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C/2018 A3 (ATLAS)

메타데이터

항목
Designation C/2018 A3 (ATLAS)
Type C
Perihelion (tp_cal, UTC) 2019-01-12T20:43:26.261760Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:33:39Z
Obs used 1589
NEO -
M1 9.400
K1 9.000
PC 0.030
Osculating 궤도요소
항목
Epoch (epoch_cal, TDB) 2018-12-07.0000000
e 0.99339311
q (au) 3.276715
a (au) 495.953962
i (deg) 139.561983
Ω (om, deg) 194.279275
ω (w, deg) 86.426299
M (ma, deg) 359.996710

밝기

C/2018 A3 (ATLAS) · Magnitude (Full range)

산란 + 전체 선형

$$ M_a = (10.483 + 3.261\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

모델 상수

항목
H0 10.483
n 3.261
gf 0.999
gb -0.500
k 0.800
δ90 3.469
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
2018-01-10 2019-01-12 +0.8638 -0.847
2019-01-12 2019-10-05 -2.0619 +1.339
2019-10-05 2020-10-24 +4.9810 -2.845

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

천체력

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-02-03 00:00 23:35:17.53 -26:12:33.9 HIP 116269 24.88
2026-02-03 12:00 23:35:22.14 -26:11:54.2 HIP 116269 26.05
2026-02-04 00:00 23:35:26.78 -26:11:14.6 HIP 116269 27.23
2026-02-04 12:00 23:35:31.45 -26:10:35.1 HIP 116269 28.43
2026-02-05 00:00 23:35:36.15 -26:09:55.6 HIP 116547 27.75
2026-02-05 12:00 23:35:40.89 -26:09:16.3 HIP 116547 26.52
2026-02-06 00:00 23:35:45.65 -26:08:37.0 HIP 116547 25.28
2026-02-06 12:00 23:35:50.45 -26:07:57.9 HIP 116547 24.04
2026-02-07 00:00 23:35:55.27 -26:07:18.9 HIP 116547 22.81
2026-02-07 12:00 23:36:00.12 -26:06:40.0 HIP 116547 21.57
2026-02-08 00:00 23:36:05.01 -26:06:01.2 HIP 116547 20.33
2026-02-08 12:00 23:36:09.92 -26:05:22.5 HIP 116547 19.09
2026-02-09 00:00 23:36:14.86 -26:04:43.9 HIP 116547 17.85
2026-02-09 12:00 23:36:19.82 -26:04:05.4 HIP 116547 16.62
2026-02-10 00:00 23:36:24.82 -26:03:27.1 HIP 116547 15.39
2026-02-10 12:00 23:36:29.84 -26:02:48.9 HIP 116547 14.18
2026-02-11 00:00 23:36:34.89 -26:02:10.8 HIP 116547 12.97
2026-02-11 12:00 23:36:39.96 -26:01:32.9 HIP 116547 11.79
2026-02-12 00:00 23:36:45.06 -26:00:55.1 HIP 116547 10.63
2026-02-12 12:00 23:36:50.19 -26:00:17.4 HIP 116547 9.51
2026-02-13 00:00 23:36:55.34 -25:59:39.9 HIP 116547 8.45
2026-02-13 12:00 23:37:00.51 -25:59:02.5 HIP 116547 7.47
2026-02-14 00:00 23:37:05.71 -25:58:25.3 HIP 116547 6.61
2026-02-14 12:00 23:37:10.94 -25:57:48.2 HIP 116547 5.92
2026-02-15 00:00 23:37:16.18 -25:57:11.3 HIP 116547 5.48
2026-02-15 12:00 23:37:21.45 -25:56:34.6 HIP 116547 5.35
2026-02-16 00:00 23:37:26.74 -25:55:58.0 HIP 116547 5.55
2026-02-16 12:00 23:37:32.06 -25:55:21.6 HIP 116547 6.06
2026-02-17 00:00 23:37:37.39 -25:54:45.3 HIP 116547 6.80
2026-02-17 12:00 23:37:42.75 -25:54:09.2 HIP 116547 7.71
2026-02-18 00:00 23:37:48.13 -25:53:33.3 HIP 116547 8.74
2026-02-18 12:00 23:37:53.52 -25:52:57.6 HIP 116547 9.85
2026-02-19 00:00 23:37:58.94 -25:52:22.1 HIP 116547 11.02
2026-02-19 12:00 23:38:04.38 -25:51:46.7 HIP 116547 12.23
2026-02-20 00:00 23:38:09.84 -25:51:11.5 HIP 116547 13.48
2026-02-20 12:00 23:38:15.31 -25:50:36.6 HIP 116547 14.75
2026-02-21 00:00 23:38:20.80 -25:50:01.8 HIP 116547 16.04
2026-02-21 12:00 23:38:26.31 -25:49:27.2 HIP 116547 17.34
2026-02-22 00:00 23:38:31.84 -25:48:52.8 HIP 116547 18.66
2026-02-22 12:00 23:38:37.38 -25:48:18.6 HIP 116547 19.99
2026-02-23 00:00 23:38:42.95 -25:47:44.7 HIP 116547 21.32
2026-02-23 12:00 23:38:48.52 -25:47:10.9 HIP 116547 22.66
2026-02-24 00:00 23:38:54.11 -25:46:37.4 HIP 116547 24.01