*** ASTRONOMICAL EVENTS FOR HOUSTON, TEXAS ***
The main objectives in pursuing and observing asteroid occultations are:
- to develop information on the shape and size of minor planets
- to discover a possible hidden companion to the star being occulted
- to detect the existence of a natural satellite companion to the asteroid
- to verify the accuracy of the astrometric prediction
Here is a good example of the Varsavia occultation observed in the USA on July 18, 2003 analyzed by D.W.Dunham where 41 observers data was used to create the profile. Each numbered line represents a single observer’s contribution to the development of the shape of this asteroid. Your contribution is uniquely valuable to the understanding of these bodies. We are continually working to study the composition of asteroids that are typically located at an average distance of 150 million miles from earth. Since asteroids are irregular in shape and have rotation periods on the order of hours, one occultation observation can produce an instantaneous profile which would be different were the occultation to have occurred and been recorded an hour later, for example. Here is an example of close up views of the asteroid Itokawa which is just 490 x 180m (1617 x 594 ft) in size. While models tend to fit occultation timings to a typical elliptical shape, it is easy to see that this is only an approximation and that those observations that do not fit the model accurate may be real manifestations of an irregular form.
After selecting an event, be sure to scroll down to the REFERENCE DATA to see 1) safety tips, 2) sample occultation timeline, 3) basic info on how to observe an occultation, 4) how to determine if the weather will allow you to see the occultation. For the maps below, the green line represents the CENTER of the predicted path; the blue lines are the predicted northern and southern edges; the red lines are the error limits in both directions. These predictions are not absolute but should be fairly reliable and in many cases very reliable.
Columns are defined as follows:
UT DATE TIME: date and time in Universal Time
ASTEROID: name of asteroid
DIAM: approximate diameter of occultation path
DUR: duration of occultation in seconds
DM: drop in brightness
MR: magnitude in Red
DIS: distance of star to be occulted from the Moon
M%: percent Moon illuminated
PLACE: general region where occultation might be observed
ALT: elevation of the star in the PLACE
AZ: azimuth of the star in the PLACE
SUN: elevation of Sun below horizon
I: issue where 1 = low elevation; 2 = distance from Moon; 3=Moon phase; 4=proximity to sunrise or sunset; 5=low drop in brightness; 7=double star involved increasing likelihood of path error; 8 = small asteroid
UT DATE TIME ASTEROID DIAM DUR DM MR DIS M% PLACE ALT AZ SUN I
08/15/14 053225 Armida 152 23 1.7 12.5 107 74 Waco/Big Bend 29 215 -43
08/19/14 040252 Alexandra 160 28 0.6 10.7 155 34 El Paso 32 181 -28 5
08/24/14 101159 Lampetia 134 33 0.8 10.9 130 1 El Paso/Amarillo 64 241 -24
08/25/14 030857 Lamberta 190 35 0.7 12.3 125 0 Houston 23 146 -28 5
08/25/14 025532 Laetitia 240 35 0.3 12.0 125 0 Beaumont 45 196 -27 5
09/06/14 080400 Minerva 228 16 3.2 9.7 119 89 El Paso 37 78 -49
10/04/14 063949 Dysona 81 6 3.2 11.5 93 77 N. of Waco 69 41 -62
10/04/14 105041 Hedda 65 5 2.6 11.9 134 79 N. of Waco 78 116 -21
10/11/14 095929 Euryanthe 55 5 6.1 9.2 45 89 Waco 59 112 -32
10/12/14 075959 Hypatia 169 12 1.8 11.7 35 82 N. of Dallas 31 100 -54
10/16/14 015738 Xanthippe 153 11 1.7 11.8 126 47 West TX 49 120 -22
10/16/14 052036 Irmintraud 87 7 1.7 11.4 86 46 West TX 78 77 -63
11/09/14 102406 Charis 51 10 5.4 9.3 15 93 Houston 69 231 -30 3
12/05/14 021637 Juewa 170 15 0.5 12.2 34 98 Houston 34 60 -37 5
12/13/14 111658 Leukothea 115 8 1.2 11.2 161 2 Victoria 45 292 -24
12/24/14 090605 Fama 37 3 5.6 8.1 167 7 Houston 72 255 -52
12/29/14 113107 Urhixidur 79 6 3.4 10.4 96 58 Corpus Christi 47 311 -24
Maps for the following events showing the area of visibility may be found at:
by selecting either CURRENT or FUTURE EVENTS tab.
|JOELLA||JAN 5||9.2||4.6||4.3||21||100||NORTH OF|
|EURONYME||FEB 27||12.4||3.5||1.4||170||67||NORTH OF|
|THUSNELDA||MAR 8||9.2||3.1||4.9||111||95||NORTH OF|
|PROKNE||APR 4||10.4||16.9||1.5||52||100||WEST OF|
|ARA||APR 6||11.4||3.5||1.6||82||96||SE TX||0.88|
|THEMIS||APR 30||10.7||39.6||1.4||90||87||SAN ANTONIO|
|POMONA||MAY 1||9.6||28.8||2.4||88||93||BTWN SAN ANTONIO|
|TURANDOT||MAY 29||8.4||2.7||5.8||175||82||NORTH OF|
|IO||JUN 2||12.3||42.9||1.0||62||100||LA OR S. TX||0.40|
|KEMPCHINSKY||AUG 14||6.8||1.6||9.8||99||0||S. TX||3.12|
|LUDMILLA||OCT 5||8.7||2.2||3.9||21||45||N. TX||0.88|
|AIDAMINA||OCT 14||12.0||8.1||2.1||159||2||SAN ANTONIO||1.56|
|FELICITAS||DEC 5||11.6||5.3||1.5||166||34||N. TX||0.48|
To sign up for observation, contact Paul Maley: email@example.com
BEST RECOMMENDED EQUIPMENT TIPS
I recommend either a Celestron 8 or Meade 8 + f/3.3 corrector lens and multiple eyepieces for visual observation. You must also have a tape recorder and short wave radio source of time signals. The telescope should be on a motor driven mount and preferably be operable in the field so 110VAC power is not required. For video work, we recommend the Supercircuits PC-164 camera. Under good conditions and this set of optics you can visually see or videotape stars to +12 magnitude. A digital short wave radio that can receive 5.0, 10.0 and 15.0 MHz with an audio out jack. I recommend the Eton G4000A which can be bought online for less than US$100. To boost your ability to receive time signals, it helps to attach about 20 ft (6m) of antenna wire to the antenna of your receiver. To record video, you can use a camcorder that can accept VIDEO IN and AUDIO IN so you can directly route time signals and video and record both simultaneously. Warning: some newer DV models and some brands of camcorders do not have this feature. Always verify before purchasing. Avoid GO TO scopes unless you are really proficient with one. You should also be able to manually star hop to a target star. A GPS is useful for finding a precise spot since we need your coordinates measured to the nearest second of arc. BASIC INFORMATION ON HOW TO OBSERVE AN ASTEROID OCCULTATION See introductory information on what is an asteroid occultation, what can be learned from it at: GENERAL INFO Report occultations electronically through this form link. See: REPORT FORM. HOW TO USE A LINE MAP Line maps are lines drawn parallel to the center of the asteroid occultation path. They are equally spaced and are set up both north and south of the track. Each line can run a couple of hundred miles. One observer and one observer only is assigned a line and no one else is allowed to occupy it. That way, each observer can contribute a unique set of data. In the example below line N-10 is shown. The observer should always try to get within a half mile of the line, if not exactly on it. In searching the area look at A (small road where it turns to an L shape), B (road circle), C or E (ends of a road), D, E (another small road intersect). Avoid roads like 183, hwy 59 and 961 which are major roads. A GPS is needed to record the precise coordinates of the site.
You must observe according to standard protocols and watch/record the star without interruption for a 4-minute window centered on the predicted time of occultation. See: VISUAL VIDEO METHODS or VIDEO METHODS
SAMPLE OCCULTATION TIMELINE
Take any prediction and use the following timeline: If your experience at finding stars is not extensive, locate the target star in the days before the event. The most common mistake is to either be set up on the wrong star or to wait too long to set up and thus you cannot find the star in time. 12 hours before (predicted time of central occultation): be sure you have checked out all equipment and that it is operating. In SE Texas always use a dewcap and heater if you have exposed objective lenses or corrector plates. Even in winter, dew will form. If you can power a hair dryer, it will save the day. If none of these are available, a last resort is to pullyour scope off the mount, move it into your car and use the car heater to blast hot air on the lens surface. Be sure you have enough time to realign the scope and so that dew won’t form before you record the occultation. 2 hours before: be on station at your selected site. Use a GPS to record longitude/latitude of the site; if you are at someone’s house, I can compute the longitude/latitude if you send me the address. 30 minutes before: acquire the star no later than this time 20 minutes before: if visually observing, run a test to be sure your voice, shortwave time signals record properly. If not, reposition them and run another test until time signals and voice record evenly. 2 minutes before: begin nonstop observation/recording. Call out ‘D’ when the star disappears (or ‘out’); call out ‘R’ when it reappears (or ‘back’); note your reaction time for each call-out. 2 minutes after: end nonstop observation/recording within 24 hours after: send email to firstname.lastname@example.org reporting results while details are fresh CLEAR SKY CLOCK–THE EASIEST WAY TO DETERMINE IF IT WILL BE CLEAR
ASTEROID OCCULTATION PREDICTIONS WORLDWIDE
: For advance warning of impending asteroid occultations consult the PREDICTIONS site by Steve Preston who has also kindly supplied many of the maps on this web page. When you view that site, do not be confused by the RANK number given to any event as this number does not necessarily correlate to my scale above.Another terrific site that features interactive maps that you can customize to fit your site is from Charlie Ridgeway that is now hosted by Derek Breit. You can create a map with any related line with respect to the occultation centerline and also search to find the best sites along and near the line including my favorites: airports, cemeteries, churches, levees and parks. See: OCCULTATION MAPS. The format of this site changes frequently but it does have maps for all asteroid events for the year. Also, be sure your internet browser is compatible with this software or it will not function properly.
BSERVATIONS OF ASTEROID OCCULTATIONS I HAVE MADE TO DATE:
My personal table of successfully observed minor planet occultations can be viewed at OBSERVATIONS MADE TO DATE.
HISTORICAL SUMMARY OF ASTEROID OCCULTATIONS
BINARY ASTEROIDS KNOWN TO EXIST
See: BINARY ASTEROID LIST
SOLAR ECLIPSE EXPEDITIONS
If you think this is fun, see our SOLAR ECLIPSE TOUR PLANS
I observed this event from near Travis, Texas and recorded an unusual flash just after the star disappearance. After having attempted about 1500 occultations up to this point, I have never seen such a phenomenon. The graphic below shows the spike using the program LIMOVIE just before frame 233. The data was reduced by R. Venable from the original 8mm tape and the flash is quite prominent on the video.
DECEMBER 13, 2006 (70) PANOPAEA The occultation of the 8.6 magnitude star TYC 1231-01469-1 by the asteroid (70) Panopaea is depicted in this presentation calculated by B.Timerson. This event was well predicted by Steve Preston and occurred on December 13, 2006. Eleven Texas observers were part of the team. The letter (M) indicates no occultation was seen. Results show the asteroid appears to be nearly spherical in shape at this specific aspect as seen from the earth.
JANUARY 5, 2006 (466) TISIPHONE (THURSDAY MORNING)
This occultation was successfully observed along Hwy 59 in the vicinity and north of Victoria, TX very close to the most recent prediction. See initial summary report below.
BACKGROUND: A 9.2 magnitude star was occulted for up to 8 seconds by the 72 mile wide asteroid (466) Tisiphone south of Houston. The map below shows the north and south limits between the green lines and the error bars as red lines. RESULTS
A front pushed clouds into the Houston-Victoria area and was slow to clear. However, by 4am most clouds had existed the area leaving a few cirrus patches which did impact some observers. The plan was to have mobile observers drive into the lines between S7 and N7 which had the highest probability of seeing an occultation. Errors in the prediction were expected to push possible observations as far north and south as N12 and S12. As it turns out, 8 observers did successfully record the event. The longest chord was reported by Charlie McLeod at 8.44 seconds, his first occultation, which was captured on video. As luck would have it Rick Frankenberger of San Antonio timed a 4.6 second event from close to the southern limit and Dennis Borgman from the George Observatory videotaped a 4.76 second event on the north side of the path. The next station north from Dennis was Triple Nickel, making his first ever attempt using an 8-inch Dob. He clearly reported no occultation. It appears then that the actual north edge was in the 5 mile gap between Borgman and Nickel.
A similar suggestion is that the actual southern edge must have been in the 5 mile zone south of the Frankenberger site. This is to be considered a highly successful experience and congratulations are in order to the above observers and Paul Sventek, Richard Nugent, Dave Clark and Matt Delevoryas who also timed the occultation. Thanks also to the entire team who braved the weekday morning to get up and attempt this event. Those who made negative observations should clearly see that your work is very valuable! Special appreciation is extended to Fletcher Gray who made a special trip to Victoria 3 days early to scout for good sites in addition to having returned a second time for the event; thanks to Debbie Moran and Doug Rask who also drove long distances into the path. Due to the rare nature of the predicted track appearing to have altered due to a possible perturbation by another asteroid (at least that is the theory), it is hoped that this detailed information will help not only to shed some light on that problem, but also confirm that the size of Tisiphone was a bit larger than had been forecast.
This was also a case where the consistent nature of the negative sightings was very important. The fact that we could easily determine the upper boundary of the northern edge of the true path was only made possible by having evenly spaced dedicated observers. We had at least two cases where brief dimmings were seen but other observers who were at virtually the same chords did not confirm them; hence we can chalk these up to passing cirrus. Lessons were learned from this experience especially for those who had not observed an occultation before and those who had not observed one in a long time: be sure to give yourself enough time to find the star; if using a GOTO scope, be sure you have enough alignment stars visible in case of cloud; finding the star field east of the meridian and then attempting to relocate it when it has moved to the west side can cause you to get disoriented due to the changing aspect of the star pattern. The first graph below shows a preliminary solution that I generated.
The fit is not perfect and this should be refinable later on. Though the model shows Tisiphone as an egg (grade AA perhaps?), the fact that the lengths of each chord do not match the shape is not unusual. No asteroids would conform to a precise geometric shape due to their irregular makeup. It also shows that the rotation of the asteroid is important in determining how many observers actually see the occultation. Were it to have passed centrally over Houston we might have 20 or more observations and excellent resolution of the form due to the close observer spacing in the city. The graphic also shows the great value in being assigned a line. If all lines are staffed then we can get complete and accurate coverage across the face of the asteroid. Where the lines are thickest means two observers were literally on top of each other with respect to the ground track because they could not move.
N27 K.Drake (1)——-No occultation ……
W.Aulenbacher (6) (Austin area)–No occultation ……
S.Barziza (2)——-No occultation N20
S.Sartor (3)——–No occultation N19
P.Nolan (4)——–No occultation ……
B.Cudnik (5)——-No occultation N15
D.Rogan (7)——-No occultation ……
B.Dillon (9)——–No occultation ……
C.Shaw (8)———No occultation ……
M.Knewston (10)–No occultation ……
L.Binder (11)——-No occultation ……
W.Whiddon (26)—–No occultation N14
T.Lawrence (12)–No occultation N13
B.Tobias (San Antonio) — No occultation N13
T.Nickel (13)——No occultation N12
B.Taylor (14)——Clouded out ……
D.Borgman (14)—4.76 second occultation N9
P.Sventek (16)——7.5 second occultation N8
M.Delevoryas(25)–7.1 second occultation N7
D.Moran (17)——-no data N6
C.McLeod (18)—–8.44 second occultation N5
D.Clark (19)———8.37 second occultation N4
P.Maley (20)——–7.85 second occultation N2
F.Gray (21)———-no data N1
R.Nugent (22)——-7.47 second occultation
C. D.Rask (23)———-no data S2
R.Frankenburger (24) (San Antonio)–4.6 second occultation
DECEMBER 11, 2005 (628) CHRISTINE (Sunday morning): RATED PG
A 12.9 magnitude asteroid passed in front of a 11.2 magnitude star for up to 5 seconds in the Houston area. Four chords were obtained, 3 observers missed because they were just outside the path, and 2 other observers were fogged in. Richard Nugent graphed the data as provided by Brian Cudnik, Dave Clark, myself and Richard. Thanks also to Doug Rask, Dana Lambert, Fletcher Gray, Ken Drake, Paul Sventek, and Steve Linscott who also tried for this event. Luckily the sky cleared about 2 hours before hand but there were fog patches in a few places and some bands of cirrus that skirted through. The graph below depicts the results.
AUGUST 13, 2005 (89) JULIA (Saturday morning)
A 7.6 magnitude star was eclipsed by Julia for up to 11 seconds. I flew to Regina, Saskatchewan on the night of August 12 arriving 1030pm. The occultation was at 3am the next morning. Skies were generally clear though clouds kept forming to the northwest. I set up at the predicted centerline about 50km west of Regina airport. As the clouds kept coming in I had to move, changing sites no less than 7 times. Finally within 30 minutes of the event I settled on a site about halfway back to the airport and set up my video equipment. The equipment failed and I had no choice but to use 7×35 binoculars and a tape recorder to attempt the occultation. This worked well because skies were clear and dark. Two unexpected things happened. An aurora to the north extending about 15 degrees above the horizon began as a curtain around 11pm, then fell back to a broad glow with stars clearly shining through it.
AUGUST 24, 2004 (11) PARTHENOPE (Tuesday night)
This occultation crosses all of the Houston viewing area and has an excellent path accuracy; the star is magnitude 11.7 but the drop is only 0.21 magnitudes. Also the 69% sunlit moon is just 17 degrees away at 8:38pm. Well, maybe it is not that hard except for one more black mark. The sun is a mere 11 degrees below the horizon here, meaning you have little time to acquire the target area after sunset! However, I have already simulated this and found that I can spot the bright stars close by the area 20 minutes before the occultation in 7×35 binoculars. I rate this as M mainly because of the short time to find the field and the very low magnitude drop. Visual observation is not recommended. But the use of video may prove to be successful. A very clear sky is needed. The reward is an exceptionally long occultation of up to 74 seconds. This is typically nearly 30 times the duration of a typical minor planet occultation. RESULT: I was successful 6 miles west of Alvin, TX in capturing about a 63 second event with my manually pointed C8, Collins I3 and Watec camera. I still cannot believe it all came together. Anyway, with a rented car I found a site about 5:00pm and waited until the sunset before I began scanning the sky for Polaris. At 8:15 I found it and at 8:29 I was on the star, just 9 minutes before the predicted time. However, from my video tape I believe the disappearance occurred very early and was very indisinct. The reappearance also was less indistinct. The tape will be analyzed photometrically. As far as I know this was the only observation.
JULY 17,2004 (41) Daphne (Saturday night) ALMOST GUARANTEED TO BE SEEN FROM HOUSTON
Result: I was successful in videotaping a 16.5 second occultation from Friendswood. Even though the magnitude drop was only predicted to be 0.34, I was surprised to easily see the drop on the small Sony camcorder monitor. I used my standard setup: Celestron 8, Watec video camera, and Collins Image Intensifier. At first I set up a site at JSC but thunderstorm tops could be seen low in the northeast. The forecast had predicted development of evening storms and movement was north to south; I abandoned the JSC site and thought about driving to Victoria but realized that just going about 10 miles west might be enough. At 11pm outflow from the thunderstorms was seen moving from the northeast in the direction of the star field but fortunately the cirrus stayed about 30 degrees away at occultation time. Observations were attempted by an NHAC group (Dave Clark et al.) northeast of downtown Houston but were clouded out by thunderstorms. Doug Rask at Seabrook also was victimized by cirrus from the same storms. Lesons learned: check the Clear Sky Clock web page for the site you are anticipated observing at; or, watch cable channel News24 in the Houston area (Time Warner) which has weather on every minute ending in 7. They show a model of cloud cover 24 hours ahead of time and it is generally a good predictor of weather patterns. Be mobile and ready to move to another location.
DECEMBER 31, 2003 Lacrimosa (Wednesday morning) NORTH SIDE OF HOUSTON
RESULT: Relatively good coverage was set up for the small asteroid. Five observations were made by Texas observers; 10 other observers unfortunately reported misses or, in one case, cloud. The maximum event time was expected to be 5.2 seconds but the maximum observed occultation of 5.62 seconds seen close to the predicted center line indicates the size of Lacrimosa is about 8% larger than predicted (equatorially), and that the prediction itself was relatively good. A small north shift is shown to have occurred based on the reports. Two common problems were experienced again and it is important for observers to be aware of them: 1) one observer observed the incorrect star, 2) dew formed mandating that observers in this part of the country, even in our winter months, should always carry a dew removal device like the Orion Dew Zapper or a portable hair dryer. A dew shield helps but doesnt always work by itself. I recommend not setting up your equipment earlier than 1 to 1.5 hours before the event. Here is the list of observers reporting in. Kudos to the entire Lacrimosa observing team! 1.Kenneth Drake, 8 inch scope, visual reported a 2.5 second occultation 2.Beth Turner, Meade 8, PC164 video recorded a 5.03 second occultation 3.Paul Sventek, 10 inch scope, visual reported a 5.0 second occultation 4.Paul Maley, C8 scope, Watec camera, Collins I3 reported a 5.62 second occultation 5.Tim Kenyon, 10 inch scope, visual reported a 4.7 second occultation Other observers reporting included: 1.Loyd Overcash (Ft. Davis) – cloudy 2.Mike McCants (Austin) – Miss 3.Sam Barziza (Houston) – Miss 4.Richard Nugent (Houston) – Miss 5.Doug Rask (Houston) – Miss 6.Aaron Clevenson (Houston) – Miss 7.Keith Rivich (Houston) – Miss 8.Walter Aulenbacher (south of Austin) – Miss 9.Larry Mitchell (Houston) – Miss 10. Brian Cudnik (Houston) – Miss Special recognition is given to 15-year old Beth Turner of the Woodlands who made her first observation and also obtained a complete video recording of the Lacrimosa asteroid occultation. She is perhaps the youngest person historically to have ever observed one of these events. Having become interested in observing the sky at a very young age, she received a telescope a little more than one year ago and is now proficient in its use. The photo below shows Beth and her equipment set up for an occultation. Photo by E.Turner.
DECEMBER 24, 2003 Circe (Wednesday morning) SOUTHWEST OF HOUSTON
The most potentially accurate path of 2003 has now been predicted to cross Refugio, Beeville, and Three Rivers centrally with the north limit over Victoria and Pleasanton, south limit at Corpus Christi, Robstown and Freer. It occurs at 3:00am local time on Wednesday morning December 24 (Christmas eve day). All observers in south, central and east Texas are requested to consider this exceptionally favorable event involving 70 mile diameter asteroid Circe and a 11.8 magnitude star. It takes an 8-inch scope to see this one and video with a PC164 camera is recommended. With an uncertainty of 1/4 path width, predictions don’t get much more accurate than this. The star will be 60 degrees above the WSW and there is no moon about. This is Christmas eve Day, one week before the Lacrimosa event Dec. 31. The magnitude drop is 0.8 and this should be easily visible in your telescope/video.
RESULT: Attempted observations were made by Paul Sventek, Larry Mitchell, Charlie McLeod, Paul Maley and Richard Nugent. Only Richard recorded the event with some certainty, logging about an 11 second occultation. The magnitude drop was supposed to be 0.8 but it appears the star may have been a little brighter than predicted and so this confused some observers. Given Richard’s location at N5 and the length of his timing, it would appear a slight north shift took place.
DECEMBER 21, 2003 Kassandra (Saturday evening) Tulsa Oklahoma
This prediction has me observing with the Tulsa Astronomical Society at their location near Mounds, Oklahoma. This site is estimated to be 20% of the way between the center line and southern limit of the occultation path. An 11.8 magnitude star is to be occulted there for up to 8 seconds. Art Lucas is to observe with his C14 and PC164 at Stillwater near the predicted north edge.
RESULT: A sizable north shift occurred and Art and another observer in Missouri observed an occultation while I observed a miss at Rocky Keys observatory southwest of Tulsa, using a Meade 14, the Watec camera and Collins I3. Richard Nugent observed a miss near the predicted southern limit from Anderson, TX.
DECEMBER 13, 2003 Vindobona (Saturday evening) ARIZONA
An 11.2 magnitude star will be occulted by 14.2 magnitude (231) Vindobona from north of Prescott to Flagstaff in the early evening of Dec. 13. I plan to observe in the Sedona area using a C8 with Rick Schaffer of Sedona. The prediction is on the order of that of Thyra so a shift of some sort is likely.
RESULT: SUCCESS! Using a Meade 12 inch GOTO scope, along with its owner Fulton Wright and Rick Shaffer, a former Astronomy Magazine columnist, we observed a 2.64 second under incredibly dire conditions. Lynn and I drove 130 miles from Scottsdale to Mountainaire under total overcast cirrus arriving less than 3 hours before the event. Our site was at 7000 ft elevation. Unbelievably, as we waited thinking “what are we doing here?”,we could see one or two stars. Then the clouds thinned enough for Fulton to perform a 2 star alignment and eventually we could see the 11th magnitude target star as it got about 30 degrees above the eastern sky. One bright Geminid meteor flashed by but the cirrus would not go away. Temperatures dipped to freezing and worries about frost persisted as well as loss of battery power. I used my Collins I3 and Watec camera to sight the star 38 minutes before the occultation. Had we used Rick’s C8 it would not have worked because the cirrus was just too much of a problem. Luckily the M12 had great tracking and Fulton had actually located the star the night before and I verified it in real time. Our site was located about 7 miles south of the predicted path. About 7 seconds before the predicted time the star winked out for about half of the maximum predicted duration. All of us watched it in real time on my camcorder monitor. No secondary events were seen; however, the cirrus affected the target in worsening fashion in the minutes following the occultation. Then as we packed up to head home the sky really did clear. This was one of the hairier expeditions and for any number of reasons it almost did not happen. The photo below shows Rick’s Dodge van and Fulton’s M12 along with his makeshift dew cap. Left to right Rick, Paul, Fulton. Photo by Lynn Palmer.
I videotaped a 1.83 second occultation of an 11th magnitude star by 12.3 magnitude asteroid (115) Thyra from Arizona City at the home of Hazel and Dick Lawler. They have a Meade 10 and a Galaxy 20 inch Dob. Through the courtesy of Steve Dodder I was able to use his C8 and my Watec camera and Collins I3 to videorecord this occultation with the full moon present and the star at an elevation of only 22 degrees. Skies were cloudy to the north and nearly moved in on my site. Luckily the cloud bank kept just north of the area and skies remained clear enough to see the event. The path shifted less than one half path width (25 miles). Luckily for me it was toward my site although it unfortunately left Derald Nye, James McGaha, Jim Stamm, Randy Peterson (with Don Wrigly and John Matthews) with no event. However, because of jet lag, I did not check my audio connection which apparently was not working, so the absolute time of the event was lost. The overall duration was evaluated quite accurately using Derald Nye’s time inserter.
OCTOBER 23, 2003 Aidamina(Thursday evening) West TX, New Mexico: RATED PG RESULTS: SUCCESS!
8th magnitude star occulted by the asteroid (978) Aidamina for 6 seconds over W.Texas and New Mexico. The diagram below developed by David Dunham illustrates the result. This marks the first time an asteroid occultation was observed by local observers from the Rio Grande Valley of Texas (Paul Gabriel/Mike Mills). Not all observers who set up are shown. Included are Cory Stone (6 miles south of my site), Blayne Primozich and Ken Snelson (23 miles south of my site) who had a miss due to the north shift of the resultant path. Cory took the lead in pulling together the El Paso observers. The dashed lines correspond to the orientation of the axis of the asteroid; the software fit is to a triaxial ellipsoid. A great effort by the El Paso team in addition to the New Mexico observers. My own timings using Tony Nelson’s Celestron 11 were recorded on video and the tape reveals the 13.5 magnitude asteroid during the occultation. Legend: 1. David Dunham at Yeso Hills, NM 2. Paul Gabriel, Mike Mills at Roma, TX 3. Richard Nugent at Balmorhea, TX 4. Paul Maley, Tony Nelson at Guadalupe Mountains, TX 5. Thomas Dorman at Guadalupe Mountains, TX 6. Steve Preston at Goldendale, WA 7. Robert Eramina at Seattle, WA 8. Mark Vincent at Socorro, NM 9. Mark Komsa at Sunspot, NM 10. Peter Armstrong at Ft. Davis, TX 11. Patrick Wiggins at Toole, UT 13. Blayne Primozich, Ken Snelson at Guadalupe Mountains, TX
Houston would see a low pass of this historic 22-hour manned flight at 6:28 am with Shenzhou 5 reaching a maximum elevation of merely 8 degrees above azimuth 346. Tough to see in our skies. RESULT: SUCCESS! I flew to Dallas at 10pm October 14 (two hours after the liftoff of Shenzhou 5, the flight of the first Chinese taikonaut Yang Liwei), and drove north to Gene Autrey, Oklahoma. I was in position at 5:30 am near an oil well at Gene Autrey, Oklahoma. I first videotaped the decaying Shenzhou 5 rocket body, 145 miles high, at 6:25am on October 15 as it came out of the earth’s shadow less than 20 degrees above the northern horizon. The rocket was tumbling slowly with 10.3 second intervals between maxima. Then at 6:28 an object appeared at the appropriate place in the sky which almost fooled me into thinking it was the manned capsule Shenzhou 5. Instead it was Cosmos 1675 rocket moving slowly in nearly the same direction, passing close to Iota Cepheus. Luckily I recognized the slight difference in orbital motion and just 30 seconds later, Shenzhou 5 itself appeared 212 miles high and passed within 1/2 a degree of the russian space junk. I was able to track it for about 2m 37 s. The video was delivered to CNN in Dallas before I flew back to Houston. About a week later I learned CNN showed it. I also took a time exposure photo on ASA400 film and the track of K1675R and Shenzhou 5 appear dimly on the print.