C/2017 U4 (PANSTARRS)

메타데이터

항목
Designation C/2017 U4 (PANSTARRS)
Type C
Perihelion (tp_cal, UTC) 2018-09-25T16:38:00.893760Z
Orbit solution date (soln_date, UTC) 2023-02-13T23:12:42Z
Obs used 85
NEO -
M1 7.100
K1 10.750
PC -
Osculating 궤도요소
항목
Epoch (epoch_cal, TDB) 2018-01-03.0000000
e 1.00304382
q (au) 7.724158
a (au) -2537.649728
i (deg) 158.225721
Ω (om, deg) 245.952559
ω (w, deg) 159.177100
M (ma, deg) -0.002049

밝기

C/2017 U4 (PANSTARRS) · Magnitude (Full range)

산란 + 전체 선형

$$ M_a = (2.306 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

모델 상수

항목
H0 2.306
n 6.000
gf 0.992
gb -1.000
k 1.000
δ90 9.972
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

천체력

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-05-12 00:00 00:14:25.07 -20:47:30.0 HIP 1072 18.75
2026-05-12 12:00 00:14:28.07 -20:47:45.0 HIP 1072 19.47
2026-05-13 00:00 00:14:31.04 -20:48:00.4 HIP 1072 20.19
2026-05-13 12:00 00:14:33.96 -20:48:16.2 HIP 1072 20.91
2026-05-14 00:00 00:14:36.85 -20:48:32.5 HIP 1072 21.63
2026-05-14 12:00 00:14:39.69 -20:48:49.2 HIP 1072 22.34
2026-05-15 00:00 00:14:42.50 -20:49:06.4 HIP 1072 23.05
2026-05-15 12:00 00:14:45.27 -20:49:24.0 HIP 1147 23.10
2026-05-16 00:00 00:14:47.99 -20:49:42.1 HIP 1147 22.97
2026-05-16 12:00 00:14:50.67 -20:50:00.6 HIP 1147 22.86
2026-05-17 00:00 00:14:53.32 -20:50:19.6 HIP 1147 22.76
2026-05-17 12:00 00:14:55.92 -20:50:39.1 HIP 1147 22.66
2026-05-18 00:00 00:14:58.48 -20:50:58.9 HIP 1147 22.58
2026-05-18 12:00 00:15:00.99 -20:51:19.3 HIP 1147 22.50
2026-05-19 00:00 00:15:03.47 -20:51:40.1 HIP 1147 22.44
2026-05-19 12:00 00:15:05.90 -20:52:01.3 HIP 1147 22.38
2026-05-20 00:00 00:15:08.28 -20:52:23.0 HIP 1147 22.34
2026-05-20 12:00 00:15:10.63 -20:52:45.1 HIP 1147 22.30
2026-05-21 00:00 00:15:12.93 -20:53:07.7 HIP 1147 22.26
2026-05-21 12:00 00:15:15.18 -20:53:30.7 HIP 1147 22.24
2026-05-22 00:00 00:15:17.40 -20:53:54.2 HIP 1147 22.22
2026-05-22 12:00 00:15:19.56 -20:54:18.1 HIP 1147 22.21
2026-05-23 00:00 00:15:21.68 -20:54:42.5 HIP 1147 22.20
2026-05-23 12:00 00:15:23.76 -20:55:07.3 HIP 1147 22.20
2026-05-24 00:00 00:15:25.79 -20:55:32.6 HIP 1147 22.21
2026-05-24 12:00 00:15:27.78 -20:55:58.3 HIP 1147 22.22
2026-05-25 00:00 00:15:29.72 -20:56:24.5 HIP 1147 22.24
2026-05-25 12:00 00:15:31.61 -20:56:51.0 HIP 1147 22.26
2026-05-26 00:00 00:15:33.46 -20:57:18.1 HIP 1147 22.29
2026-05-26 12:00 00:15:35.27 -20:57:45.5 HIP 1147 22.32
2026-05-27 00:00 00:15:37.02 -20:58:13.5 HIP 1147 22.35
2026-05-27 12:00 00:15:38.73 -20:58:41.8 HIP 1147 22.39
2026-05-28 00:00 00:15:40.39 -20:59:10.6 HIP 1147 22.43
2026-05-28 12:00 00:15:42.00 -20:59:39.8 HIP 1147 22.48
2026-05-29 00:00 00:15:43.57 -21:00:09.5 HIP 1147 22.53
2026-05-29 12:00 00:15:45.09 -21:00:39.6 HIP 1147 22.58
2026-05-30 00:00 00:15:46.56 -21:01:10.1 HIP 1147 22.63
2026-05-30 12:00 00:15:47.98 -21:01:41.1 HIP 1147 22.69
2026-05-31 00:00 00:15:49.35 -21:02:12.5 HIP 1147 22.75
2026-05-31 12:00 00:15:50.68 -21:02:44.4 HIP 1147 22.82
2026-06-01 00:00 00:15:51.96 -21:03:16.6 HIP 1147 22.89
2026-06-01 12:00 00:15:53.18 -21:03:49.4 HIP 1147 22.96
2026-06-02 00:00 00:15:54.36 -21:04:22.5 HIP 1147 23.03