메타데이터
| 항목 |
값 |
| Designation |
P/2021 R8 (Sheppard) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-10-07T12:21:16.145280Z |
| Orbit solution date (soln_date, UTC) |
2021-12-07T11:12:02Z |
| Obs used |
26 |
| NEO |
- |
| M1 |
18.600 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-09-05T13:08:45.772800Z |
| Discovery magnitude (MPC) |
21.69 G |
| Discovery observatory (MPC) |
T09 · Subaru Telescope, Maunakea |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2021-09-16.0000000 |
| e |
0.29404210 |
| q (au) |
2.130978 |
| a (au) |
3.018562 |
| i (deg) |
2.203054 |
| Ω (om, deg) |
167.025325 |
| ω (w, deg) |
190.793883 |
| M (ma, deg) |
355.956657 |
밝기
산란 + 전체 선형
$$
M_a = (16.419 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
16.419 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.900 |
| 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
찾아보기
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
19:58:54.60 |
-19:10:42.3 |
HIP 98634 |
44.32 |
| 2026-09-20 12:00 |
19:59:06.65 |
-19:10:53.5 |
HIP 98634 |
41.52 |
| 2026-09-21 00:00 |
19:59:19.17 |
-19:11:03.2 |
HIP 98634 |
38.60 |
| 2026-09-21 12:00 |
19:59:32.14 |
-19:11:11.4 |
HIP 98634 |
35.59 |
| 2026-09-22 00:00 |
19:59:45.58 |
-19:11:18.0 |
HIP 98634 |
32.47 |
| 2026-09-22 12:00 |
19:59:59.47 |
-19:11:23.2 |
HIP 98634 |
29.26 |
| 2026-09-23 00:00 |
20:00:13.82 |
-19:11:26.8 |
HIP 98634 |
25.95 |
| 2026-09-23 12:00 |
20:00:28.62 |
-19:11:28.9 |
HIP 98634 |
22.55 |
| 2026-09-24 00:00 |
20:00:43.87 |
-19:11:29.5 |
HIP 98634 |
19.08 |
| 2026-09-24 12:00 |
20:00:59.58 |
-19:11:28.6 |
HIP 98634 |
15.57 |
| 2026-09-25 00:00 |
20:01:15.72 |
-19:11:26.1 |
HIP 98634 |
12.06 |
| 2026-09-25 12:00 |
20:01:32.32 |
-19:11:22.1 |
HIP 98634 |
8.71 |
| 2026-09-26 00:00 |
20:01:49.35 |
-19:11:16.6 |
HIP 98634 |
6.02 |
| 2026-09-26 12:00 |
20:02:06.82 |
-19:11:09.5 |
HIP 98634 |
5.38 |
| 2026-09-27 00:00 |
20:02:24.73 |
-19:11:00.9 |
HIP 98634 |
7.52 |
| 2026-09-27 12:00 |
20:02:43.07 |
-19:10:50.8 |
HIP 98634 |
11.04 |
| 2026-09-28 00:00 |
20:03:01.85 |
-19:10:39.1 |
HIP 98634 |
15.08 |
| 2026-09-28 12:00 |
20:03:21.05 |
-19:10:25.9 |
HIP 98634 |
19.39 |
| 2026-09-29 00:00 |
20:03:40.68 |
-19:10:11.1 |
HIP 98634 |
23.88 |
| 2026-09-29 12:00 |
20:04:00.74 |
-19:09:54.8 |
HIP 98901 |
27.73 |
| 2026-09-30 00:00 |
20:04:21.21 |
-19:09:36.9 |
HIP 98901 |
25.26 |
| 2026-09-30 12:00 |
20:04:42.11 |
-19:09:17.4 |
HIP 98901 |
23.50 |
| 2026-10-01 00:00 |
20:05:03.42 |
-19:08:56.4 |
HIP 98901 |
22.67 |
| 2026-10-01 12:00 |
20:05:25.15 |
-19:08:33.8 |
HIP 98901 |
22.94 |
| 2026-10-02 00:00 |
20:05:47.29 |
-19:08:09.7 |
HIP 98901 |
24.35 |
| 2026-10-02 12:00 |
20:06:09.85 |
-19:07:44.0 |
HIP 99096 |
21.95 |
| 2026-10-03 00:00 |
20:06:32.81 |
-19:07:16.7 |
HIP 99096 |
19.65 |
| 2026-10-03 12:00 |
20:06:56.18 |
-19:06:47.8 |
HIP 99096 |
18.70 |
| 2026-10-04 00:00 |
20:07:19.95 |
-19:06:17.3 |
HIP 99096 |
19.41 |
| 2026-10-04 12:00 |
20:07:44.12 |
-19:05:45.2 |
HIP 99193 |
18.81 |
| 2026-10-05 00:00 |
20:08:08.69 |
-19:05:11.5 |
HIP 99193 |
16.99 |
| 2026-10-05 12:00 |
20:08:33.66 |
-19:04:36.2 |
HIP 99193 |
17.09 |
| 2026-10-06 00:00 |
20:08:59.03 |
-19:03:59.3 |
HIP 99193 |
19.15 |
| 2026-10-06 12:00 |
20:09:24.79 |
-19:03:20.7 |
HIP 99193 |
22.73 |
| 2026-10-07 00:00 |
20:09:50.93 |
-19:02:40.6 |
HIP 99391 |
21.89 |
| 2026-10-07 12:00 |
20:10:17.47 |
-19:01:58.8 |
HIP 99391 |
21.09 |
| 2026-10-08 00:00 |
20:10:44.39 |
-19:01:15.4 |
HIP 99391 |
22.19 |
| 2026-10-08 12:00 |
20:11:11.70 |
-19:00:30.3 |
HIP 99391 |
24.99 |
| 2026-10-09 00:00 |
20:11:39.38 |
-18:59:43.6 |
HIP 99391 |
29.08 |
| 2026-10-09 12:00 |
20:12:07.44 |
-18:58:55.3 |
HIP 99391 |
34.05 |
| 2026-10-10 00:00 |
20:12:35.88 |
-18:58:05.3 |
HIP 99782 |
33.24 |
| 2026-10-10 12:00 |
20:13:04.69 |
-18:57:13.6 |
HIP 99782 |
27.72 |
| 2026-10-11 00:00 |
20:13:33.87 |
-18:56:20.3 |
HIP 99782 |
22.89 |