*** ASTRONOMICAL EVENTS FOR HOUSTON, TEXAS ***

DECEMBER 22, 2006 (547) PRAXEDIS (THURSDAY MORNING)

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): RATED PG

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.

For details and start charts, see Details.

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.

Here is another representation by Richard Nugent of the same data.

The following is a list of the observers who reported following the occultation. The numbers to the left are the line map relationships. The number in parenthesis is the line on the graph above. First you can see what unfortunately happens when 6 observers are fixed and cluster together--the lines just merge revealing a large gap between the line cluster and upper 5 obsevers. The 3 lines touching just the right side of the figure (from top to bottom) correspond to D.Moran, F. Gray and D. Rask positions if they had obtained data. The unbroken lines show observers who saw a 'miss'. B.Tobias position was north of T.Nickel and due to a program plot problem does not show on the graph. B.Taylor's position is the same as Borgman's.

• 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): RATED X

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 7x35 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.

This is an aurora observed in August by the STS-114 crew. From the green arc structure it is almost identical to what I observed from Regina.

The aurora continued all night though clouds covered much of that area from time to time. Also, the Perseids were seen like never before. Classic fast moving meteors of either -1 or +4 magnitude with some in between, the whizzed across the sky leaving brief smoke trains. The longest train lasted 6 seconds. I could see one now and then driving down Highway 1 toward Moose Jaw. It had rained earlier in the day and the moisture content of the air was quite high.

Result: Success! I recorded about a 9 second occultation at my site. Five or six others were successful from the US though most areas were shrouded in cloud. Upon returning to Houston I learned that auroral activity was quite high for that period and continued through August.

AUGUST 24, 2004 (11) PARTHENOPE (Tuesday night): RATED M

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 7x35 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: RATED PG

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: RATED PG

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.

The following is a reduction of the observations provided by Richard Nugent. The observer coverage was well laid out with only a gap in the two southern observer groups. This was due to the holidays and not having as many persons in the Houston metro area online as we had hoped. Mike McCants definitely reported no event and assuming the shape is as the plot indicates, he was 3.5km from the true south edge. Doug Rask was the northern-most observer who reported a definite miss. The good agreement of the four chords is testimony to the observers and their ability to recognize what was happening. Brian Cudnik reported two brief momentary 'twinkle' events. Since he was outside the asteroid path it is not possible to confirm them. At least four separate video systems were used by the team mostly using the Supercircuits PC164 camera.

---------------------------------------------------------------------- TIMELINE on DECEMBER 30 AND 31 (all times are CST)

11:00PM TUESDAY NIGHT. Arrive at site and begin set up.

12:30am WEDNESDAY MORNING. Conduct test to assure your radio and voice record evenly. Verify you have the correct star by checking from two directional approaches.

12:59am Begin nonstop observing/recording. Look for any and all brightness changes in the star no matter how brief.

1:01:43am Expect an occultation lasting up to 5 seconds to be seen.

1:05am Stop observing/recording. Do not leave the site until your position has been accurately noted (or recorded with GPS).

Within 24hours, send an email to pdmaley@yahoo.com indicating results (positive or negative) and your latitude/longitude, estimated timing errors.

DECEMBER 24, 2003 Circe (Wednesday morning) SOUTHWEST OF HOUSTON: RATED X

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: RATED X

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: RATED PG

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.

DECEMBER 7, 2003 Thyra (Saturday evening) ARIZONA: RATED PG

RESULT: SUCCESS! 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: