Home Regional Events Google Maps Multimedia & Archive SF Asteroid Occultations SF Lunar Occultations Asteroid Events Global TNO Predictions N America Pathmaps Honorable Mention Misc SF Grazes

All times UT unless otherwise noted

                BREIT IDEAS Observatory

April 5th, 2007

BREIT IDEAS "Saturn" Video chosen for inclusion on the NEW JPL "What's Up" feature



As posted on SkyTonight.com - Occultations on 02/07/07

The Best Asteroid Occultation in Decades:

A First Report

February 6, 2007
by David Dunham

This map shows the shadow path across the United States from the occultation of the star 32 Lyncis by the asteroid (372) Palma. The predicted path's limits are in blue, the actual ph appears in gray.
David Dunham

On the morning January 26th, at least 20 observers spread from Virginia to northern California timed the occultation of the star 32 Lyncis by the asteroid (372) Palma — in spite of the track shifting nearly half a path-width south of what was predicted. Although it was the coldest night of the season in many areas, it was clear over most of path and only a few observers were clouded out.

The observations can be fit to an ellipse with dimensions 207 kilometers by 184 kilometers (129 by 114 miles) to an accuracy of +/-2 km. The actual path was a little narrower than the predicted path. You can see the observations projected in the plane of the sky and the fitted ellipse here. In that figure, prepared by Brad Timerson and me, some departures from an elliptical shape are evident, such as a mountain at the north end of the asteroid that is left of center. The dashed line "21" is the last predicted central line of the occultation. The overall coverage of the predicted path was excellent.

This 1.5MB MPEG file shows the occultation of the star 32 Lyncis by the asteroid (372) Palma as seen by Derek Breit in Anderson, California. Breit created the film from about 300 frames. At his location the star blinked out of view for 5.2 seconds.
Derek Breit

The largest expedition was organized from the San Francisco Bay area by Derek Breit. Those observers were joined by Richard Nugent from Houston, Texas, and Mike Hoskinson from Edmonton, Alberta. They gathered at a motel in the small town of Anderson in the northern Sacramento Valley several hours before the occultation and decided how best to deploy their five stations near exits from Interstate 5. Good video recordings of the occultation were obtained at each station. In a similar effort, Paul Maley flew to Salt Lake City, where he met local observers who set up three stations near Ogden, Utah. Unfortunately, Maley braved temperatures of 13°F but saw no occultation. Still his observation was valuable, being the closest observer to the northern limit to have no event. His results constrained the shape of the asteroid.

Although about half of the mobile stations were too far north to see the occultation, the negative results did show that no satellites of Palma larger than about 4 km could have been on the northern side of the asteroid.

Maps showing the last predicted and actual paths of the occultation, and more details about the observations, are at http://iota.jhuapl.edu/mp372.htm.




As posted on www.universetoday.com on 10/28/05

 Amateur Observers Are Seeing Double


Summary - (Oct 28, 2005) As Derek Breit headed for Fremont, California on April 15 to observe a lunar grazing event, little did he know that he was about to make a discovery that would change the way we look at standard stars. As he set up his 12" Meade SCT and prepared to record the event with a low lux videocamera, it seemed like a fairly routine observation. Until he reviewed his tapes. As frame by frame moved by, he noticed something a little unusual about upsilon Geminorum - a standard star against which others are measured, especially in the infrared. In 55 frames of his video footage, he apparently captured what may be the very first look at a 11th magnitude companion on a slightly variable star not known to be a double.

Full Story -

Image credit: Derek Breit.

Findings of this nature are one of the many reasons why International Occultation Timing Association (IOTA) members pursue their craft. One of the notable and historic discoveries on a standard star by occultation means happened in 1819 when Antares' companion star was observed. However, the name of the astronomy game is confirmation - and also filming and timing the northern limit event at differing locations were Walt Morgan and Ed Morana.

Contacting IOTA's Dr. David Dunham, Breit forwarded his findings, contacted team members and started seeking an answer for two unusual seconds of video. According to Dunham's response, "Almost 2 seconds with a distance of much more than a km; it's unlikely that the Moon would be that smooth, it would have to be within about 5m or less for the brightness to remain faint and constant at that level so long. Especially since this apparently occurred at nearly every event, a faint, close companion, only 0.01" to 0.02" north of the primary, seems likely."

And Morgan clarifies, "The disappearances and reappearances by upsilon Geminorum as it passed lunar peaks were usually slow transitions, that is, the star appeared to fade (or brighten) over a matter of several video frames. That was not considered unusual because of the fairly large angular diameter of the star. However, in some instances the magnitude 4.1 star did not seem to completely disappear on Breit's record: a very faint point of light remained visible right at the lunar limb."

But confirmation of such importance to the scientific community doesn't stop there. Breit's findings went out to all IOTA observers and the critical timing information provided them with the clues they needed. Also recording the event was Dr. Richard Nolthenius, whose answer was, "Derek's right! I've just reduced my upsilon Gem graze video recording from last Friday. I used a PC164c on an 8" f/10 operating at f/6.3, recorded on my Canon ZR45mc. And the conclusion is.... Derek's camcorder is not going crazy! I fully confirm his observations and conclusions - this star is a very close double star."

As they continue to work through the geometry and astrometric angles, Dr. Nolthenius offers the following information from his own recordings: "The second and 3rd D's look especially like there is an 11th magnitude companion, and the final D most dramatic of all, with the initial fade happening in just 3 frames, followed by a definite but very faint 11th magnitude star left over for fully 1 second before finally disappearing."

Although it might seem that in a sky filled with innumerable double stars that a revelation of this type would be of little significance, IOTA member - Dr. Michael Richmond - knew better: "I did a little searching to see if there was any other indication that upsilon Geminorum might be double. The Hipparcos observations indicate that it is slightly variable, with an amplitude of about 0.08 mag, but there is no indication of a period. The Astrophysics Data Service has a number of references which mention upsilon Geminorum. This star has been chosen to be a calibrator for optical interferometers; that is, people have decided that it's a good star to use as a reference when doing high angular resolution measurements. There are two recent papers which list measurements of its angular size: Borde et al. (A&A 393, 183, 2002), which finds an angular diameter of 5.00 +/- 0.051 mas, and Richichi and Percheron (A&A 386, 492, 2002), which lists angular diameter of 5.23 +/- 0.31 mas. Given the Hipparcos parallax of 13.57 mas, this means that the star's diameter is roughly 0.37 AU. The main star has spectral type listed as late K or early M giant, with V-band mag 4.08 and K-band mag 0.24. If this is a double star, with a companion of roughly mag 11, then it would be important to let other astronomers know: it would no longer be a really good calibration star."

But, Dr. Richmond did not let his findings rest there and he continued to look for more precise information. Says Richmond, "I found that both of the catalogue entries were NOT based on direct measurements of angular size; instead, they were simply estimates, based on the observed brightness and the shape of the spectrum. In other words, they were basically fits to a blackbody with a given temperature. I was surprised to find such indirect evidence appearing in catalogues of angular size, for use as a calibrator for interferometers."

Recognizing the importance of such a finding as opposed to known data definitely changes the way we perceive information. Astronomy is a continually upgrading science as Dr. Nolthenius notes: "For some 9th magnitude star, finding yet another double is one thing, but for such a bright star, being a standard for certain measurements should be checked, as you did. The star is apparently in that fall-through-the-cracks area of parameter space: a wide enough double to not make for noticeable periodicity in the radial velocity on a time scale of a few years - the period is likely in the 100+ year range, (although this is something I will calculate later) and yet impossibly difficult as a visual binary without using interferometry or lunar occultations."

Of course, there is far more to this picture than just the discovery of undisclosed double star. By recording, timing, and observing both grazing and occultation events, IOTA is able to help determine proper movement, orbit and lunar limb features as well. As Dr. Nolthenius explains, "The absolute UT's of the events will help in assessing the slope of the moon at the event points. However, the most convincing case for duplicity will be identifying significant periods of time of constant brightness at the very faint levels." The diffraction of large stars aids astronomers in making more accurate calculations, "Perhaps there is a secondary that is of order 1 radius or less above the surface of upsilon Geminorum." hypothesizes Nolthenius, "If such extended periods of very faint levels might be consistent with limb darkening which is very extended. As a K giant, I would not expect the limb darkening to be so extreme - normally limb darkening is more extreme the cooler the star, and late K is not all that cool."

More confirmation was needed and the findings were sent to Dr. Mitsuru Soma of the National Astronomical Observatory of Japan. Says Soma, "From the comparison of your faint flash mentioned above and the short duration (0.7s) from R to D of the primary of Walter Morgan the companion's separation from the primary is estimated to be about 0.04 arcsec, and this is consistent with the duration of your gradual R's at 4:39:07 and at 4:40:21 (UT). The spectral type of ups Gem is K5III which is the same as Aldebaran according to the Hipparcos catalogue, so I assume that the actual radius of ups Gem is almost the same as Aldebaran. The angular radius of Aldebaran was estimated to be about 0.010 arcsec from lunar occultations."

But confirmation means being very sure that there is no chance of this being a diffraction effect. As Dr. Soma explains, "The distance to ups Gem is 3.6 times the distance to Aldebaran (ups Gem's parallax is 0.014 arcsec and Aldebaran's parallax is 0.050 arcsec) so the angular radius of ups Gem should be about 0.003 arcsec, which is small so that I think the error arisen from the assumption that the star is a point source is almost negligible when we estimate the diffraction effects. Referring to this fact I think 0.04 arcsec I mentioned above is too large to be attributed to the diffraction effects."

Confirmation continues on a deeper level when Dr. Michael Richmond plots the photometry of all three tapes of the Upsilon Geminorum event: "The thing I find very interesting and encouraging is that I see an asymmetry in these light curves." says Richmond, "If this is true, then I think we can make a good case that there may be a faint companion to the primary star. The companion must be "ahead" of the primary, so that the moving limb of the moon first blocks (or reveals) the companion, before it blocks (or reveals) the primary."

Dr. Mitusuru Soma also continued with his analysis and presented the papers at the Journees 2005 meeting in Warsaw on 2005 September 19-21. Based on available information says, "My conclusion about the position of the secondary of upsilon Geminorum relative to the primary is 0".04 +/- 0".01 in separation and 70deg +/- 20deg in PA." Although these findings are preliminary, Soma will continue to review the data and clarify the results of all accumulative information.

Seeing double? The answer is quite probable. In the mean time IOTA members will continue to review of the data and further research the duplicity of upsilon Geminorum. There's a whole big wide sky out there, and each time an observation of this type is made it adds more to our understanding. While speckle interferometry is cutting edge of double star detection - the occultation method can reveal far more. Contributions from dedicated members are what makes the International Occultation and Timing Association play an important role in today's astronomy.

Says Breit, "It was a pretty darn good feeling when Dr Nolthenius wrote "Derek's RIGHT!" When four PhD's say I have found something special doing a hobby I taught myself from the age of six, that's pretty good. Something to tell the grandkids... But my real thought was that I finally have a great video to show others and hopefully get them interested in observing these very dynamic and temporal events!" So what are the chances of IOTA members Derek Breit, Walt Morgan, Ed Morana and Michael Richmond making a contribution to the scientific community?

I'd say double.

Written by Tammy Plotner.



As Appeared in the July 2005 Occultation Newsletter

“Incredibly Lucky”

The Surprise Graze of ZC 2131

By Derek C Breit

BREIT IDEAS Observatory

  It started out as any other day of videotaping total lunar occultations.  On Sunday July 25th 2004 local time, I was setup to videotape some events. These would turn out to be the 6th – 9th events recorded to video with my new Watec 802h videocamera.

  I was quite enthralled with the occultation game to begin with and this new camera was like the holy grail to me. I had immediately imaged the nucleus of the Andromeda Galaxy, the Orion Nebula, and other similar objects. There was no beating this camera!

  This was a Sunday, my usual off day, so I was going to observe whatever was around, regardless of how spectacular or not the predicted events were going to be. So I generated predictions with WinOCCULT. There were quite a few, but these are the ones I successfully observed on video with WWV time signals.

 04 07 26  3 58  8 d X 38668 F8 10.4   61+ 103  -7 31 200  53N  69  52  54

04 07 26  4 27 59 d  158899 G8  8.4   61+ 103 -12 29 207  53N  69  47  54

04 07 26  5 33 47 d    2131 F5  7.7   62+ 104     21 222   6S 190 156 175

04 07 26  5 37 37 d X 38718 F8 10.2   62+ 104     21 223  41S 155 121 141

  Being July in California, the weather was quite comfortable. This caused my wife to come see what I was doing at a very convenient time. The moment was fast approaching for the total occultation of ZC 2131 at a cusp angle of 6 degrees south. I was very new to occultations, but I learned quickly about the ruggedness of the terrain near the South Pole of the Moon.

  “Honey, if we are really lucky, this star (on the TV Monitor) will blink off and on behind a mountain”, I said, employing one of my favorite traits – WISHFUL THINKING. Seconds later, the star disappeared at 05h 33m 19.5s UT. “Come on back! Come on back!” I kept repeating. Julie and I were amazed when it did just that at 05h 33m 34.4s with a gradual reappearance. At 05h 33m 46.0s, it disappeared for good. I plotted the grazeline and learned I was 121 km North of the Southern Limit. An event like this would have to be, by its nature, pretty rare.

 How rare? Just how lucky was I? Let’s see if we can find out!


DR Mitsuru Soma wrote on August 1st 2004 –

Derek's deepest point was -26.301" from the mean lunar limb at

05:42:17.860 UTC… As may be seen from my reduction shown below, Derek's multiple events are due to a very steep profile of the Moon.


   WA   Height   WH   Diff   l     b      Star    Phen

    o     "      "     "     o     o

174.55 +1.782 +1.50 +0.28 -5.88 +2.06  ZC  2131   DD

174.92 +0.278 +0.06 +0.22 -5.88 +2.06  ZC  2131   RD

175.21 -0.866 -0.83 -0.03 -5.88 +2.06  ZC  2131   DD

WA: Watts angle

Height: Observed height from mean lunar limb

WH: Height in Watts' charts

Diff: Height - WH

l,b: Libration of the Moon



 So, that is all fantastic, but was does it take to see a representation of the profile that gives some context to how incredibly lucky I was to observe this event? I tried a standard graze prediction from OCCULT. No matter what I did, I could not generate a profile for this event at a Watts Angle of 174.92, the middle event mentioned by DR Soma above. After some extended conversations with the Author of WinOCCULT, I can now demonstrate how to display any profile.

  First, let’s return to my results. I record all my observations in the Report Observations module. At the time, this was the 38th, 39th, and 40th event of my occultation career. The prior events were all Total Occultations. There are 43 observations in this file. Here are the ones that pertain to this graze.

 38200407260533195  R   2131           1VSRS3 01 1   22221  6                 AAA

    WWV Good on 5mc

39200407260533344  R   2131           2VSRS3 01 1   22221  6                 AAA

    WWV Good on 5mc- Gradual R

40200407260533460  R   2131           1VSRS3 01 1   22221  6                 AAA

    WWV Good on 5mc

  If you use OCCULT to record your observations, the above will be familiar to you. If you are new to OCCULT, when you enter your observations, you will end up with something similar. This is a very useful file!

  If you “open the Reductions module, select the 'Reduce Lunar Occultations' option, and reduce the observations in this file. In doing this, select 'Normal', and 'apply corrections'. You will now have displayed a short text list of the reduced observations. On that form, under 'with displayed observations' select 'Plot against profile - Graze observations only'.

  The results look like this for this surprise graze.


 Then you select the menu option 'Profile information...   Display P,D profile from Historical grazes' and you get the following, which I have highlighted to point to the three events shown above.


  This puts an excellent context to the events I saw. This is a very useful feature and one I will use frequently, but possibly in a manner not thought of by others.

I will use this feature not only to visualize what I have seen, but to VISUALIZE WHAT I MAY SEE!

  I will generate a set of total predictions. I will take any predicted event and note the predicted time and create a temporary observation file that contains 3 events. First event will be 15s before predicted, second will be the predicted time, and the third will be 15s after predicted. Using the instructions and examples above, I will learn what features may effect the observation and I will have a graphic representation of the direction of the Moon’s motion at the time of the event. Who knows? Maybe using this great feature of OCCULT, I maybe able to become even more INCREDIBLY LUCKY!

 Derek C Breit



As appeared in the “Occultation Newsletter” in January 2005

The SF Bay Area “In The Path”

On the Cover:
Steve Preston posted a prediction for the occultation of a 10.8-magnitude star in Orion, about 3° from Betelgeuse, by the asteroid (238) Hypatia, which had an expected diameter of 148 km. The predicted path passed over the San Francisco Bay area, and that turned out to be quite accurate, with only a small shift towards the north, enough to leave Richard Nolthenius, observing visually from the coast northwest of Santa Cruz, to have a miss. But farther north, three other observers video recorded the occultation from their homes, and they were fortuitously located to define three well-spaced chords across the asteroid to accurately measure its shape and location relative to the star, as shown in the figure.  The dashed lines show the axes of the fitted ellipse, produced by Dave Herald's WinOccult program. This demonstrates the good results that can be obtained by a few dedicated observers with a relatively faint star; a bright star and/or many observers are not always necessary to obtain solid useful observations. – David Dunham

 The Occultation Newsletter is a publication of IOTA


 10,000th VISITOR

Kiwi Geoff, Tom Webber, and David Breadsell were the 10,000th visitors to my website.

The prize each of you will receive is a set of twenty 8 ½” x 11” Lithographs from JPL titled “Our Solar System”.They are quite nice with spectacular images on one side, and textual data on the other. I have a set on my wall behind me. I hope you three enjoy them as much as I do.

 I created this website about 13 months ago to keep myself informed of Occultations in my area and now it has passed 10,000 visitors in just over a year. Many thanks to the website owner, without whom this webpage would not be possible, ”Wifey” who allows me to be me, and to everyone who finds this website useful.

 See you at 20,000 when I have a better hit counter!

 Derek Breit – BREIT IDEAS Observatory


If you live in the SF Bay Area (or anywhere else, for that matter) and wish to know how you can become involved, click the above link or use the “Contact” link below to email me directly. – Derek Breit



SF Lunar
Derek's Graze Archive
Derek's Grazes
Morgan Hill Grazes
Google Maps
Diary of Astronomical Events
Previous Global Asteroid Events
Global Asteroid Events
Future Asteroid Events
Global TNO Events
SF Bay Area Extra Events Detailed Info
SF Bay Area Mutual Events
Watec 802h Switch Settings
M67 Photometry
Dr. Dunham Messages
12v - 18v Converter
Setup Images
Animated Gif Images
Lunar Occultations - Reporting Timings
Balancing a Piggybacked ST80
Dual Video with GPS Timestamps
Driftscan Timing with a Mintron Camera
RASC Handbook Events
Cool Vest
WWVB Video Clock
Building an Observatory
Special Asteroid Events
Sharks Hockey
Global TNO Events
Sandy Bumgarner

Site Meter


This site was last updated 08/10/16

© Copyright, Derek C Breit. All rights reserved.