메타데이터
| 항목 |
값 |
| Designation |
C/1987 P1 (Bradfield) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1987-11-07T06:34:43.440960Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:33Z |
| Obs used |
611 |
| NEO |
- |
| M1 |
6.000 |
| K1 |
8.500 |
| PC |
- |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
1987-11-29.0000000 |
| e |
0.99473713 |
| q (au) |
0.868956 |
| a (au) |
165.110625 |
| i (deg) |
34.088067 |
| Ω (om, deg) |
268.092924 |
| ω (w, deg) |
73.899611 |
| M (ma, deg) |
0.010093 |
밝기
산란 + 전체 선형
$$
M_a = (5.750 + 2.678\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
5.750 |
| n |
2.678 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
1.000 |
| 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 |
| 1987-08-12 |
1987-11-06 |
+1.8670 |
+0.018 |
| 1987-11-07 |
1987-12-09 |
+1.4060 |
+0.081 |
| 1987-12-09 |
1988-03-08 |
-0.4160 |
+0.009 |
| 1988-03-08 |
1988-04-11 |
+8.3598 |
-2.815 |
log10 r = log10(태양거리/AU), Δ = 지구거리(AU)
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
09:08:53.71 |
-14:10:09.8 |
HIP 44859 |
7.06 |
| 2026-07-29 12:00 |
09:08:55.60 |
-14:10:15.1 |
HIP 44859 |
7.53 |
| 2026-07-30 00:00 |
09:08:57.50 |
-14:10:20.6 |
HIP 44859 |
8.00 |
| 2026-07-30 12:00 |
09:08:59.39 |
-14:10:26.2 |
HIP 44859 |
8.47 |
| 2026-07-31 00:00 |
09:09:01.29 |
-14:10:31.9 |
HIP 44859 |
8.93 |
| 2026-07-31 12:00 |
09:09:03.19 |
-14:10:37.8 |
HIP 44859 |
9.41 |
| 2026-08-01 00:00 |
09:09:05.09 |
-14:10:43.8 |
HIP 44859 |
9.88 |
| 2026-08-01 12:00 |
09:09:06.99 |
-14:10:49.9 |
HIP 44859 |
10.35 |
| 2026-08-02 00:00 |
09:09:08.90 |
-14:10:56.1 |
HIP 44859 |
10.82 |
| 2026-08-02 12:00 |
09:09:10.80 |
-14:11:02.5 |
HIP 44859 |
11.30 |
| 2026-08-03 00:00 |
09:09:12.71 |
-14:11:09.0 |
HIP 44859 |
11.77 |
| 2026-08-03 12:00 |
09:09:14.62 |
-14:11:15.6 |
HIP 44859 |
12.25 |
| 2026-08-04 00:00 |
09:09:16.52 |
-14:11:22.3 |
HIP 44859 |
12.72 |
| 2026-08-04 12:00 |
09:09:18.43 |
-14:11:29.2 |
HIP 44859 |
13.20 |
| 2026-08-05 00:00 |
09:09:20.34 |
-14:11:36.2 |
HIP 44859 |
13.68 |
| 2026-08-05 12:00 |
09:09:22.25 |
-14:11:43.3 |
HIP 44859 |
14.15 |
| 2026-08-06 00:00 |
09:09:24.17 |
-14:11:50.6 |
HIP 44859 |
14.63 |
| 2026-08-06 12:00 |
09:09:26.08 |
-14:11:57.9 |
HIP 44859 |
15.11 |
| 2026-08-07 00:00 |
09:09:27.99 |
-14:12:05.4 |
HIP 44859 |
15.59 |
| 2026-08-07 12:00 |
09:09:29.90 |
-14:12:13.0 |
HIP 44859 |
16.07 |
| 2026-08-08 00:00 |
09:09:31.82 |
-14:12:20.8 |
HIP 44859 |
16.55 |
| 2026-08-08 12:00 |
09:09:33.73 |
-14:12:28.6 |
HIP 44859 |
17.03 |
| 2026-08-09 00:00 |
09:09:35.64 |
-14:12:36.6 |
HIP 44859 |
17.51 |
| 2026-08-09 12:00 |
09:09:37.55 |
-14:12:44.7 |
HIP 44859 |
18.00 |
| 2026-08-10 00:00 |
09:09:39.46 |
-14:12:52.9 |
HIP 44859 |
18.48 |
| 2026-08-10 12:00 |
09:09:41.37 |
-14:13:01.2 |
HIP 44859 |
18.96 |
| 2026-08-11 00:00 |
09:09:43.28 |
-14:13:09.7 |
HIP 44859 |
19.44 |
| 2026-08-11 12:00 |
09:09:45.19 |
-14:13:18.3 |
HIP 44859 |
19.93 |
| 2026-08-12 00:00 |
09:09:47.10 |
-14:13:27.0 |
HIP 44859 |
20.41 |
| 2026-08-12 12:00 |
09:09:49.01 |
-14:13:35.8 |
HIP 44859 |
20.90 |
| 2026-08-13 00:00 |
09:09:50.91 |
-14:13:44.7 |
HIP 44859 |
21.38 |
| 2026-08-13 12:00 |
09:09:52.82 |
-14:13:53.8 |
HIP 44859 |
21.86 |
| 2026-08-14 00:00 |
09:09:54.72 |
-14:14:02.9 |
HIP 44859 |
22.35 |
| 2026-08-14 12:00 |
09:09:56.62 |
-14:14:12.2 |
HIP 44859 |
22.83 |
| 2026-08-15 00:00 |
09:09:58.52 |
-14:14:21.6 |
HIP 44974 |
23.31 |
| 2026-08-15 12:00 |
09:10:00.42 |
-14:14:31.1 |
HIP 44974 |
23.55 |
| 2026-08-16 00:00 |
09:10:02.31 |
-14:14:40.8 |
HIP 44974 |
23.80 |
| 2026-08-16 12:00 |
09:10:04.20 |
-14:14:50.5 |
HIP 44974 |
24.07 |
| 2026-08-17 00:00 |
09:10:06.09 |
-14:15:00.3 |
HIP 44974 |
24.34 |
| 2026-08-17 12:00 |
09:10:07.98 |
-14:15:10.3 |
HIP 44974 |
24.61 |
| 2026-08-18 00:00 |
09:10:09.87 |
-14:15:20.4 |
HIP 44974 |
24.90 |
| 2026-08-18 12:00 |
09:10:11.75 |
-14:15:30.5 |
HIP 44974 |
25.20 |
| 2026-08-19 00:00 |
09:10:13.63 |
-14:15:40.8 |
HIP 44974 |
25.50 |