12923 Zephyr (1999 GK4)

NEO PHA MOID ⇩ IMP ⇩ COV ★ EPH ⇩ OBS
Orbital Elements
Epoch (TDB)2025-11-21 (JD 2461000.5)
Eccentricity (e)0.4927419454 ± 6.38e-09
Semi-major axis (a)1.9622252115 AU ± 6.65e-10
Inclination (i)5.30954016° ± 9.22e-07
Long. of Asc. Node (Ω)168.07921894° ± 1.08e-05
Arg. of Perihelion (ω)147.21088394° ± 1.08e-05
Mean Anomaly (M)194.87677812° ± 9.76e-07
Mean Motion (n)0.3585824243°/day ± 1.82e-10
Perihelion dist (q)0.99535454 AU ± 1.25e-08
Aphelion dist (Q)2.92909588 AU ± 1.25e-08
Orbital Period2.74867427 yr ± 1.40e-09
Physical Parameters
H (abs. magnitude)15.80
G (slope)0.15
Orbit Solution
SourceIAA
Solution Date2026-05-31
RMS Residual0.251″
Uncertainty0
Orbit TypeApollo
MOID0.019399 AU
Observations Used2585
Oppositions45
Arc Total1955-2026
First Observation Used1955-04-21
Last Observation Used2026-01-11
Observations (2948)
Date Type RA Dec Mag Band Observatory
1955-04-21 06:09:00 12 37 38.18 +02 03 46.3 675
1955-04-21 06:58:59 12 37 35.24 +02 04 13.0 675
1988-02-23 15:54:40 14 03 38.79 -09 39 35.2 413
1988-02-23 17:54:40 14 03 40.70 -09 39 28.4 413
1996-03-19 11:33:48 C 11 25 50.79 +04 37 15.4 t 566
1996-03-19 12:05:18 C 11 25 49.10 +04 37 28.6 t 566
1996-03-19 12:35:22 C 11 25 47.49 +04 37 41.5 t 566
1996-04-20 05:48:59 10 53 38.62 +08 57 34.8 261
1996-04-20 06:33:59 10 53 37.59 +08 57 43.7 261
1999-02-17 03:04:16 C 14 10 43.25 -10 27 52.1 z 910
1999-02-17 03:38:49 C 14 10 44.26 -10 27 51.8 z 910
1999-02-17 04:12:01 C 14 10 45.29 -10 27 52.7 z 910
1999-03-25 09:02:23 C 14 19 41.86 -08 16 17.8 c 699
1999-03-25 09:31:44 C 14 19 41.35 -08 16 07.2 c 699
1999-03-25 10:01:07 C 14 19 40.82 -08 15 55.8 c 699
1999-04-11 08:50:20 C 14 07 28.01 -05 11 29.8 c 699
1999-04-11 09:19:41 C 14 07 26.60 -05 11 13.4 c 699
1999-04-11 09:49:02 C 14 07 25.25 -05 10 57.5 c 699
1999-04-12 02:32:09 C 14 06 40.93 -05 01 40.3 c 758
1999-04-12 02:43:33 C 14 06 40.38 -05 01 33.5 c 758
1999-04-12 02:53:53 C 14 06 39.91 -05 01 27.5 c 758
1999-04-12 05:08:59 C 14 06 33.50 -05 00 11.0 z 732
1999-04-12 05:15:57 C 14 06 33.15 -05 00 06.9 z 732
1999-04-12 05:22:56 C 14 06 32.85 -05 00 02.9 z 732
1999-04-12 05:27:55 C 14 06 31.98 -04 59 53.2 z 859
1999-04-12 05:33:23 C 14 06 31.72 -04 59 50.4 z 859
1999-04-12 05:40:18 C 14 06 31.38 -04 59 46.4 z 859
1999-04-12 07:24:55 C 14 06 27.05 -04 58 58.0 18.0 a 704
1999-04-12 07:49:49 C 14 06 25.80 -04 58 44.4 a 704
1999-04-12 08:10:05 C 14 06 24.91 -04 58 33.6 z 719
1999-04-12 08:14:27 C 14 06 24.64 -04 58 29.9 a 704
1999-04-12 08:27:05 C 14 06 24.04 -04 58 22.0 z 719
1999-04-12 08:39:08 C 14 06 23.44 -04 58 16.8 18.6 a 704
1999-04-12 09:00:20 C 14 06 22.42 -04 58 04.1 z 719
1999-04-12 09:03:54 C 14 06 22.27 -04 58 03.3 18.4 a 704
1999-04-12 09:08:09 C 14 06 22.09 -04 57 59.4 z 719
1999-04-12 10:28:55 C 14 06 18.15 -04 57 14.4 z 719
1999-04-12 14:24:19 C 14 06 07.66 -04 54 50.3 422
1999-04-12 14:25:59 C 14 06 07.57 -04 54 49.7 422
1999-04-12 14:30:16 C 14 06 07.38 -04 54 47.1 422
1999-04-12 14:31:30 C 14 06 07.33 -04 54 46.5 422
1999-04-12 23:13:45 C 14 05 43.04 -04 50 05.9 557
1999-04-12 23:16:36 C 14 05 42.95 -04 50 04.4 557
1999-04-12 23:46:20 C 14 05 41.45 -04 49 47.4 b 118
1999-04-12 23:49:04 C 14 05 41.32 -04 49 45.9 b 118
1999-04-12 23:51:23 C 14 05 41.20 -04 49 44.8 b 118
1999-04-13 02:41:39 C 14 05 33.81 -04 48 04.1 c 758
1999-04-13 02:49:49 C 14 05 33.42 -04 47 59.6 c 758
1999-04-13 02:57:06 C 14 05 33.06 -04 47 55.1 c 758
1999-04-13 12:18:04 C 14 05 06.27 -04 42 26.1 z 428