메타데이터
| 항목 |
값 |
| Designation |
90P/Gehrels 1 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2017-06-19T06:36:36.149760Z |
| Orbit solution date (soln_date, UTC) |
2022-05-24T23:57:55Z |
| Obs used |
577 |
| NEO |
- |
| M1 |
7.000 |
| K1 |
18.000 |
| PC |
0.030 |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2017-02-16.0000000 |
| e |
0.50979286 |
| q (au) |
2.974897 |
| a (au) |
6.068654 |
| i (deg) |
9.635376 |
| Ω (om, deg) |
13.251828 |
| ω (w, deg) |
29.270027 |
| M (ma, deg) |
351.872780 |
밝기
산란 + 전체 선형
$$
M_a = (8.608 + 4.725\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
8.608 |
| n |
4.725 |
| gf |
1.000 |
| gb |
-0.828 |
| 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 |
| 2016-08-27 |
2017-01-18 |
+56.4715 |
-28.048 |
| 2017-07-30 |
2018-04-15 |
-5.8039 |
+3.002 |
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 |
15:05:45.10 |
-24:43:22.8 |
HIP 73932 |
11.94 |
| 2026-07-29 12:00 |
15:05:45.15 |
-24:43:04.8 |
HIP 73932 |
12.09 |
| 2026-07-30 00:00 |
15:05:45.31 |
-24:42:47.2 |
HIP 73932 |
12.22 |
| 2026-07-30 12:00 |
15:05:45.59 |
-24:42:30.1 |
HIP 73932 |
12.33 |
| 2026-07-31 00:00 |
15:05:46.00 |
-24:42:13.4 |
HIP 73932 |
12.42 |
| 2026-07-31 12:00 |
15:05:46.52 |
-24:41:57.1 |
HIP 73932 |
12.49 |
| 2026-08-01 00:00 |
15:05:47.16 |
-24:41:41.3 |
HIP 73932 |
12.54 |
| 2026-08-01 12:00 |
15:05:47.91 |
-24:41:26.0 |
HIP 73932 |
12.57 |
| 2026-08-02 00:00 |
15:05:48.79 |
-24:41:11.1 |
HIP 73932 |
12.59 |
| 2026-08-02 12:00 |
15:05:49.78 |
-24:40:56.6 |
HIP 73932 |
12.59 |
| 2026-08-03 00:00 |
15:05:50.89 |
-24:40:42.6 |
HIP 73932 |
12.57 |
| 2026-08-03 12:00 |
15:05:52.12 |
-24:40:29.1 |
HIP 73932 |
12.54 |
| 2026-08-04 00:00 |
15:05:53.47 |
-24:40:16.0 |
HIP 73932 |
12.50 |
| 2026-08-04 12:00 |
15:05:54.93 |
-24:40:03.3 |
HIP 73932 |
12.44 |
| 2026-08-05 00:00 |
15:05:56.51 |
-24:39:51.1 |
HIP 73932 |
12.37 |
| 2026-08-05 12:00 |
15:05:58.21 |
-24:39:39.4 |
HIP 73932 |
12.30 |
| 2026-08-06 00:00 |
15:06:00.03 |
-24:39:28.1 |
HIP 73932 |
12.22 |
| 2026-08-06 12:00 |
15:06:01.96 |
-24:39:17.3 |
HIP 73932 |
12.13 |
| 2026-08-07 00:00 |
15:06:04.01 |
-24:39:07.0 |
HIP 73932 |
12.05 |
| 2026-08-07 12:00 |
15:06:06.18 |
-24:38:57.1 |
HIP 73932 |
11.96 |
| 2026-08-08 00:00 |
15:06:08.46 |
-24:38:47.7 |
HIP 73932 |
11.88 |
| 2026-08-08 12:00 |
15:06:10.86 |
-24:38:38.7 |
HIP 73932 |
11.81 |
| 2026-08-09 00:00 |
15:06:13.38 |
-24:38:30.2 |
HIP 73932 |
11.74 |
| 2026-08-09 12:00 |
15:06:16.01 |
-24:38:22.2 |
HIP 73932 |
11.70 |
| 2026-08-10 00:00 |
15:06:18.76 |
-24:38:14.6 |
HIP 73932 |
11.67 |
| 2026-08-10 12:00 |
15:06:21.63 |
-24:38:07.5 |
HIP 73932 |
11.66 |
| 2026-08-11 00:00 |
15:06:24.61 |
-24:38:00.9 |
HIP 73932 |
11.68 |
| 2026-08-11 12:00 |
15:06:27.71 |
-24:37:54.7 |
HIP 73932 |
11.73 |
| 2026-08-12 00:00 |
15:06:30.92 |
-24:37:49.0 |
HIP 73932 |
11.82 |
| 2026-08-12 12:00 |
15:06:34.25 |
-24:37:43.8 |
HIP 73932 |
11.94 |
| 2026-08-13 00:00 |
15:06:37.69 |
-24:37:39.1 |
HIP 73932 |
12.11 |
| 2026-08-13 12:00 |
15:06:41.25 |
-24:37:34.8 |
HIP 73932 |
12.33 |
| 2026-08-14 00:00 |
15:06:44.92 |
-24:37:31.0 |
HIP 73932 |
12.59 |
| 2026-08-14 12:00 |
15:06:48.70 |
-24:37:27.6 |
HIP 73932 |
12.90 |
| 2026-08-15 00:00 |
15:06:52.60 |
-24:37:24.8 |
HIP 73932 |
13.27 |
| 2026-08-15 12:00 |
15:06:56.61 |
-24:37:22.4 |
HIP 73932 |
13.68 |
| 2026-08-16 00:00 |
15:07:00.74 |
-24:37:20.4 |
HIP 73932 |
14.15 |
| 2026-08-16 12:00 |
15:07:04.98 |
-24:37:19.0 |
HIP 73932 |
14.67 |
| 2026-08-17 00:00 |
15:07:09.33 |
-24:37:18.0 |
HIP 73932 |
15.24 |
| 2026-08-17 12:00 |
15:07:13.79 |
-24:37:17.4 |
HIP 73932 |
15.87 |
| 2026-08-18 00:00 |
15:07:18.36 |
-24:37:17.4 |
HIP 73932 |
16.54 |
| 2026-08-18 12:00 |
15:07:23.04 |
-24:37:17.8 |
HIP 73932 |
17.26 |
| 2026-08-19 00:00 |
15:07:27.84 |
-24:37:18.7 |
HIP 73932 |
18.03 |