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 · 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

$$ M_a = (12.918 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

모델 상수

항목
H0 12.918
n 2.000
gf 1.000
gb -0.509
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)
2026-05-12 00:00 17:23:33.84 -31:06:01.3 HIP 84995 19.35
2026-05-12 12:00 17:23:24.86 -31:06:00.0 HIP 84995 17.88
2026-05-13 00:00 17:23:15.82 -31:05:58.4 HIP 84995 16.50
2026-05-13 12:00 17:23:06.70 -31:05:56.5 HIP 84995 15.23
2026-05-14 00:00 17:22:57.52 -31:05:54.4 HIP 84995 14.12
2026-05-14 12:00 17:22:48.27 -31:05:51.9 HIP 84995 13.21
2026-05-15 00:00 17:22:38.96 -31:05:49.2 HIP 84995 12.54
2026-05-15 12:00 17:22:29.59 -31:05:46.2 HIP 84995 12.17
2026-05-16 00:00 17:22:20.15 -31:05:42.9 HIP 84995 12.13
2026-05-16 12:00 17:22:10.65 -31:05:39.4 HIP 84995 12.43
2026-05-17 00:00 17:22:01.09 -31:05:35.5 HIP 84995 13.06
2026-05-17 12:00 17:21:51.47 -31:05:31.4 HIP 84995 13.96
2026-05-18 00:00 17:21:41.80 -31:05:26.9 HIP 84995 15.11
2026-05-18 12:00 17:21:32.07 -31:05:22.2 HIP 84995 16.45
2026-05-19 00:00 17:21:22.28 -31:05:17.2 HIP 84995 17.94
2026-05-19 12:00 17:21:12.44 -31:05:11.9 HIP 84995 19.56
2026-05-20 00:00 17:21:02.55 -31:05:06.3 HIP 84995 21.27
2026-05-20 12:00 17:20:52.60 -31:05:00.4 HIP 84995 23.07
2026-05-21 00:00 17:20:42.60 -31:04:54.3 HIP 84734 24.90
2026-05-21 12:00 17:20:32.56 -31:04:47.8 HIP 84734 23.43
2026-05-22 00:00 17:20:22.47 -31:04:41.0 HIP 84734 22.08
2026-05-22 12:00 17:20:12.33 -31:04:34.0 HIP 84734 20.86
2026-05-23 00:00 17:20:02.15 -31:04:26.6 HIP 84734 19.81
2026-05-23 12:00 17:19:51.92 -31:04:19.0 HIP 84734 18.95
2026-05-24 00:00 17:19:41.65 -31:04:11.0 HIP 84734 18.31
2026-05-24 12:00 17:19:31.33 -31:04:02.8 HIP 84734 17.93
2026-05-25 00:00 17:19:20.98 -31:03:54.3 HIP 84734 17.82
2026-05-25 12:00 17:19:10.59 -31:03:45.4 HIP 84734 17.99
2026-05-26 00:00 17:19:00.16 -31:03:36.3 HIP 84734 18.43
2026-05-26 12:00 17:18:49.69 -31:03:26.9 HIP 84734 19.13
2026-05-27 00:00 17:18:39.19 -31:03:17.2 HIP 84734 20.07
2026-05-27 12:00 17:18:28.65 -31:03:07.2 HIP 84611 19.51
2026-05-28 00:00 17:18:18.08 -31:02:56.9 HIP 84611 18.32
2026-05-28 12:00 17:18:07.48 -31:02:46.3 HIP 84611 17.35
2026-05-29 00:00 17:17:56.85 -31:02:35.4 HIP 84611 16.62
2026-05-29 12:00 17:17:46.18 -31:02:24.2 HIP 84611 16.19
2026-05-30 00:00 17:17:35.49 -31:02:12.8 HIP 84611 16.07
2026-05-30 12:00 17:17:24.78 -31:02:01.0 HIP 84611 16.27
2026-05-31 00:00 17:17:14.03 -31:01:48.9 HIP 84611 16.79
2026-05-31 12:00 17:17:03.26 -31:01:36.5 HIP 84611 17.60
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