Centennial Observatory - Research

Research at the Centennial Observatory

Although the primary purpose of the Centennial Observatory is to provide visitors with opportunities to experience the universe visually through telescopes, the facility is also used for astronomical research.  The main research program determines asteroids' sizes and orbits via stellar occultation.  The method is straightforward: Timing how long a passing asteroid blocks (occults) the light of a distant star, together with the asteroid's previously-determined distance and speed, allows its diameter to be calculated (by distance = rate x time).  With multiple observers at various locations around the globe, the size and shape of the asteroid's shadow (identical to that of the asteroid itself) may be mapped out.

Due to the inherent uncertainty in asteroids' orbits, the paths of their shadows on Earth, cast by starlight, are imperfectly known.  While many observers utilize small, portable instruments which allow them to travel to locations where a given asteroid's shadow is likely to pass, this option is not available for the Centennial Observatory's permanently-mounted 24" (0.6m) telescope.  Therefore, many occultations, including ones with a low probability of being seen by our telescope, are observed to increase the frequency of success.

The Centennial Observatory's first asteroid occultation observation was conducted on 24 August 2012, when asteroid (1585) Union cast its shadow from the star TYC 5777-010444-1 onto the Earth.  No occultation was seen (i.e. the shadow missed Twin Falls).  All subsequent "positives" (timings performed when the Centennial Observatory was in an asteroid's stellar shadow) are listed below, in reverse chronological order.

Click on the date for a map of the asteroid's predicted shadow path.  Click on the asteroid name for a profile of the asteroid showing all observers' chords (star tracks relative to the asteroid as seen from different locations).  Click on the star name for a graph of the photometric data.  Click on the observers' names for a map of all observers' locations.  (Use the "back" button to return to this page.)

DateAsteroidStarProb.Observers*Notes
06 Oct 2017 (1936) Lugano TYC 1358-00407-1 31.1% C. Anderson
28 Sep 2017 (69) Hesperia 4U 380-139928 99.9% C. Anderson
K. Hansen
26 Sep 2017 (372) Palma UCAC4 697-043370 100.0% C. Anderson
09 Aug 2017 (903) Nealley TYC 5788-00046-1 66.8% C. Anderson
16 Apr 2017 (838) Seraphina 4U 475-43580 31.8% C. Anderson
K. Hansen
K. Hansen
11 Apr 2017 (105) Artemis HIP 62736 26.3% C. Anderson
Etc.
18 Jan 2017 (52) Europa 2UCAC 28031948 99.9% C. Anderson
22 Oct 2015 (247) Eukrate TYC 3413-01493-1 57.3% C. Anderson
S. Barksdale
23 Aug 2015 (107) Camilla TYC 5595-00982-1 88.0% C. Anderson
B. Hall
J. Royalty
Cited in Astronomy & Astrophysics, 7 Feb 2017
27 Jul 2015 (8823) 1987 WS3 HIP 90382 2.2% C. Anderson
B. Hall
Only occ. of this asteroid ever recorded.
12 Feb 2015 (931) Whittemora TYC 652-01042-1u 14.2% C. Anderson
D. West
09 Oct 2014 (54) Alexandra TYC 6308-00865-1 Not rec. C. Anderson
*At the Centennial Observatory.  Observers in other locations not listed.