes you’ll set up for the star party.

Jim will mail the gate passes a few weeks before our weekend.


The luck of the date raffle gave us a moony weekend this year. The moon will be approaching full, so we’ll have to concentrate on bright objects to show the park visitors.

For those past the 30-person camping limit, or who will make their own arrangements at a motel:

Yosemite is your park, and you are welcome come if you arrange your own accommodations. You would be welcome to join us at Glacier Point for the public star party and the general observing afterward.

There are several motels in the community of Yosemite West, which is much nearer than the inns on the valley floor. Try googling on “Yosemite West”.

If you will set up a telescope, let Jim know that you are coming. Please send a mailing address.

If you have not been to a Glacier Point star party before:

Download Gary’s detailed directions, which include:

  • Directions via Hwy. 120 to Yosemite’s Big Oak Flat (north) entrance, with maps and notes;
  • Details on the Bridalveil campground, with maps and photos;
  • Directions and information on the star party at Glacier Point;
  • Abbreviated version of the directions (easier to use while driving);
  • Notes on the trip back home.

In addition, peruse the FAQ page for various tips.

When you arrive at Yosemite, make your way up to the Bridalveil Creek campground. Do not confuse it with the walk-in viewing area at Bridalveil Fall. From that area, the driving distance is 18 miles, uphill and twisty. Allow about an hour from the Fall parking lot, but make a stop at the Wawona Tunnel overlook, which is the classic view of Yosemite Valley. Try to reach the camp by 4 pm at the latest.

At the campground, go to loop C, and find sites 81, 83, 85, 94, and 95, with “Reserved for Park Volunteers” on them. All are on the left side the road, along a long curve. The curve and sites enclose a large common area “behind” the sites, where tents can be set up.

Note that sites 89 and 93 are not volunteer sites, even though they fall between the volunteer sites. We will try to buy them, but if they do not have “SJAA” or “JVN” on the number post, they are not ours.

From the camp, Glacier Point is another 9 miles up the road. Allow time to find your way and set up; the summer sunset is late, so there’s adequate time. We usually are setting up by 6:30, as we can bring in only a few vehicles at a time to unload, and they must quickly be returned to the parking lot, even before you set up.

The observing area is partly open, with good views from about NNW to the east, around to due south. From south around past west is partly to mostly blocked by tall trees. Still, there’s a lot of open sky, and typically, the seeing and transparency are excellent. It is typically warm (80 to 90) during the day, and cool to chilly (40) at night, due to the elevation, 7200 feet.

On each evening, we may take a group picture about 10 minutes before sunset. Picture time will be 7:40 pm in 2016.

One of the rangers does a sunset talk, and then delivers the crowd to us. Some will have flashlights, and we need to be tolerant of that. Pick out a show object that you are familiar with, tell about it, etc., just as we do at Houge Park and schools. Hopefully we’ll be on different objects. Expect lots of questions. By 11 or so, most of the public will have left. We’ll have the place mostly to ourselves, and can stay until dawn.

Scopes must be removed when we quit, then set up again on Saturday. We have two “leaving windows” (midnight and 3 am) to manage the lights associated with packing up. Please be considerate.

Miscellaneous questions and answers are tossed onto the Yosemite FAQ page.

Sun and Moon data

The Moon will be moving toward full, so we’ll need to find bright objects for the park visitors. Adding insult to injury, it will soon move behind the trees, so we can’t show it.

The following times do not allow for the elevation or local horizon, so rise times will be late by about 30 minutes near east, and by about 45 minutes when the object is northeast or southeast. The error will be even larger when the object is behind a mountain peak.

Times are Pacific summer time (UTC-7 hours)

            August 12     August 13  2016
             Friday       Saturday

Sunset:       7:54 pm       7:53
 azimuth:      289 deg.      289 deg.  behind the trees
C-twilight:   8:22          8:21       Sun  6 degrees down
N-twilight:   8:56          8:54           12  "
A-twilight:   9:32          9:30           18  "

 ------- next ------- day -------

Moonset:      1:49 am       2:35 am
 azimuth:      247 deg.      246
 illumination   74%           83%

A-twilight:   4:35 am       4:36 am  Sun 18 degrees down
N-twilight:   5:20          5:20         12  "
C-twilight:   5:45          5:46          6  "

Sunrise:      6:13 am       6:14 am
 azimuth:       71 deg        71 deg

Moonrise:     4:16 pm       5:08 pm
 azimuth:      114 deg       114 deg
 illumination: ~79%          ~87%

Longitude:   119 deg   34.6 min
Latitude:     37 deg   43.5 min
Elevation:  7200 feet  WGS84

Pictures and links  Click pictures for bigger versions

[Image: Team 2015 at Yosemite N.P.]

SJAA Team 2015 at Glacier Point, Yosemite National Park
Photo: Michael Packer’s camera

[Image: Bear in Glacier Point parking lot]

An unwelcome guest: bear in Glacier Point parking lot.
Photo: Hsin I Huang

[Image: Bear entering lower observing area]

Bear entering near fire ring. Do not bring any food into the observing area, not even sodas!
Photo: Craig Wandke

For 2014 pictures, go to Morris’ Yosemite 2014 page.

For extensive 2006 pictures, go to Morris’ Yosemite 2006 page.

Last updated: 2016 Mar.15, 22:01