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
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
20:27:13.11 |
-16:38:59.1 |
HIP 100730 |
32.12 |
| 2026-05-12 12:00 |
20:27:35.80 |
-16:37:21.5 |
HIP 100730 |
36.13 |
| 2026-05-13 00:00 |
20:27:58.22 |
-16:35:44.7 |
HIP 101190 |
38.78 |
| 2026-05-13 12:00 |
20:28:20.35 |
-16:34:08.7 |
HIP 101190 |
33.40 |
| 2026-05-14 00:00 |
20:28:42.19 |
-16:32:33.5 |
HIP 101190 |
28.15 |
| 2026-05-14 12:00 |
20:29:03.75 |
-16:30:59.1 |
HIP 101190 |
23.08 |
| 2026-05-15 00:00 |
20:29:25.02 |
-16:29:25.6 |
HIP 101190 |
18.25 |
| 2026-05-15 12:00 |
20:29:45.99 |
-16:27:52.9 |
HIP 101190 |
13.86 |
| 2026-05-16 00:00 |
20:30:06.67 |
-16:26:21.1 |
HIP 101190 |
10.36 |
| 2026-05-16 12:00 |
20:30:27.06 |
-16:24:50.2 |
HIP 101190 |
8.74 |
| 2026-05-17 00:00 |
20:30:47.14 |
-16:23:20.3 |
HIP 101190 |
9.87 |
| 2026-05-17 12:00 |
20:31:06.93 |
-16:21:51.2 |
HIP 101190 |
12.96 |
| 2026-05-18 00:00 |
20:31:26.41 |
-16:20:23.1 |
HIP 101190 |
16.91 |
| 2026-05-18 12:00 |
20:31:45.59 |
-16:18:56.0 |
HIP 101357 |
20.80 |
| 2026-05-19 00:00 |
20:32:04.46 |
-16:17:29.9 |
HIP 101357 |
20.15 |
| 2026-05-19 12:00 |
20:32:23.02 |
-16:16:04.7 |
HIP 101409 |
17.65 |
| 2026-05-20 00:00 |
20:32:41.28 |
-16:14:40.6 |
HIP 101409 |
14.28 |
| 2026-05-20 12:00 |
20:32:59.22 |
-16:13:17.5 |
HIP 101409 |
11.81 |
| 2026-05-21 00:00 |
20:33:16.85 |
-16:11:55.4 |
HIP 101409 |
10.76 |
| 2026-05-21 12:00 |
20:33:34.17 |
-16:10:34.4 |
HIP 101409 |
11.45 |
| 2026-05-22 00:00 |
20:33:51.17 |
-16:09:14.4 |
HIP 101409 |
13.53 |
| 2026-05-22 12:00 |
20:34:07.85 |
-16:07:55.5 |
HIP 101409 |
16.43 |
| 2026-05-23 00:00 |
20:34:24.22 |
-16:06:37.8 |
HIP 101409 |
19.74 |
| 2026-05-23 12:00 |
20:34:40.26 |
-16:05:21.1 |
HIP 101555 |
17.66 |
| 2026-05-24 00:00 |
20:34:55.98 |
-16:04:05.5 |
HIP 101555 |
16.31 |
| 2026-05-24 12:00 |
20:35:11.37 |
-16:02:51.1 |
HIP 101555 |
15.87 |
| 2026-05-25 00:00 |
20:35:26.44 |
-16:01:37.9 |
HIP 101555 |
16.34 |
| 2026-05-25 12:00 |
20:35:41.18 |
-16:00:25.8 |
HIP 101555 |
17.60 |
| 2026-05-26 00:00 |
20:35:55.59 |
-15:59:14.9 |
HIP 101555 |
19.47 |
| 2026-05-26 12:00 |
20:36:09.67 |
-15:58:05.2 |
HIP 101555 |
21.73 |
| 2026-05-27 00:00 |
20:36:23.42 |
-15:56:56.7 |
HIP 101555 |
24.24 |
| 2026-05-27 12:00 |
20:36:36.83 |
-15:55:49.4 |
HIP 101555 |
26.90 |
| 2026-05-28 00:00 |
20:36:49.90 |
-15:54:43.4 |
HIP 101555 |
29.65 |
| 2026-05-28 12:00 |
20:37:02.63 |
-15:53:38.6 |
HIP 101555 |
32.42 |
| 2026-05-29 00:00 |
20:37:15.03 |
-15:52:35.1 |
HIP 101555 |
35.20 |
| 2026-05-29 12:00 |
20:37:27.08 |
-15:51:32.8 |
HIP 101649 |
36.80 |
| 2026-05-30 00:00 |
20:37:38.78 |
-15:50:31.9 |
HIP 101649 |
37.28 |
| 2026-05-30 12:00 |
20:37:50.14 |
-15:49:32.3 |
HIP 101649 |
37.96 |
| 2026-05-31 00:00 |
20:38:01.15 |
-15:48:34.0 |
HIP 101649 |
38.81 |
| 2026-05-31 12:00 |
20:38:11.81 |
-15:47:37.1 |
HIP 101999 |
38.42 |
| 2026-06-01 00:00 |
20:38:22.12 |
-15:46:41.5 |
HIP 101999 |
35.95 |
| 2026-06-01 12:00 |
20:38:32.07 |
-15:45:47.3 |
HIP 101999 |
33.58 |
| 2026-06-02 00:00 |
20:38:41.66 |
-15:44:54.5 |
HIP 101999 |
31.32 |