On December 13, 2013 at 10:26:26 (UT) asteroid (56) Melete occulted star 2UCAC 35905485 in the constellation Monoceros and was video recorded from my location in Gardnerville, NV. According to Wikipedia, Melete is a large and dark main belt asteroid. It is a rather unusual P-type asteroid, probably composed of organic rich silicates, carbon and anhydrous silicates, with possible internal water ice. It has a diameter of 134 km and a visual magnitude of 13.0. Melete was discovered by Hermann Goldschmidt from his balcony in Paris, on September 9, 1857. It’s orbit was computed by E. Schubert, who named it after Melete, the Muse of meditation in Greek mythology.

The occulted target star, for the event, is magnitude 13.1, and located on the northern edge of Monoceros. The predicted magnitude drop for the event was 0.7 with a maximum duration of 9.6 seconds.

At the predicted event time of 02:26 hrs (local) the skies were clear, temperature was 18 deg F and there was no wind. Final analysis of the recorded event, from my location, indicated a occultation duration of 8.782 (+/-) 0.107 seconds, and a “D” (Disappearance) time of 10:26:26.0136 (UT), (+/-) 0.053 seconds. The “D” time was approximately 2 seconds earlier than the predicted.

Below is the light curve for the event as generated by LiMovie and Excel.

The two images are annotated snippets of the star field from a recent attempt to record the occultation of 2UCAC 33330361 by the asteroid (418) Alemannia , from my location in Gardnerville, NV. The star 2UCAC 33330361 is 12.5 magnitude and located in Pisces. The asteroid (418) Alemannia is approximately 40km in diameter with a visual magnitude of approx. 14. The occultation event was predicted for Sunday, December 1st at 05:53:14 (UT) +/- 7 seconds. My location was about 40 km south of the predicted shadow center-line, and just outside the predicted shadow. The snippets are recorded at a sense-up of X64, at approximately 20 minutes before and 20 minutes after the predicted occultation. The actual occultation recording was made at X8 to improve timing accuracy. Magnitude drop was predicted to be 1.9 to 2.2 mag.
The path of the asteroid is from right to left in the images. Alemannia, at mag 14, can clearly be seen in the images as it approaches the predicted target star. Both the star and asteroid are also represented in the adjacent light intensity graphs from LiMovie.
Although the visual path of the asteroid appears to be directly toward, and away, from the target star in these images, an occultation event was NOT recorded from my location. James Bean recorded the same event in Carson City, and was within the predicted shadow. He also, did NOT observe an occultation.

First Draft

Where will you be this Friday evening at 10:07 Pacific Standard Time? The full RECON network is gearing up to observe an occultation by (176) Iduna!

Visit our campaign event page at the following link: (176) Iduna

Congratulations to the IOTA community for their tremendous effort in capturing a binary Trojan asteroid on October 21, 2013.  Shown below are preliminary profiles for Patroclus and its companion Menoetius.

Preliminary profile of binary Trojans asteroid

Visit http://www.asteroidoccultation.com/observations/Results/ for more details!

NOTE: No Diagonal used

The RECON was poised and prepared for our Mikhailov campaign last Thursday morning just after midnight.  From Fall River, California, to Gardnerville, Nevada, 11 inch telescope were all pointed to the target star field high in the southern sky.  Shown to the right are Warren and Red all set up on Portola, California.

Unfortunately, reports came in early from Gardnerville and Carson City that they were clouded out the entire evening.  Just as the event window opened, clouds from the same system reached Reno and Portola.  However, in the northern part of the network, the skies held and successful recordings were acquired by Fall River, Susanville, Greenville, and Quincy.

Given that predictions placed the shadows path in Carson City and Gardnerville, the weather got the best of this campaign effort.  However, in TNO occultation events (which we are practicing for) uncertainties will be greater and if the event had occurred in the northern part of the network, we would have captured it.  As with all ground based astronomy, we are always dependent upon the weather!

Clouds or no clouds, great job to all who were able to participate in this campaign!

We are excited for our second RECON campaign occurring this Wednesday evening/Thursday morning. The event is just after midnight, with Mikhailov’s shadow passing by the RECON network between 7:29UT and 7:33UT July 11.

For more details, visit the Mikhailov event on our observation campaign page.

We also encourage participants to provide updates on how the event is going by:

• Posting photographs to the TNO RECON Facebook Page
• Tweeting to #TNORECON
• Replying to this blog post

Good luck to all!!!  John and Marc

This past weekend, fifteen telescope sites associated with RECON coordinated to collect data from a predicted occultation by Pluto. The most recent predictions prior to the event placed Pluto’s shadow in the Southern Hemisphere, but this occultation provided a good inaugural opportunity for the RECON network. While we are still in the process of confirming data collected from the network, preliminary reports back from each site indicate both successes as well as lessons learned. Below is a summary of preliminary reports:

Six of RECON teams were able to successfully get on the Pluto star field and record data during the predicted times. Given the challenges of the Pluto’s location low on the eastern horizon, this is a significant accomplishment!

Two teams were able to record data but got on the field about 10 minutes late. This is not surprising because Pluto was just rising and was very low in the eastern horizon, so there was limited time to get on the field.

One team faced cloudy conditions but was still able to do a three star alignment through holes in the cloud cover. The team also did a “precise-goto” and got near the Pluto field and start their recorder, but the clouds never cleared in the target region.

The remaining six teams dealt with various issues both in and out of their control and were not successful in recording data but learned good lessons. These involved making proper adjustments to the camera gain control, re-centering the telescope on the target field, dealing with mountains and trees on the horizon that blocked the rising star field, fighting power failures associated with a design flaw in the power connection for the CPC-11, and explaining to concerned passers-by what folks were doing out with telescopes at 1AM.

All in all, things went very well for this first observation campaign. There were great lessons learned and with just a little more time and practice we would have had at least eight and likely even more scopes on the field for the event. Also, I just received email confirmation from Marc that the occultation was detected at Cerro Tololo Inter-American Observatory (CTIO) in Chile. Marc will provide more details next week when he is back from Brazil.

Great job all!!! Feel free to add additional details of your experiences as a reply to this blog post.