C/2017 M4 (ATLAS)

메타데이터

항목
Designation C/2017 M4 (ATLAS)
Type C
Perihelion (tp_cal, UTC) 2019-01-18T08:09:45.547200Z
Orbit solution date (soln_date, UTC) 2022-07-31T01:42:28Z
Obs used 3296
NEO -
M1 9.400
K1 6.000
PC -
Osculating 궤도요소
항목
Epoch (epoch_cal, TDB) 2018-06-17.0000000
e 1.00108487
q (au) 3.251701
a (au) -2997.319774
i (deg) 105.657087
Ω (om, deg) 65.868353
ω (w, deg) 167.652626
M (ma, deg) -0.001293

밝기

C/2017 M4 (ATLAS) · Magnitude (Full range)

산란 + 전체 선형

$$ M_a = (7.294 + 2.998\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

모델 상수

항목
H0 7.294
n 2.998
gf 0.999
gb -1.000
k 1.000
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

천체력

Date/Time (UTC) RA (J2000) Dec (J2000) Nearest HIP Dist from HIP (arcmin)
2026-07-29 00:00 06:14:10.37 -32:16:51.7 HIP 29475 19.87
2026-07-29 12:00 06:14:15.79 -32:17:23.5 HIP 29475 21.09
2026-07-30 00:00 06:14:21.17 -32:17:55.9 HIP 29710 20.16
2026-07-30 12:00 06:14:26.53 -32:18:28.9 HIP 29710 18.97
2026-07-31 00:00 06:14:31.85 -32:19:02.3 HIP 29710 17.80
2026-07-31 12:00 06:14:37.14 -32:19:36.2 HIP 29710 16.63
2026-08-01 00:00 06:14:42.39 -32:20:10.6 HIP 29710 15.47
2026-08-01 12:00 06:14:47.61 -32:20:45.5 HIP 29710 14.33
2026-08-02 00:00 06:14:52.80 -32:21:20.9 HIP 29710 13.20
2026-08-02 12:00 06:14:57.96 -32:21:56.8 HIP 29710 12.09
2026-08-03 00:00 06:15:03.08 -32:22:33.2 HIP 29710 11.01
2026-08-03 12:00 06:15:08.16 -32:23:10.0 HIP 29710 9.96
2026-08-04 00:00 06:15:13.21 -32:23:47.4 HIP 29710 8.95
2026-08-04 12:00 06:15:18.23 -32:24:25.2 HIP 29710 8.01
2026-08-05 00:00 06:15:23.21 -32:25:03.5 HIP 29710 7.14
2026-08-05 12:00 06:15:28.15 -32:25:42.3 HIP 29710 6.38
2026-08-06 00:00 06:15:33.06 -32:26:21.6 HIP 29710 5.78
2026-08-06 12:00 06:15:37.93 -32:27:01.3 HIP 29710 5.39
2026-08-07 00:00 06:15:42.76 -32:27:41.6 HIP 29710 5.24
2026-08-07 12:00 06:15:47.55 -32:28:22.2 HIP 29710 5.37
2026-08-08 00:00 06:15:52.31 -32:29:03.4 HIP 29710 5.74
2026-08-08 12:00 06:15:57.03 -32:29:45.0 HIP 29710 6.32
2026-08-09 00:00 06:16:01.71 -32:30:27.1 HIP 29802 6.85
2026-08-09 12:00 06:16:06.35 -32:31:09.6 HIP 29802 6.59
2026-08-10 00:00 06:16:10.95 -32:31:52.6 HIP 29802 6.55
2026-08-10 12:00 06:16:15.51 -32:32:36.0 HIP 29802 6.74
2026-08-11 00:00 06:16:20.03 -32:33:19.9 HIP 29802 7.14
2026-08-11 12:00 06:16:24.51 -32:34:04.2 HIP 29802 7.72
2026-08-12 00:00 06:16:28.94 -32:34:48.9 HIP 29802 8.43
2026-08-12 12:00 06:16:33.34 -32:35:34.1 HIP 29802 9.25
2026-08-13 00:00 06:16:37.69 -32:36:19.8 HIP 29802 10.16
2026-08-13 12:00 06:16:42.00 -32:37:05.8 HIP 29802 11.12
2026-08-14 00:00 06:16:46.27 -32:37:52.3 HIP 29802 12.12
2026-08-14 12:00 06:16:50.50 -32:38:39.2 HIP 29802 13.16
2026-08-15 00:00 06:16:54.68 -32:39:26.5 HIP 29802 14.23
2026-08-15 12:00 06:16:58.81 -32:40:14.3 HIP 29802 15.31
2026-08-16 00:00 06:17:02.91 -32:41:02.4 HIP 29802 16.41
2026-08-16 12:00 06:17:06.96 -32:41:51.0 HIP 29802 17.52
2026-08-17 00:00 06:17:10.96 -32:42:39.9 HIP 29802 18.64
2026-08-17 12:00 06:17:14.92 -32:43:29.3 HIP 29802 19.77
2026-08-18 00:00 06:17:18.83 -32:44:19.0 HIP 29802 20.90
2026-08-18 12:00 06:17:22.70 -32:45:09.2 HIP 29802 22.04
2026-08-19 00:00 06:17:26.52 -32:45:59.7 HIP 29802 23.17