메타데이터
| 항목 |
값 |
| Designation |
C/2017 U7 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-09-11T17:19:45.906240Z |
| Orbit solution date (soln_date, UTC) |
2024-05-30T01:12:17Z |
| Obs used |
915 |
| NEO |
- |
| M1 |
6.300 |
| K1 |
8.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2017-10-29T07:49:16.032000Z |
| Discovery magnitude (MPC) |
20.10 i |
| Discovery observatory (MPC) |
F51 · Pan-STARRS 1, Haleakala |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2020-01-08.0000000 |
| e |
1.00164840 |
| q (au) |
6.417510 |
| a (au) |
-3893.179319 |
| i (deg) |
142.635219 |
| Ω (om, deg) |
276.232353 |
| ω (w, deg) |
326.068994 |
| M (ma, deg) |
0.000480 |
밝기
산란 + 전체 선형
$$
M_a = (-0.376 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
-0.376 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.958 |
| 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
잔차 (구간 선형)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 시작일 (UTC) |
끝 (UTC) |
a |
b |
| 2017-08-18 |
2019-09-07 |
+24.0875 |
-19.664 |
| 2019-09-15 |
2022-08-03 |
+3.9040 |
-3.583 |
log10 r = log10(태양거리/AU), Δ = 지구거리(AU)
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
15:05:09.63 |
+20:01:19.1 |
HIP 73748 |
14.38 |
| 2026-03-26 12:00 |
15:05:02.26 |
+20:02:43.9 |
HIP 73748 |
14.48 |
| 2026-03-27 00:00 |
15:04:54.83 |
+20:04:08.3 |
HIP 73748 |
14.91 |
| 2026-03-27 12:00 |
15:04:47.35 |
+20:05:32.5 |
HIP 73748 |
15.64 |
| 2026-03-28 00:00 |
15:04:39.82 |
+20:06:56.3 |
HIP 73748 |
16.64 |
| 2026-03-28 12:00 |
15:04:32.24 |
+20:08:19.8 |
HIP 73748 |
17.86 |
| 2026-03-29 00:00 |
15:04:24.62 |
+20:09:43.0 |
HIP 73748 |
19.27 |
| 2026-03-29 12:00 |
15:04:16.94 |
+20:11:05.8 |
HIP 73748 |
20.83 |
| 2026-03-30 00:00 |
15:04:09.22 |
+20:12:28.3 |
HIP 73748 |
22.50 |
| 2026-03-30 12:00 |
15:04:01.45 |
+20:13:50.4 |
HIP 73610 |
21.87 |
| 2026-03-31 00:00 |
15:03:53.63 |
+20:15:12.2 |
HIP 73610 |
19.59 |
| 2026-03-31 12:00 |
15:03:45.77 |
+20:16:33.6 |
HIP 73610 |
17.30 |
| 2026-04-01 00:00 |
15:03:37.86 |
+20:17:54.7 |
HIP 73610 |
15.01 |
| 2026-04-01 12:00 |
15:03:29.91 |
+20:19:15.4 |
HIP 73610 |
12.71 |
| 2026-04-02 00:00 |
15:03:21.91 |
+20:20:35.7 |
HIP 73610 |
10.40 |
| 2026-04-02 12:00 |
15:03:13.87 |
+20:21:55.7 |
HIP 73610 |
8.10 |
| 2026-04-03 00:00 |
15:03:05.78 |
+20:23:15.2 |
HIP 73610 |
5.78 |
| 2026-04-03 12:00 |
15:02:57.65 |
+20:24:34.4 |
HIP 73610 |
3.47 |
| 2026-04-04 00:00 |
15:02:49.48 |
+20:25:53.1 |
HIP 73610 |
1.15 |
| 2026-04-04 12:00 |
15:02:41.27 |
+20:27:11.5 |
HIP 73610 |
1.18 |
| 2026-04-05 00:00 |
15:02:33.02 |
+20:28:29.4 |
HIP 73610 |
3.51 |
| 2026-04-05 12:00 |
15:02:24.72 |
+20:29:47.0 |
HIP 73610 |
5.84 |
| 2026-04-06 00:00 |
15:02:16.39 |
+20:31:04.1 |
HIP 73610 |
8.18 |
| 2026-04-06 12:00 |
15:02:08.01 |
+20:32:20.8 |
HIP 73610 |
10.52 |
| 2026-04-07 00:00 |
15:01:59.60 |
+20:33:37.0 |
HIP 73610 |
12.86 |
| 2026-04-07 12:00 |
15:01:51.15 |
+20:34:52.8 |
HIP 73610 |
15.21 |
| 2026-04-08 00:00 |
15:01:42.66 |
+20:36:08.2 |
HIP 73610 |
17.56 |
| 2026-04-08 12:00 |
15:01:34.13 |
+20:37:23.1 |
HIP 73610 |
19.91 |
| 2026-04-09 00:00 |
15:01:25.57 |
+20:38:37.6 |
HIP 73610 |
22.27 |
| 2026-04-09 12:00 |
15:01:16.97 |
+20:39:51.6 |
HIP 73610 |
24.63 |
| 2026-04-10 00:00 |
15:01:08.33 |
+20:41:05.1 |
HIP 73610 |
26.99 |
| 2026-04-10 12:00 |
15:00:59.66 |
+20:42:18.2 |
HIP 73610 |
29.35 |
| 2026-04-11 00:00 |
15:00:50.96 |
+20:43:30.8 |
HIP 73355 |
28.79 |
| 2026-04-11 12:00 |
15:00:42.22 |
+20:44:42.9 |
HIP 73355 |
28.39 |
| 2026-04-12 00:00 |
15:00:33.45 |
+20:45:54.5 |
HIP 73355 |
28.17 |
| 2026-04-12 12:00 |
15:00:24.65 |
+20:47:05.6 |
HIP 73355 |
28.15 |
| 2026-04-13 00:00 |
15:00:15.82 |
+20:48:16.3 |
HIP 73355 |
28.31 |
| 2026-04-13 12:00 |
15:00:06.95 |
+20:49:26.4 |
HIP 73355 |
28.66 |
| 2026-04-14 00:00 |
14:59:58.06 |
+20:50:36.0 |
HIP 73235 |
26.78 |
| 2026-04-14 12:00 |
14:59:49.13 |
+20:51:45.1 |
HIP 73235 |
24.61 |
| 2026-04-15 00:00 |
14:59:40.18 |
+20:52:53.7 |
HIP 73235 |
22.47 |
| 2026-04-15 12:00 |
14:59:31.20 |
+20:54:01.7 |
HIP 73235 |
20.39 |
| 2026-04-16 00:00 |
14:59:22.19 |
+20:55:09.3 |
HIP 73235 |
18.36 |