C/2012 S1 (ISON)

메타데이터

항목
Designation C/2012 S1 (ISON)
Type C
Perihelion (tp_cal, UTC) 2013-11-28T18:20:55.495680Z
Orbit solution date (soln_date, UTC) 2025-11-21T13:42:48Z
Obs used 6684
NEO -
M1 10.400
K1 4.500
PC -
Osculating 궤도요소
항목
Epoch (epoch_cal, TDB) 2013-05-01.0000000
e 1.00000509
q (au) 0.012467
a (au) -2446.893404
i (deg) 62.162896
Ω (om, deg) 295.686541
ω (w, deg) 345.541197
M (ma, deg) -0.001724

밝기

C/2012 S1 (ISON) · Magnitude (Full range)

C/2012 S1 (ISON) · Magnitude (Highlight period)

산란 + 전체 선형

$$ M_a = (11.695 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

모델 상수

항목
H0 11.695
n 2.000
gf 1.000
gb -0.791
k 0.951
δ90 10.000
파라미터 기호 범위 설명
태양·지구거리 1 AU에서의 절대등급 H0 -5 to 20 혜성의 고유 밝기
광도 기울기 파라미터 n 2 to 6 태양거리 변화에 따른 밝기 변화율
전방 산란 비대칭 계수 gf 0.8 to 1 전방 산란의 강도
후방 산란 비대칭 계수 gb -1 to -0.5 후방 산란의 강도
분할 계수 k 0.8 to 1 전·후방 산란 기여도 비율
먼지/가스 밝기 비 δ90 1 to 10 코마에서 먼지 산란 대비 가스 방출의 상대 기여

참고: EPSC-DPS2025-160

잔차 (구간 선형)

$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$

시작일 (UTC) 끝 (UTC) a b
2011-09-30 2013-11-13 +0.7784 -0.530
2013-11-13 2013-11-28 +7.8926 -0.124

log10 r = log10(태양거리/AU), Δ = 지구거리(AU)

천체력

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-05-12 00:00 07:18:19.10 +37:04:51.9 HIP 35225 20.60
2026-05-12 12:00 07:18:21.54 +37:04:36.2 HIP 35225 21.15
2026-05-13 00:00 07:18:24.02 +37:04:20.4 HIP 35225 21.71
2026-05-13 12:00 07:18:26.53 +37:04:04.7 HIP 35225 22.28
2026-05-14 00:00 07:18:29.07 +37:03:49.1 HIP 35225 22.85
2026-05-14 12:00 07:18:31.64 +37:03:33.4 HIP 35225 23.42
2026-05-15 00:00 07:18:34.23 +37:03:17.8 HIP 35225 24.00
2026-05-15 12:00 07:18:36.86 +37:03:02.2 HIP 35477 24.28
2026-05-16 00:00 07:18:39.52 +37:02:46.6 HIP 35477 23.84
2026-05-16 12:00 07:18:42.20 +37:02:31.0 HIP 35477 23.41
2026-05-17 00:00 07:18:44.92 +37:02:15.5 HIP 35477 22.99
2026-05-17 12:00 07:18:47.66 +37:02:00.0 HIP 35477 22.57
2026-05-18 00:00 07:18:50.43 +37:01:44.5 HIP 35477 22.15
2026-05-18 12:00 07:18:53.23 +37:01:29.1 HIP 35477 21.75
2026-05-19 00:00 07:18:56.05 +37:01:13.7 HIP 35477 21.36
2026-05-19 12:00 07:18:58.91 +37:00:58.3 HIP 35477 20.97
2026-05-20 00:00 07:19:01.79 +37:00:43.0 HIP 35477 20.60
2026-05-20 12:00 07:19:04.70 +37:00:27.7 HIP 35477 20.24
2026-05-21 00:00 07:19:07.63 +37:00:12.4 HIP 35477 19.89
2026-05-21 12:00 07:19:10.60 +36:59:57.2 HIP 35477 19.56
2026-05-22 00:00 07:19:13.58 +36:59:42.0 HIP 35477 19.25
2026-05-22 12:00 07:19:16.60 +36:59:26.8 HIP 35477 18.95
2026-05-23 00:00 07:19:19.64 +36:59:11.7 HIP 35477 18.67
2026-05-23 12:00 07:19:22.70 +36:58:56.7 HIP 35477 18.41
2026-05-24 00:00 07:19:25.79 +36:58:41.6 HIP 35477 18.17
2026-05-24 12:00 07:19:28.91 +36:58:26.6 HIP 35477 17.95
2026-05-25 00:00 07:19:32.05 +36:58:11.7 HIP 35477 17.76
2026-05-25 12:00 07:19:35.22 +36:57:56.8 HIP 35477 17.60
2026-05-26 00:00 07:19:38.40 +36:57:41.9 HIP 35477 17.46
2026-05-26 12:00 07:19:41.62 +36:57:27.1 HIP 35477 17.34
2026-05-27 00:00 07:19:44.86 +36:57:12.3 HIP 35477 17.26
2026-05-27 12:00 07:19:48.12 +36:56:57.6 HIP 35477 17.21
2026-05-28 00:00 07:19:51.40 +36:56:42.9 HIP 35477 17.18
2026-05-28 12:00 07:19:54.71 +36:56:28.3 HIP 35477 17.19
2026-05-29 00:00 07:19:58.04 +36:56:13.7 HIP 35477 17.23
2026-05-29 12:00 07:20:01.39 +36:55:59.2 HIP 35477 17.30
2026-05-30 00:00 07:20:04.77 +36:55:44.7 HIP 35477 17.41
2026-05-30 12:00 07:20:08.16 +36:55:30.3 HIP 35477 17.54
2026-05-31 00:00 07:20:11.58 +36:55:15.9 HIP 35477 17.71
2026-05-31 12:00 07:20:15.02 +36:55:01.6 HIP 35477 17.91
2026-06-01 00:00 07:20:18.49 +36:54:47.3 HIP 35477 18.13
2026-06-01 12:00 07:20:21.97 +36:54:33.1 HIP 35477 18.39
2026-06-02 00:00 07:20:25.47 +36:54:18.9 HIP 35477 18.68