What does an asteroid occultation look like? Using video we can get a good idea. We consider the occultation of a 7.6 magnitude star SAO 060107 by the 76 km diameter asteroid known as (516) Amherstia. I travelled to Atlantic Beach, Florida on 14 January 2002 in order to capture this using a Collins Electro Optics image intensifier, Watec low light surveillance camera, attached to a Celestron 8 Schmidt- Cassegrain telescope. The seeing was not perfect but the occultation was clearly observed.
The first image below shows the "target star -- the brightest one in the field of view -- with the tiny image of the asteroid just to the upper right and almost appearing to touch it. This frame was taken 40 minutes before central occultation. The asteroid is magnitude 12.3. Visually, it would be easy to time the occultation of the star, but the asteorid would be too dim to detect in a typical sky condition.
My system attached to Tony White's (Tulsa, OK) Celestron 11. Arrow points to the connected unit from the SCT back of the C11. First, the f/3.3 focal reducer attached to the Collins I3, then the tiny Watec 902H.Photo taken 12/20/07 by Tony White.
For occultations of bright stars I use a 100mm f/2 Nikon lens and a light sensitive camera such as a Watec or PC164. This photo was taken at Varadero, Cuba March 15, 2008 after the successful occultation of a 6.3 magnitude star by the asteroid 241 Germania. Photo by Lynn Palmer
I have successfully observed and timed the following asteroid/planetary satellite occultations. However, you may ask why there is such a paucity of successes. Accurate ground track forecasting prior to 2001 was really poor, making successful observations problematic at best. You had to be really lucky in order to see an occultation. Beginning in 2001 many more events were being forecasted with improved accuracy, and astrometry (the science of astronomical position measurement) sources and reduction techniques experienced a major advancement. C8=Celestron 8-inch Schmidt Cass telescope in the table below. The M4 is the Meade 2045D telecope.
| NO. | DATE | ASTEROID/Solar System Body | STAR | METHOD | SITE |
| 115 | 8/21/10 | (16) Psyche | HIP 22112 | 50mm Mini (2) | CLEBURNE, TX |
| 114 | 8/14/10 | (404) Arsinoe | TYC 1340-02164-1 | C8 INTENSIFIED VIDEO | REFUGIO, TX |
| 113 | 5/16/10 | (276) Adelheid | 2UCAC43762516 | C11 INTENSIFIED VIDEO | HOUSTON, TX |
| 112 | 3/29/10 | (52) Europa | 2UCAC 39108118 | C11 INTENSIFIED VIDEO | HOUSTON, TX |
| 111 | 2/14/10 | (56) Melete | UCAC2 36090877 | C8 INTENSIFIED VIDEO | HOUSTON, TX |
| 110 | 2/5/10 | (191) Kolga | TYC 5636-00417-1 | 20inch + 80mm Midi | SIERRA VISTA, AZ |
| 109 | 12/25/09 | (81) Terpsichore | TYC 1795-00251-1 | 50mm Mini (2) | PATTERSON, CA |
| 108 | 12/24/09 | (216) Kleopatra | TYC 4909-00873-1 | 80mm Midi(2) | CASA GRANDE, AZ |
| 107 | 12/6/09 | (423) Diotima | TYC 1252-00803-1 | C9.25 | KINGMAN, AZ |
| 106 | 12/6/09 | (455) Bruchsalia | TYC 4682-02550-1 | C9.25 | KINGMAN, AZ |
| 105 | 12/6/09 | (348) May | TYC 5836-00670-1 | C9.25 | KINGMAN, AZ |
| 104 | 11/21/09 | (234)Barbara | HIP 34106 | 50mm Mini(5) | POLK CITY, FL |
| 103 | 10/24/09 | (164)Eva | HIP 10015 | 50mm Mini | LOXLEY, AL |
| 102 | 9/24/09 | (579)Sidonia | TYC 5273-00531-1 | C8+80mm Midi(2) | EASTLAND WA |
| 101 | 8/20/09 | (240)Vanadis | HIP75848 | 75mm Mini | NOME TX |
| 100 | 6/6/09 | (46)Hestia | TYC 6184-00208-1 | C8 VISUAL | CLEMVILLE TX |
| 99 | 2/17/09 | (185)Eunike | TYC 0193-00670-1 | 50mm mini (2) | QUINCY NM |
| 98 | 2/7/09 | (654)Zelinda | UCAC2 32019943 | M8 INTENSIFIED VIDEO | MADILL OK |
| 97 | 2/3/09 | (366)Vincentina | UCAC2 42749694 | C8 INTENSIFIED VIDEO | HOUSTON TX |
| 96 | 12/25/08 | (751)Faina | TYC 5267-00645-1 | C8 INTENSIFIED VIDEO | NAVASOTA TX |
| 95 | 12/8/08 | (402)Chloe | UCAC2 35357625 | C11 INTENSIFIED VIDEO | LIBERTY TX |
| 94 | 11/27/08 | (304)Olga | UCAC2 26590394 | M8 INTENSIFIED VIDEO | ENID OK |
| 93 | 11/15/08 | (1149)Volga | TYC 0543-01301-1 | C8 INTENSIFIED VIDEO | HOUSTON TX |
| 92 | 9/12/08 | (9)Metis | HIP 14764 | 105mm FL VIDEO | LAS VEGAS NV |
| 91 | 8/24/08 | (111)Ate | TYC 5803-01587-1 | M8 INTENSIFIED VIDEO | BRUDERHEIM, ALBERTA, CA |
| 90 | 6/18/08 | (19)Fortuna | TYC 6276-01878-1 | C11 INTENSIFIED VIDEO | BEEVILLE TX |
| 89 | 6/12/08 | (47)Aglaja | UCAC2 19792163 | C8 INTENSIFIED VIDEO | MAXWELL CA |
| 88 | 4/8/08 | (667)Denise | TYC 1401-00822-1 | M4 INTENSIFIED VIDEO | HORSESHOE BAY TX |
| 87 | 3/15/08 | (241)Germania | HIP 17026 | 100mm/fl VIDEO | VARADERO CUBA |
| 86 | 3/11/08 | (735)Marghanna | TYC 2936-00356-1 | M8 INTENSIFIED VIDEO | WINK TX |
| 85 | 2/28/08 | (429)Lotis | TYC 0191-00729-1 | M8 INTENSIFIED VIDEO | GARDEN CITY TX |
| 84 | 1/22/08 | (13)Egeria | TYC 0026-00627-1 | C11 INTENSIFIED VIDEO | CASA GRANDE AZ |
| 83 | 1/12/08 | (70)Panopaea | TYC 2501-00817-1 | 11MAK INTENSIFIED VIDEO | CRYSTAL NV |
| 82 | 1/2/08 | (24)Themis | UCAC2 38791508 | 24CASS INTENSIFIED VIDEO | CANEY OK |
| 81 | 12/20/07 | (187)Lamberta | TYC 2416-00772-1 | C11 INTENSIFIED VIDEO | DEWEY OK |
| 80 | 11/10/07 | (15)Eunomia | TYC 1930-00091-1 | M4 INTENSIFIED VIDEO | CALLAGHAN TX |
| 79 | 11/05/07 | (137)Meliboea | TYC 5739099761-1 | C11 INTENSIFIED VIDEO | ANGLETON TX |
| 78 | 10/26/07 | (203)Pompeja | TYC 1410-00470-1 | M4 INTENSIFIED VIDEO | FOREST LAKE MN |
| 77 | 9/09/07 | (704)Interamnia | TYC 2410-00061-1 | C8 INTENSIFIED VIDEO | BERNALILLO NM |
| 76 | 8/29/07 | (409)Aspasia | TYC 1327-00077-1 | C8 INTENSIFIED VIDEO | SWEENY TX |
| 75 | 7/20/07 | (153)Hilda | UCAC2 25791797 | M10 INTENSIFIED VIDEO | OTHELLO WA |
| 74 | 7/16/07 | (225)Henrietta | TYC 1065-00745-1 | C11 INTENSIFIED VIDEO | LAST CHANCE CO |
| 73 | 7/10/07 | (125)Nausikaa | HIP 92988 | M4 INTENSIFIED VIDEO | CALLAHAN, FL |
| 72 | 6/25/07 | (125)Nausikaa | TYC 7427-02638-1 | M4 INTENSIFIED VIDEO | WICKENBURG, AZ |
| 71 | 4/18/07 | (411)Xanthe | HIP 43103 | 100mm INTENSIFIED VIDEO | GREEN COVE SPRINGS, FL |
| 70 | 4/15/07 | (494)Virtus | UCAC2 42210347 | C8 INTENSIFIED VIDEO | CORDELE, TX |
| 69 | 2/18/07 | (55)Pandora | TYC 1421-00289-1 | M4 INTENSIFIED VIDEO | ENNIS, TX |
| 68 | 1/10/07 | (44)Nysa | TYC 1323-00422-1 | M4 INTENSIFIED VIDEO | LIBERTY CITY, TX |
| 67 | 1/3/07 | (51)Nemausa | HIP 48681 | M4 INTENSIFIED VIDEO | FAUCETT, MO |
| 66 | 12/22/06 | (547) Praxedis | TYC 4822-02645-1 | C8 INTENSIFIED VIDEO | TRAVIS, TX |
| 65 | 12/14/06 | (70) Panopaea | TYC 1231-01469-1 | C8 INTENSIFIED VIDEO | MADISONVILLE, TX |
| 64 | 11/26/06 | (422) Berolina | 2UCAC 42542715 | M8 VISUAL | TONKAWA, OK |
| 63 | 11/26/06 | (601) Nerthus | TYC 5764-01407-1 | M8 INTENSIFIED VIDEO | COLWICH, KS |
| 62 | 11/22/06 | (103) Hera | TYC 0040-00819-1 | C8 INTENSIFIED VIDEO | CENTERVILLE, TX |
| 61 | 11/21/06 | (302) Clarissa | TYC 1817-01424-1 | C8 INTENSIFIED VIDEO (VISUAL OFF SCREEN) | LAKE JACKSON, TX |
| 60 | 10/3/06 | (25) Phocaea | HIP 115725 | M10 INTENSIFIED VIDEO | WOODSTOWN, NJ |
| 59 | 7/12/06 | (444) Gyptis | TYC 5109-00140-1 | C8 INTENSIFIED VIDEO | ANGLETON, TX |
| 58 | 6/24/06 | (35) Leukothea | UCAC2 16455768 | C11 INTENSIFIED VIDEO | BOULOGNE, FL |
| 57 | 5/27/06 | (702) Alauda | UCAC2 13791670 | C8 INTENSIFIED VIDEO | LIVINGSTON, LA |
| 56 | 4/30/06 | (580) Selene | TYC 4973-01378-1 | C8 INTENSIFIED VIDEO | COLETOVILLE, TX |
| 55 | 3/12/06 | (602) Marianna | HIP 90871 | M 4 INTENSIFIED VIDEO | ABILENE, TX |
| 54 | 2/24/06 | (530) Turandot | HIP 40832 | M 4 INTENSIFIED VIDEO | CINCINNATI, OH |
| 53 | 2/10/06 | (134) Sophrosyne | TYC-2926-01789-1 | 36-INCH REFLECTOR INTENSIFIED VIDEO | HOUSTON, TX |
| 52 | 2/05/06 | (764) Gedania | UCAC2-35203988 | M 4 INTENSIFIED VIDEO | PENITAS, TX |
| 51 | 1/28/06 | (490) Veritas | TYC-0736-00356-1 | M 4 INTENSIFIED VIDEO | KEENANSVILLE, NC |
| 50 | 1/14/06 | (173) Ino | TYC-0145-00077-1 | M 4 INTENSIFIED VIDEO | LINN, TX |
| 49 | 1/5/06 | (466) Tisiphone | TYC-1371-00938-1 | C8 INTENSIFIED VIDEO | TELFERNER, TX |
| 48 | 12/11/05 | (28) Christine | UCAC2-37141382 | C8 INTENSIFIED VIDEO | HOCKLEY, TX |
| 47 | 12/03/05 | (52) Europa | TYC 4974-00584-1 | M 4 INTENSIFIED VIDEO | LAKE HAVASU CITY, AZ |
| 46 | 12/01/05 | (162) Laurentia | TYC 1799-00077-1 | C8 INTENSIFIED VIDEO | BUFFALO, TX |
| 45 | 11/15/05 | (345) Tercidina | TYC 05227-00241-1 | C8 INTENSIFIED VIDEO | WEIMAR, CA |
| 44 | 10/28/05 | (790) Pretoria | TYC 0216-01594-1 | M 4 INTENSIFIED VIDEO | CATOOSA, OK |
| 43 | 10/7/05 | (1082) Prirola | TYC 1311-2375-1 | C8 INTENSIFIED VIDEO | HOUSTON, TX |
| 42 | 8/13/05 | (893) Julia | HIP 7948 | 7x35mm VISUAL | PENSE, SASKATCHEWAN, CANADA |
| 41 | 7/11/05 | (103) Hera | TYC 1210-01821-1 | C8 INTENSIFIED VIDEO | SENTINEL, AZ |
| 40 | 6/13/05 | (103) Hera | TYC 6264-00003-1 | C8 INTENSIFIED VIDEO | GALVESTON ISLAND, TX |
| 39 | 5/17/05 | (54) Alexandra | TYC 7902-01828-1 | M 8 INTENSIFIED VIDEO | ACUFF, TX |
| 38 | 1/18/05 | (216) Kleopatra | UCAC 32014147 | C8 INTENSIFIED VIDEO | HOUSTON, TX |
| 37 | 10/29/04 | (8) Flora | TYC 1367-00024-1 | M 4 INTENSIFIED VIDEO | OROGRANDE, NM |
| 36 | 10/07/04 | (8) Flora | TYC 1351-00528-1 | C8 INTENSIFIED VIDEO | CLINTON, BC CANADA |
| 35 | 9/05/04 | (107) Camilla | TYC 5244-00017-1 | C8 INTENSIFIED VIDEO | FOUNTAIN HILLS, AZ |
| 34 | 8/25/04 | (11) Parthenope | TYC 6859-01200-1 | C8 INTENSIFIED VIDEO | ALVIN, TX |
| 33 | 7/18/04 | (41) Daphne | TYC 0531-02020-1 | C8 INTENSIFIED VIDEO | FRIENDSWOOD, TX |
| 32 | 7/3/04 | (64) Angelina | TYC 1215-01306-1 | C8 INTENSIFIED VIDEO | KRAMER JUNCTION, CA |
| 31 | 6/30/04 | (522) Helga | TYC 6310-01494-1 | C8 INTENSIFIED VIDEO | INYOKERN, CA |
| 30 | 12/31/03 | (208) Lacrimosa | TYC 1397-01764-1 | C8 INTENSIFIED VIDEO | SPLENDORA, TX |
| 29 | 12/14/03 | (231) Vindobona | TYC 2389-01522-1 | C8 INTENSIFIED VIDEO | MOUNTAINAIRE, AZ |
| 28 | 12/07/03 | (115) Thyra | TYC 5769-00278-1 | C8 INTENSIFIED VIDEO | ARIZONA CITY, AZ |
| 27 | 10/24/03 | (978) Aidamina | HIP 106841 | C8 INTENSIFIED VIDEO | TX,NM BORDER |
| 26 | 8/1/03 | TITANIA | TYC 5806-696-1 | 36INCH REFLECTOR VIDEO | BRAZOS BEND, TX |
| 25 | 7/29/03 | (654) Zelinda | TYC 6285-03426-1 | C8 INTENSIFIED VIDEO | STILLWELL, OK |
| 24 | 6/18/03 | (85) Io | TYC 0530-01006-1 | C8 INTENSIFIED VIDEO | HOUSTON, TX |
| 23 | 3/23/03 | (704) Interamnia | HIP 36189 | M12 VIDEO | KONA, HI |
| 22 | 1/15/03 | (95) Arethusa | TYC 0191-00774-1 | C8 VISUAL | MCCOOK, TX |
| 21 | 1/3/03 | (726) Joella | TYC 4848-02317-1 | C8 INTENSIFIED VIDEO | CASH, TX |
| 20 | 1/1/03 | (233) Asterope | TYC 0726-00419-1 | C8 INTENSIFIED VIDEO | SANTA FE, TX |
| 19 | 11/14/02 | (350) Ornamenta | TYC 0111-01007-1 | C8 INTENSIFIED VIDEO | ODEM, TX |
| 18 | 8/13/02 | (688) Melanie | TYC 5236-00201-1 | C8 INTENSIFIED VIDEO | HOUSTON, TX |
| 17 | 5/24/02 | (102) Miriam | TYC 6252-01873 | C8 INTENSIFIED VIDEO | RIO RICA, AZ |
| 16 | 4/20/02 | (139) Juewa | TYC 6148-00023 | C8 INTENSIFIED VIDEO | OAK RIDGE, CA |
| 15 | 3/27/02 | (654) Zelinda | TYC 0168-02620 | C8 INTENSIFIED VIDEO | VIOLA, KS |
| 14 | 1/14/02 | (516) Amherstia | SAO 060107 | C8 INTENSIFIED VIDEO | ATLANTIC BEACH, FL |
| 13 | 9/8/01 | TITANIA | ZC 3167 | C14 VISUAL | BARQUISIMETO, VENEZUELA |
| 12 | 10/31/01 | (48) Doris | TYC1315-01463-1 | 17-INCH REFLECTOR VISUAL | HOUSTON, TX |
| 11 | 12/4/97 | (105) Artemis | SAO 134036 | C8 VISUAL | PHOENIX, AZ |
| 10 | 12/17/96 | (704) Interamnia | BD+3 633 | C8 VISUAL | PHOENIX, AZ |
| 9 | 10/9/93 | (27) Euterpe | PPM 174714 | C8 VISUAL | DUMAS, TX |
| 8 | 1/3/91 | (4) Vesta | SAO 93228 | C8 VIDEO | LAPEER, MI |
| 7 | 4/11/85 | (129) Antigone | BD+20 2390 | C8 VISUAL | PARKER, CO |
| 6 | 5/29/83 | (2) Pallas | 1 Vulpeculae | C8 VISUAL | SPLENDORA, TX |
| 5 | 4/26/83 | (52) Europa | BD+21 1797 | C8 VISUAL | HOUSTON, TX |
| 4 | 11/15/82 | (375) Ursula | SAO55791 | C8 VISUAL | WINNIE, TX |
| 3 | 10/7/81 | (88) Thisbe | SAO 187124 | C8 VISUAL | CHEYENNE, WY |
| 2 | 12/11/79 | (9) Metis | SAO 80950 | 5R VISUAL | GEORGETOWN, GUYANA |
| 1 | 3/5/77 | (6) Hebe | Gamma Ceti | 5R VISUAL | VICTORIA, TX |
Some instruments I use include the 50mm mini, 80mm midi and 120mm maxi. Each is
chosen based on the limiting magnitude of the target star.
The 120mm maxi scope is an f/5 refractor mounted in an alt-az configuration
The 80mm midi is also an f/5 refractor mounted on a tripod. Note that all instruments are spray painted black.
Support equipment include the camcorder, battery, KIWI GPS unit, VCR timer and associated cables.
My method of observation changed in 2001 when I purchased a red sensitive 3rd generation image intensifier from Collins Electro Optics. This remarkable device is vastly superior to either visual or video observation alone. But for general occultation observation of stars down to +10, for example, intensification is really not needed. I use it because it improves the chances for faint star detection in the event that the target is between +11 and +12. In a star field crowded with dim stars, or in a case where the target is a close double, the intensifier makes a vast difference. Recall that visual observation has built in human reaction time as well as the inability to play the observation back to check its accuracy and show it to others.