Asteroids in Motion

Asteroid positions were documented photographically using a Canon EOS60Da on the Meade 12” ACF working at prime focus (f/10) at Makemie Woods. All exposures were unguided, and a uniform exposure of 30-seconds using ISO 1000 was used in sets of three (generally). None of the animated gif images were calibrated (using darks and biases, which were taken but just not used for the data reduction this time), nor were they stacked; the best of each triplet was chosen to use in the animated gif. The first night out pursuing this type of asteroid data collection (Jan 22, 2015) resulted in selecting certain asteroids for reasons based on their position and brightness. The objective was to image each asteroid twice during the night with enough time between exposures so that the asteroid’s motion would be detectable. Hence, asteroids too near the west in the early evening were skipped. Brighter targets are best for starting a process, so several asteroids with magnitudes brighter than 14th were selected. The start-time of the 30-s exposure is labeled in the image, as is the asteroid identifier.

Thirty-six asteroids were imaged over a 2-hour span starting at 6:55 pm EST on January 22, 2015. Unfortunately, right at the turning point in the run where enough time had elapsed to start securing the second images (9:00 pm), clouds started to encroach which degraded the image quality significantly. If fact, the first two targets were repeated as holes in the haze allowed a better view if only briefly, and only 16 second-photo targets were secured. The haze and clouds cause a dimming and a smearing effect where the faintest star images are missing and all stellar images are noticeably spread out. As the 17th target was re-imaged to document its motion, the clouds had become too thick to record any of the stars and asteroids.

The following two attempts were better served. Both sessions (nights of January 28-29 and January 30-31, 2015) remained clear so that both photos that are required to positively show motion for all of the targets could be taken. For each asteroid, I wanted to wait long enough so the motion is apparent, yet not so long as to have the asteroid leave the field of view since I want to show not only the new position, but the vacancy from the previous position all in one framed view. Since I aimed the telescope at the asteroid without necessarily centering it, the overlapped region of the two photos are always smaller than the full frame (the full frame extends 17 x 25 arc minutes, so almost all of these have been cropped to show only a part of the regions-in-common between the pair of photos and will have smaller coverage). The amount of cropping varied, but is typically around 15% leaving a span of about 20 arc-minutes along the longest dimension (R.A.). Note that some slight field rotation also needed to be corrected, but this never exceeded 1 deg, so North is essentially up and East to the left in all of the images.

Some images were taken when the target asteroid was closely aligned with the Moon, and glare streaks are evident (see, for example, (66) Maja or (540) Rosamunde) in one or more of the pair. In cases where the asteroid is very weakly recorded, identifiers (arrows or surrounding ovals) are included.

The Near Earth Asteroid 2004 BL86 is a special case since its close approach to Earth on Janary 26 was only about 3.1 lunar distances. Its proximity produced a large angular motion on January 30-31, 2015, when Mark took these images. A series of 15-second exposures were used to create the frame animation with a 121-second and 206-second exposure tacked onto the end of the sequence, the track produced by the asteroid in the 206-second exposure shown here. Click on it for the animated gif (9MB).


Asteroid2004BL86moving_480x300.gif, 9MB

Asteroid (4179)Toutatis made a close approach to Earth on 12/12/2012 at a distance of 18 lunar distances and, similar to Asteroid 2004 BL86, was easily picked out among the background stars back in late 2012 by monitoring its motion over the course of mere minutes. Here is a 2 minute exposure taken 12/15/2012 at prime focus on the 12" f/10 SCT at Makemie Woods using a Canon 60Da at ISO 1000.


Asteroid (4179)Toutatis

Both of these asteroids passed close to Earth, making their apparent motion fast enough to be monitored visually by a patient observer (measured in arc seconds per minute.) Most of the other asteroids studied here are typically 20 to 50 times more distant; their slow orbital speeds of their larger orbits and greater distances combine to create angular rates hundreds of times slower. And then, some of the asteroids were caught close to entering or exiting retrograde motion making them have especially slow angular rates as is the case for (321) Florentina which hardly moved over the 2 hours between exposures taken about a day after it resumed its prograde motion.

The following animated gifs are blinking pairs that are labelled with the asteroid identifier and the date/times of the start of the 30-second exposures being blinked. The typical file size is about 300KB and each is opened in a separate tab. A repository of scaled, annotated negatives of the original images used to create the animated gifs is also available. Each is approximately 2250x900 pixels, 8MB in size.

Asteroid (3)Juno
03:18:24 - 05:15:18 UTC
01/31/2015
Asteroids (23)Thalia,(476)Hedwig
01:18:07 - 03:38:37 UTC
01/29/2015
Asteroid (25)Phocaea
01:57:28 - 04:18:42 UTC
01/29/2015
Asteroid (28)Bellona
00:31:01 - 03:17:55 UTC
01/23/2015
Asteroid (37)Fides
23:49:46 - 02:29:23 UTC
01/22-23/2015
Asteroid (38)Leda
04:48:18 - 06:35:21 UTC
01/31/2015
Asteroid (42)Isis
03:50:39 - 05:44:05 UTC
01/31/2015
Asteroid (47)Aglaja
00:52:05 - 03:08:02 UTC
01/29/2015
Asteroid (52)Europa
00:37:17 - 03:21:12 UTC
01/23/2015
Asteroid (55)Pandora
00:19:47 - 03:04:18 UTC
01/23/2015
Asteroid (58)Concordia
04:41:22 - 06:28:40 UTC
01/31/2015
Asteroid (66)Maja
01:13:07 - 03:29:10 UTC
01/29/2015
Asteroid (71)Niobe
04:08:40 - 06:01:25 UTC
01/31/2015
Asteroid (78)Diana
00:30:06 - 03:14:38 UTC
01/23/2015
Asteroid (84)Klio
23:58:11 - 02:15:31 UTC
01/22-23/2015
Asteroid (86)Semele
03:59:54 - 05:52:06 UTC
01/31/2015
Asteroid (88)Thisbe
00:14:00 - 02:59:01 UTC
01/23/2015
Asteroids (89)Julia,(335)Roberta
04:14:45 - 06:05:24 UTC
01/31/2015
Asteroid (93)Minerva
00:55:23 - 03:09:41 UTC
01/29/2015
Asteroid (127)Johanna
00:26:09 - 02:38:59 UTC
01/29/2015
Asteroid (128)Nemesis
03:51:35 - 05:46:03 UTC
01/31/2015
Asteroid (136)Austria
02:27:46 - 04:43:39 UTC
01/29/2015
Asteroid (137)Meliboea
02:05:52 - 04:27:39 UTC
01/29/2015
Asteroid (148)Gallia
01:58:53 - 04:19:43 UTC
01/29/2015
Asteroid (152)Atala
00:23:06 - 03:08:46 UTC
01/23/2015
Asteroid (160)Una
01:34:09 - 03:55:44 UTC
01/29/2015
Asteroid (164)Eva
03:30:55 - 06:27:09 UTC
01/31/2015
Asteroid (169)Zelia
01:27:56 - 03:49:47 UTC
01/29/2015
Asteroid (170)Maria
00:01:05 - 02:19:49 UTC
01/23/2015
Asteroid (173)Ino
02:21:15 - 04:37:53 UTC
01/29/2015
Asteroid (195)Eurykleia
03:48:17 - 05:40:51 UTC
01/31/2015
Asteroid (196)Philomela
01:36:25 - 03:57:12 UTC
01/29/2015
Asteroid (210)Isabella
01:32:23 - 03:52:22 UTC
01/29/2015
Asteroids (219)Thusnelda,(732)Tjilaki,(694)Ekard
02:09:29 - 04:30:15 UTC
01/29/2015
Asteroid (222)Lucia
04:34:10 - 06:23:06 UTC
01/31/2015
Asteroid (245)Vera
00:33:27 - 02:45:36 UTC
01/29/2015
Asteroid (250)Bettina
00:16:53 - 03:01:32 UTC
01/23/2015
Asteroid (284)Amalia
03:20:46 - 05:18:29 UTC
01/31/2015
Asteroid (321)Florentina
01:40:03 - 03:59:54 UTC
01/29/2015
Asteroid (326)Tamara
03:35:04 - 05:30:08 UTC
01/31/2015
Asteroid (333)Badenia
00:30:03 - 02:43:15 UTC
01/29/2015
Asteroid (337)Devosa
02:55:01 - 04:59:32 UTC
01/31/2015
Asteroid (357)Ninina
01:49:47 - 04:16:27 UTC
01/29/2015
Asteroid (378)Holmia
04:18:53 - 06:09:15 UTC
01/31/2015
Asteroid (389)Industria
23:54:41 - 02:32:30 UTC
01/22-23/2015
Asteroid (407)Arachne
00:04:45 - 02:21:31 UTC
01/23/2015
Asteroid (416)Vaticana
00:35:32 - 02:48:13 UTC
01/29/2015
Asteroid (418)Alemannia
03:22:34 - 05:19:57 UTC
01/31/2015
Asteroid (419)Aurelia
01:44:19 - 04:03:08 UTC
01/29/2015
Asteroid (425)Cornelia
03:56:51 - 05:50:11 UTC
01/31/2015
Asteroid (435)Ella
04:12:09 - 06:02:57 UTC
01/31/2015
Asteroid (436)Patricia
03:37:17 - 05:33:16 UTC
01/31/2015
Asteroid (445)Edna
03:16:05 - 05:13:21 UTC
01/31/2015
Asteroid (449)Hamburga
04:01:47 - 05:54:07 UTC
01/31/2015
Asteroid (477)Italia
00:49:54 - 03:04:45 UTC
01/29/2015
Asteroid (480)Hansa
00:11:59 - 02:54:59 UTC
01/23/2015
Asteroid (481)Emita
01:14:37 - 03:31:10 UTC
01/29/2015
Asteroid (482)Petrina
02:04:17 - 04:24:17 UTC
01/29/2015
Asteroid (507)Laodica
04:17:11 - 06:07:50 UTC
01/31/2015
Asteroid (510)Mabella
01:47:37 - 04:08:59 UTC
01/29/2015
Asteroid (512)Taurinensis
03:05:15 - 05:04:32 UTC
01/31/2015
Asteroid (522)Helga
04:06:24 - 05:58:40 UTC
01/31/2015
Asteroid (524)Fidelio
03:55:06 - 05:48:05 UTC
01/31/2015
Asteroid (528)Rezia
01:19:32 - 03:42:47 UTC
01/29/2015
Asteroid (537)Pauly
04:26:18 - 06:17:03 UTC
01/31/2015
Asteroid (539)Pamina
03:25:16 - 05:22:30 UTC
01/31/2015
Asteroid (540)Rosamunde
01:46:28 - 04:06:14 UTC
01/29/2015
Asteroid (544)Jetta
04:44:47 - 06:33:26 UTC
01/31/2015
Asteroid (566)Stereoskopia
02:58:44 - 05:01:59 UTC
01/31/2015
Asteroid (569)Misa
01:42:14 - 04:02:05 UTC
01/29/2015
Asteroid (576)Emanuela
00:56:27 - 03:12:08 UTC
01/29/2015
Asteroid (583)Klotilde
04:24:34 - 06:13:52 UTC
01/31/2015
Asteroid (601)Nerthus
04:22:45 - 06:12:16 UTC
01/31/2015
Asteroid (603)Timandra
00:58:32 - 03:15:14 UTC
01/29/2015
Asteroid (615)Roswitha
04:38:39 - 0626:34 UTC
01/31/2015
Asteroid (623)Chimaera
03:28:19 - 05:24:44 UTC
01/31/2015
Asteroid (632)Pyrrha
04:32:38 - 06:20:29 UTC
01/31/2015
Asteroid (636)Erika
00:27:49 - 02:41:13 UTC
01/29/2015
Asteroid (676)Melitta
02:26:42 - 04:42:45 UTC
01/29/2015
Asteroid (677)Aaltje
00:38:13 - 02:51:24 UTC
01/29/2015
Asteroid (691)Lehigh
03:45:26 - 05:39:17 UTC
01/31/2015
Asteroid (695)Bella
00:26:44 - 03:12:18 UTC
01/23/2015
Asteroid (702)Alauda
01:05:49 - 03:20:45 UTC
01/29/2015
Asteroid (706)Hirando
01:08:01 - 03:24:03 UTC
01/29/2015
Asteroid (708)Raphaela
00:42:05 - 02:52:56 UTC
01/29/2015
Asteroid (714)Ulula
02:18:48 - 04:35:07 UTC
01/29/2015
Asteroid (715)Transvaalia
00:39:18 - 03:01:55 UTC
01/29/2015
Asteroid (726)Joella
02:23:37 - 04:40:08 UTC
01/29/2015
Asteroid (727)Nipponia
04:37:01 - 06:24:08 UTC
01/31/2015
Asteroid (773)Irmintraud
00:07:28 - 02:25:33 UTC
01/23/2015
Asteroid (786)Bredichina
03:43:11 - 05:37:50 UTC
01/31/2015
Asteroid (820)Adriana
04:29:18 - 06:19:02 UTC
01/31/2015
Asteroid (823)Sisigambis
03:13:57 - 05:1117 UTC
01/31/2015
Asteroid (834)Burnhamia
03:10:19 - 05:09:09 UTC
01/31/2015
Asteroid (847)Agnia
04:43:21 - 06:3041 UTC
01/31/2015
Asteroid (862)Franzia
00:40:43 - 03:23:34 UTC
01/23/2015
Asteroid (892)Seeligeria
02:01:06 - 04:2240 UTC
01/29/2015
Asteroid (902)Probitas
01:22:19 - 03:44:58 UTC
01/29/2015
Asteroid (916)America
04:04:34 - 05:56:06 UTC
01/31/2015
Asteroid (994)Otthild
03:39:36 - 05:35:29 UTC
01/31/2015
Asteroid (996)Hilaritas
03:07:38 - 05:0817 UTC
01/31/2015


Last modified 2/6/2015