2011, July 28 - The story on the discovery of the February eta Draconids broke today after a report in Space.com and an article in the San Francisco Chronicle with a front-cover lead.
2011, July 25 - Today, we surpassed the number of 7,000 meteoroid orbits reduced. You can keep track of the score here. Data reduction is gradually catching up, thanks to efforts by Meridel Phillips, Bob Haberman, and Peter Jenniskens. Data up to mid May have now been analysed, with one week in January and much of April still to do. Recent weather has been generally good. A power outage at Fremont Peak caused three lost days July 21-23, which hopefully are covered by Lick and Lodi.
2011, July 18 - SETI REU students observed the occultation of double asteroid
90 Antiope from locations in the Central Valley of California in
the night of July 18 . Here, Meridel Philips and Shannon Hicks
test out the instruments at the CAMS Allsky Meteor Surveillance
station at Lodi, where the occultation lasted about 19 seconds.
A second picture shows Meridel watching while Antiope moves
in front of 6.7 magntidue star HIP 112420 from a second location
near Wallace, California, where the occultation lasted about 16
seconds. Photos by Peter Jenniskens. Three other teams observed from sites near Rocklin and Tracy.
The effort was led by Franck Marchis of the SETI Institute, with assistance
from Emilio Enriquez of the SETI Institute and
Keaton Burns of U.C. Berkeley. The SETI Institute hosted researchers
from the Observatory of Paris in France, Francois Colas, Jerome
Berthier, and Frederic Vachier, who had specially come out to the
San Francisco Bay Area to view the occultation [[Preliminary Results]].
2011, July11 - Pioneer asteroid hunter (Palomar-Leiden asteroid survey) and founder of SpaceWatch, astronomer Tom Gehrels passed away today. Read about his remarkable life here.
This +2 magnitude February eta Draconid was filmed by
Peter Jenniskens with one of the low-light-level video
cameras of the Cameras for Allsky Meteor Surveillance (CAMS)
station in Mountain View, California, at 07:59:24 UT on February 4, 2011.
2011, July 10 - New shower discovered! The Central Bureau for Astronomical Telegrams of the International Astronomical Union issued today this TELEGRAM announcing the discovery of the February Eta Draconids.
Although CAMS was designed to confirm previously discovered showers, a meteor outburst was detected in CAMS February 4 data obtained at the Fremont Peak (Rick Morales, Loren Dynneson, et al.) and Mountain View (Peter Jenniskens) stations. This is the first new shower discovered by CAMS. It is also a very unusual shower, of a type that only occurs once or twice every sixty years and is caused by the dust trail of a (still to be discovered) potentially hazardous long-period comet. The new shower was named the February eta Draconids and is now listed as shower 427 in the IAU Working List of Meteor Showers. A paper on this discovery was submitted to the Journal of the International Meteor Organization [[read paper pre-print]].
2011, June 25 - Pete Gural visited the Bay Area on June 25 and presented a talk at the Fremont Peak Observatory StarBeQue. Some hundred people were in attendance. A cake was shared with the audience by Peter Jenniskens, Mike Koop, Pete Gural, Rick Morales, Chris Angelos, and David Sammuels to celebrate the discovery of the February eta Draconids. In other news: SETI Institute REU students covered the windows of Fremont Peak Observatory with heat-reflective foil.
2011, June 21 - Temperatures in the central valley rose to 103F today. Peter Jenniskens and Meridel Phillips visited the CAMS setup at Lodi to check the performance of the computers in this heat. The "chicken coop" built by David Holman functioned extremely well. The temperature inside the coop was much the same as outside in the shade. Three of the five units had run uninterrupted from June 8 to 21. The other two units had stalled during data collection at night (Unit 1 on June 10, Unit 4 on June 20), possibly due to low voltage.
2011, June 20 - Peter Jenniskens and Meridel Phillips met with College of San Mateo Observatory staff Dean Drumheller (pictured) and Daryl Stanford, and one of their students, to test the first CAMS@San Mateo camera, the prototype for a single-camera CAMS system that can be copied by participating amateur astronomers and educational institutes. The camera saw first light, but we were baffled by why EasyCap couldn't read the settings file. This issue is being worked.
2011, June 15 - Peter Jenniskens, Meridel Phillips and Jon Reijneveld visited Lick Observatory and serviced CAMS. Meridel installed a poster at the trailer that explains the project to visitors. Briant Grigsby gave a tour of the 3-m telescope. A new protocol was installed that shuts down the computer at 1 pm and starts up at 7 pm. At twilight, an incredible sun pillar was observed, which lasted until long after sunset (picture below by Peter Jenniskens).
2011, June 17 - Jim Albers calculated this coverage map of the current layout of the CAMS stations.
2011, June 12 - Kevin Newman has returned to the Ames Exploration Academy, now as a leader. Student Jon Reijneveld will assist Peter Jenniskens this year with CAMS and other meteor shower observations.
2011, June 12 - Rochester University graduate student Meredith Phillips has arrived at the SETI Institute to participate in the SETI Institute Research Experience for Undergraduates program. She will assist in the CAMS data reduction.
2011, June 11 - CAMS is 17% better than thought before. By using a smaller limiting convergence angle (Q > 10 degree, instead of Q > 20 degree), 17 percent more orbits were obtained at good precision. Reason that the lower convergence angles work also, is because of the method of trajectory reconstruction that is applied. November 2010 data now amount to 2286 orbits. In the new data reduction, we also saved the lightcurve and positions plots as jpg files.
2011, June 8 - Pete Gural has build a one-camera version of CAMS which can be used to add cameras to the CAMS project, or setup a separate CAMS network. He has put all software elements in place for a single user to be able to calibrate and operate the camera and view the results. The system will now be tested by the San Mateo Astronomical Society (Marion Weiler) at the San Mateo College observatory.
2011, June 7 - Dave Holman and Peter J visited the Lodi station and confirmed that the setup was able to handle the recent bad weather well. The computers were dutifully collecting data on clouds. Minor improvements were made and the focus of the cameras was checked against a clear sky. A period of good weather is ahead.
2011, May 31 - The Mountain View station of CAMS was moved to Lodi, at the invitation of Tom Hoffman and his wife Carmela (inset), who own a winery in the area. Mountain View is prone to fog in the summer. Dave Holman built a custom-made "chicken coop" to house the computers. The coop has vents front, back, bottom and top, and is designed to reflect sunlight to keep the computers at a suitable operating temperature. As of 8:15 pm, May 30, the Lodi station was in operation, with all cameras operational later that evening. The weather is cloudy for now.
2011, May 25 - An overview paper "CAMS: A video Camera based Allsky Meteor Surveillance for shower verification", by P. Jenniskens, P. S. Gural, B. Grigsby, L. Dynneson, M. Koop, and D. Holman, was submitted for publication in Icarus. It contains the analysis of the first batch of CAMS data.
2011, April 23 - The Lick Observatory station is in operation! The camera trailer was hauled up to Lick Observatory this afternoon by staff astronomer Bryant Grigsby (photo) and family. The computers and camera box were transported inside the car. After refreshments at the Grigsby residence, we positioned the trailer at the allocated observing site and repositioned the camera box and computers. As of 7 pm that evening, CAMS@Lick was operating. After dinner, we verified that all 20 cameras were operating nominally and were free of obstruction. They were, and only one connector needed slight adjustment.
2011, April 22 - The agreement to facilitate the deployment of CAMS at Lick Observatory was finalized today. We received permission to move the CAMS trailer up to Lick Observatory.
2011, April 12 - Pete Gural has now also completed the recalibration tool to enable a nightly calibration of the data. This completes the basic software toolset needed for CAMS. We are now recalibrating the data from the first day of observation.
2011, April 9 - Preparations for deployment of CAMS at Lick Observatory are moving forward. Following a meeting with UCSC/Lick Observatory staff last Thursday, David Holman and Peter Jenniskens mounted the camera box for the Lick Observatory station on top of the trailer, thus making it a fully mobile and self-contained unit. The setup is currently being tested in the SETI Institute parking lot. Ventilation is sufficient and the computers inside appear to run well.
2011, March 18 - Pete Gural has finished the orbital element part of the reduction pipeline.
We now have a first version of geocentric and heliocentric radiant and speed as well as orbital elements. Results were tested against the published Neuschwanstein data, one of the more precise orbits in the literature. The Neuschwanstein results were reproduced within the reported error bars. Smaller differences continue to exist and we are checking the more subtle aspects of the calculations.
2011, March 17 - Mike Koop installed a power monitor at Fremont Peak to help isolate a persistent problem of some units, after working well for several days, continueing to hang up during processing and when atempting to write the very first file of the night. No such problems exist for the Mountain View station. Weather has been cloudy since mid February.
2011, February 9 - Mike Koop and Peter Jenniskens picked up the five servers for the third station from Lorena Perez at BCSI on Friday and set up the new equipment in the trailer. Mike also finished the power supply filter for this station. Peter hooked up the power connectors and the camera box for the third station is now assembled. He finished crimping the 20 bnc cables to go from box to servers. On Tuesday evening, Bob Haberman and Peter tested the equipment at the SETI Institute, adjusted the computer settings, and focussed the cameras on the stars. Bryant Grigsby and Peter subsequently cleaned the glue from the plastic film covering off the optical glass window. This station, intended for Lick Observatory, can now be put into operation.
2011, February 2 - After a few day of clouds, the weather has returned to a clear spell. Peter Jenniskens and Bob Haberman have added one extra UPS unit to the setup at Fremont Peak. We hope that this solves a persistent issue of some units freezing up periodically.
2011, January 29 - Peter Jenniskens has replaced the lid and motor cover at Fremont Peak, which needed repairs after the bad December weather.
2011, January 18 - Pete Gural has completed software that steps through the collected data and verifies the coincidences. The effort is interactively, asking the observer to verify each coincidence by means of the graphs above. This makes it now possible to tally the number of detected meteors in each night. We are now processing the data in hand so far and the meteor tally already has gone over 1,000 orbits. In the current configuration, we are detecting about 130 meteors in every clear night.
2011, January 12 - Early this morning, Fremont Peak was shaken by a 4.5 magnitude earthquake just 5.5 miles SSE of San Juan Bautista. This puts the quake right under the home of FPOA Treasurer and CAMS@FPO volunteer Mark Levine. "We got quite a wake-up call!" wrote Mark. "I'll go up this afternoon just before sunset and check things out." Upon return, Mark reported no damage.
2011, January 9 - David Holman visited the SETI Institute to modify a small trailer which will be used to house the CAMS camera servers at Lick Observatory. The trailer was equipped with air vents at the bottom and side, and with several input ports for power and video cables.
2011, January 8 - While servicing the Fremont Peak station, Peter Jenniskens gave an impromptu talk for a group of boy scouts and their parents.
2011, January 3 - The Quadrantid shower peaks tonight. Finally a break in the weather. This is already one of the wettest winters ever in our area, with many clouded nights in the month of December.
2010, December 9 - This shows the apparent radiant distribution of meteors filmed by CAMS in the night of November 1, 2010. The Taurid and Orionid showers are easily recognized. In addition, there is much other clumping that could identify minor showers. The sporadic background appears to be modest. Most meteors captured have absolute magnitudes in the range +3 to +1. The tally of good orbits for this night now stands at 153.
2010, December 4 - Pete Gural has adapted the mosaic tool to accept the new astrometric calibration. The figure shows the field of view from both stations. Notice how the actual fields are slightly curved in this gnomonic projection. Also apparent is how the temporary site in Mountain View, which is tilted south for better overlap with fremont peak, is partially obstructed by trees, permitting only 12 of 20 cameras to collect data.
2010, November 27 - We noticed that our initial lightcurves as seen from the two stations did not perfectly line up. They tended to be shifted by 1-3 frames. Pete Gural today improved the calibration of the plate constants and the camera orientation by now using 50 - 100 stars and fitting a cubic polynomical surface to the measured star positions. The result is very satisfying: the lightcurves line up perfectly now. Shown is a meteor from November 1 with an abrupt termination. Black points are the light curve as seen from Fremont Peak, blue points shows the one detected in Mountain View (where the meteor entered the camera field).
2010, November 17 - The Leonid shower peaks tonight.
2010, November 15 - Data for November 4 are being reduced, the tally of good orbits so far just over 50! A first look impression shows the distribution of the apparent radiant positions of these meteors. Results are compared to those obtained in the past by photographic techniques (IAU database). In the mean time, the reduction pipeline is being improved.
2010, November 14 - The photometric data look good too. Here is an example of lightcurves derived for some of the November 5 meteors. Two very different cases are shown. There are small shifts in the curves as a function of altitude (not shown), which need to be resolved.
2010, November 14 - Clouds are normally our worst enemy, but this afternoon they inspired appreciation. As in a sign of celebration, the sky over the new SETI Institute building at 189 Bernardo Avenue in Mountain View showed iridescent clouds. This picture was taken at 4:30 pm by Peter Jenniskens.
2010, November 11 - First light! Pete Gural has finished the movie generator, the post-processing and the coincidence software. Peter Jenniskens analyzed the data for November 5, 2010, which produced 15 trajectories from good observing geometry, more than doubling the 11 precisely reduced orbits known to date for solar longitude 222 degrees.
The astrometry is so accurate that the slower meteoroids can be seen slowing down while penetrating the atmosphere. The graph above plots the speed of two meteoroids as a function of altitude, each dot is the speed measured between two video frames. Fitting the expected behaviour of a non-ablating sphere provides the initial velocity at the top of the atmosphere to a precision of a few tenths km/s, thus providing an accurate orbit in space.
Performance of the system so far: Data for November 5, 2010, were chosen to be first analysed. The weather was partially cloudy. Fremont Peak detected 150 meteors (12.5 meteors/camera, with 12 cameras operational). Mountain View detected 84 meteors (8.4 meteors/camera, with 10 cameras operational), the lower number mainly because of clouds and obstruction by trees at this site. Fremont Peak had only 12 out of 20 cameras operational due to a software error that briefly disabled two of the units, and the temporary station at Mountain View only 10 out of 20 due to obstruction by trees. That left only about1/3 of the sky covered by both stations simultaneosly.
Our goal is to obtain at least 100 precise orbits per degree of solar longitude in three years of CAMS operation. It now looks that we can meet that goal for most nights (weather permitting), once the Lick Observatory site has been established.