C/2018 X2 (Fitzsimmons)

메타데이터

항목 값
Designation C/2018 X2 (Fitzsimmons)
Type C
Perihelion (tp_cal, UTC) 2019-07-08T12:50:12.180480Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:33:48Z
Obs used 390
NEO -
M1 10.600
K1 12.750
PC 0.030
Discovery observation (MPC, UTC) 2018-12-08T11:10:09.696000Z
Discovery magnitude (MPC) 19.10 c
Discovery observatory (MPC) T05 · ATLAS-HKO, Haleakala
Osculating 궤도요소
항목 값
Epoch (epoch_cal, TDB) 2019-02-10.0000000
e 0.98628022
q (au) 2.125879
a (au) 154.949983
i (deg) 23.068234
Ω (om, deg) 340.833210
ω (w, deg) 162.047045
M (ma, deg) 359.924099

밝기

C/2018 X2 (Fitzsimmons) · Magnitude (Full range)

산란 + 전체 선형

$$ M_a = (10.225 + 5.892\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

모델 상수

항목 값
H0 10.225
n 5.892
gf 0.996
gb -0.500
k 0.800
δ90 2.692
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)
2026-09-20 00:00 19:10:31.93 -41:54:01.2 HIP 94157 6.40
2026-09-20 12:00 19:10:30.25 -41:53:30.5 HIP 94157 6.07
2026-09-21 00:00 19:10:28.65 -41:52:59.6 HIP 94157 5.79
2026-09-21 12:00 19:10:27.12 -41:52:28.6 HIP 94157 5.59
2026-09-22 00:00 19:10:25.67 -41:51:57.5 HIP 94157 5.45
2026-09-22 12:00 19:10:24.28 -41:51:26.2 HIP 94157 5.38
2026-09-23 00:00 19:10:22.96 -41:50:54.8 HIP 94157 5.39
2026-09-23 12:00 19:10:21.72 -41:50:23.3 HIP 94157 5.47
2026-09-24 00:00 19:10:20.55 -41:49:51.6 HIP 94157 5.63
2026-09-24 12:00 19:10:19.45 -41:49:19.9 HIP 94157 5.84
2026-09-25 00:00 19:10:18.41 -41:48:48.0 HIP 94157 6.11
2026-09-25 12:00 19:10:17.46 -41:48:15.9 HIP 94157 6.43
2026-09-26 00:00 19:10:16.57 -41:47:43.8 HIP 94157 6.79
2026-09-26 12:00 19:10:15.75 -41:47:11.5 HIP 94157 7.18
2026-09-27 00:00 19:10:15.01 -41:46:39.1 HIP 94157 7.60
2026-09-27 12:00 19:10:14.33 -41:46:06.6 HIP 94157 8.05
2026-09-28 00:00 19:10:13.73 -41:45:34.0 HIP 94157 8.51
2026-09-28 12:00 19:10:13.20 -41:45:01.3 HIP 94157 8.99
2026-09-29 00:00 19:10:12.74 -41:44:28.5 HIP 94157 9.48
2026-09-29 12:00 19:10:12.35 -41:43:55.6 HIP 94157 9.99
2026-09-30 00:00 19:10:12.03 -41:43:22.6 HIP 94157 10.50
2026-09-30 12:00 19:10:11.79 -41:42:49.5 HIP 94157 11.03
2026-10-01 00:00 19:10:11.61 -41:42:16.3 HIP 94157 11.56
2026-10-01 12:00 19:10:11.51 -41:41:42.9 HIP 94157 12.10
2026-10-02 00:00 19:10:11.48 -41:41:09.5 HIP 94157 12.64
2026-10-02 12:00 19:10:11.52 -41:40:36.1 HIP 94157 13.19
2026-10-03 00:00 19:10:11.63 -41:40:02.5 HIP 94157 13.74
2026-10-03 12:00 19:10:11.81 -41:39:28.8 HIP 94157 14.30
2026-10-04 00:00 19:10:12.06 -41:38:55.1 HIP 94157 14.86
2026-10-04 12:00 19:10:12.39 -41:38:21.2 HIP 94157 15.43
2026-10-05 00:00 19:10:12.78 -41:37:47.3 HIP 94157 16.00
2026-10-05 12:00 19:10:13.25 -41:37:13.3 HIP 94157 16.57
2026-10-06 00:00 19:10:13.79 -41:36:39.3 HIP 94157 17.15
2026-10-06 12:00 19:10:14.40 -41:36:05.1 HIP 94157 17.73
2026-10-07 00:00 19:10:15.08 -41:35:30.9 HIP 94157 18.31
2026-10-07 12:00 19:10:15.83 -41:34:56.7 HIP 94157 18.90
2026-10-08 00:00 19:10:16.65 -41:34:22.3 HIP 94157 19.49
2026-10-08 12:00 19:10:17.54 -41:33:47.9 HIP 94157 20.08
2026-10-09 00:00 19:10:18.51 -41:33:13.4 HIP 94116 19.91
2026-10-09 12:00 19:10:19.54 -41:32:38.9 HIP 94116 19.48
2026-10-10 00:00 19:10:20.65 -41:32:04.3 HIP 94116 19.06
2026-10-10 12:00 19:10:21.83 -41:31:29.7 HIP 94116 18.66
2026-10-11 00:00 19:10:23.07 -41:30:55.0 HIP 94116 18.28