P/2018 Y2 (Africano)

메타데이터

항목
Designation P/2018 Y2 (Africano)
Type P
Perihelion (tp_cal, UTC) 2019-01-02T14:21:44.887680Z
Orbit solution date (soln_date, UTC) 2021-05-31T22:43:01Z
Obs used 81
NEO -
M1 10.900
K1 10.000
PC 0.030
Discovery observation (MPC, UTC) 2018-12-31T07:03:45.792000Z
Discovery magnitude (MPC) 19.20 G
Discovery observatory (MPC) G96 · University of Arizona Mt. Lemmon Survey
Osculating 궤도요소
항목
Epoch (epoch_cal, TDB) 2019-01-11.0000000
e 0.47934818
q (au) 3.893253
a (au) 7.477652
i (deg) 11.680345
Ω (om, deg) 297.264911
ω (w, deg) 162.498617
M (ma, deg) 0.404964

밝기

P/2018 Y2 (Africano) · Magnitude (Full range)

산란 + 전체 선형

$$ M_a = (13.087 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

모델 상수

항목
H0 13.087
n 2.000
gf 0.991
gb -0.944
k 1.000
δ90 9.528
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)
2026-06-01 00:00 17:16:52.47 -31:01:23.9 HIP 84611 18.67
2026-06-01 12:00 17:16:41.65 -31:01:10.9 HIP 84611 19.94
2026-06-02 00:00 17:16:30.82 -31:00:57.7 HIP 84611 21.40
2026-06-02 12:00 17:16:19.96 -31:00:44.2 HIP 84611 23.00
2026-06-03 00:00 17:16:09.09 -31:00:30.4 HIP 84381 23.72
2026-06-03 12:00 17:15:58.20 -31:00:16.2 HIP 84381 22.62
2026-06-04 00:00 17:15:47.29 -31:00:01.8 HIP 84381 21.73
2026-06-04 12:00 17:15:36.36 -30:59:47.2 HIP 84381 21.06
2026-06-05 00:00 17:15:25.43 -30:59:32.2 HIP 84318 19.64
2026-06-05 12:00 17:15:14.48 -30:59:16.9 HIP 84318 18.13
2026-06-06 00:00 17:15:03.51 -30:59:01.4 HIP 84318 16.82
2026-06-06 12:00 17:14:52.54 -30:58:45.5 HIP 84318 15.76
2026-06-07 00:00 17:14:41.56 -30:58:29.4 HIP 84318 15.01
2026-06-07 12:00 17:14:30.57 -30:58:13.0 HIP 84318 14.60
2026-06-08 00:00 17:14:19.58 -30:57:56.3 HIP 84318 14.59
2026-06-08 12:00 17:14:08.58 -30:57:39.4 HIP 84318 14.95
2026-06-09 00:00 17:13:57.58 -30:57:22.1 HIP 84318 15.68
2026-06-09 12:00 17:13:46.57 -30:57:04.6 HIP 84318 16.72
2026-06-10 00:00 17:13:35.57 -30:56:46.8 HIP 84318 18.01
2026-06-10 12:00 17:13:24.56 -30:56:28.7 HIP 84142 19.10
2026-06-11 00:00 17:13:13.55 -30:56:10.4 HIP 84142 16.97
2026-06-11 12:00 17:13:02.55 -30:55:51.8 HIP 84142 14.90
2026-06-12 00:00 17:12:51.55 -30:55:32.9 HIP 84142 12.94
2026-06-12 12:00 17:12:40.56 -30:55:13.7 HIP 84142 11.15
2026-06-13 00:00 17:12:29.58 -30:54:54.3 HIP 84142 9.61
2026-06-13 12:00 17:12:18.60 -30:54:34.6 HIP 84142 8.46
2026-06-14 00:00 17:12:07.63 -30:54:14.7 HIP 84142 7.88
2026-06-14 12:00 17:11:56.67 -30:53:54.4 HIP 84142 7.99
2026-06-15 00:00 17:11:45.73 -30:53:34.0 HIP 84142 8.77
2026-06-15 12:00 17:11:34.80 -30:53:13.2 HIP 84142 10.05
2026-06-16 00:00 17:11:23.88 -30:52:52.2 HIP 84142 11.67
2026-06-16 12:00 17:11:12.98 -30:52:31.0 HIP 84142 13.51
2026-06-17 00:00 17:11:02.10 -30:52:09.5 HIP 84142 15.49
2026-06-17 12:00 17:10:51.24 -30:51:47.8 HIP 84142 17.56
2026-06-18 00:00 17:10:40.40 -30:51:25.8 HIP 84142 19.69
2026-06-18 12:00 17:10:29.58 -30:51:03.5 HIP 84142 21.86
2026-06-19 00:00 17:10:18.78 -30:50:41.1 HIP 84142 24.06
2026-06-19 12:00 17:10:08.01 -30:50:18.3 HIP 84142 26.28
2026-06-20 00:00 17:09:57.27 -30:49:55.4 HIP 84142 28.52
2026-06-20 12:00 17:09:46.55 -30:49:32.2 HIP 83896 28.33
2026-06-21 00:00 17:09:35.86 -30:49:08.8 HIP 83896 27.01
2026-06-21 12:00 17:09:25.20 -30:48:45.2 HIP 83896 25.84
2026-06-22 00:00 17:09:14.57 -30:48:21.3 HIP 83896 24.83