메타데이터
| 항목 |
값 |
| Designation |
C/2009 E1 (Itagaki) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2009-04-07T22:05:17.583360Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:29Z |
| Obs used |
562 |
| NEO |
- |
| M1 |
13.500 |
| K1 |
16.500 |
| PC |
0.030 |
Osculating 궤도요소
| 항목 |
값 |
| Epoch (epoch_cal, TDB) |
2009-04-29.0000000 |
| e |
0.98507270 |
| q (au) |
0.599722 |
| a (au) |
40.176157 |
| i (deg) |
127.453383 |
| Ω (om, deg) |
105.962011 |
| ω (w, deg) |
48.955232 |
| M (ma, deg) |
0.081586 |
밝기
산란 + 전체 선형
$$
M_a = (15.399 + 5.843\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
모델 상수
| 항목 |
값 |
| H0 |
15.399 |
| n |
5.843 |
| gf |
1.000 |
| gb |
-0.662 |
| k |
0.800 |
| 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 |
| 2008-03-20 |
2009-03-20 |
-20.1856 |
-2.656 |
| 2009-03-20 |
2009-04-06 |
+18.5283 |
+1.854 |
| 2009-04-08 |
2009-05-09 |
+5.8503 |
-2.134 |
| 2009-05-09 |
2009-05-27 |
-15.6180 |
-2.738 |
| 2009-05-27 |
2009-06-21 |
+20.5841 |
-3.922 |
| 2009-06-21 |
2009-07-04 |
+33.7442 |
-7.368 |
| 2009-07-04 |
2009-08-19 |
-24.8682 |
+6.863 |
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 |
17:21:28.45 |
-51:57:51.9 |
HIP 84967 |
8.30 |
| 2026-03-26 12:00 |
17:21:26.93 |
-51:58:17.9 |
HIP 84967 |
8.79 |
| 2026-03-27 00:00 |
17:21:25.37 |
-51:58:43.8 |
HIP 84967 |
9.28 |
| 2026-03-27 12:00 |
17:21:23.76 |
-51:59:09.6 |
HIP 84967 |
9.77 |
| 2026-03-28 00:00 |
17:21:22.10 |
-51:59:35.3 |
HIP 84967 |
10.27 |
| 2026-03-28 12:00 |
17:21:20.39 |
-52:00:00.9 |
HIP 84967 |
10.78 |
| 2026-03-29 00:00 |
17:21:18.62 |
-52:00:26.5 |
HIP 84967 |
11.28 |
| 2026-03-29 12:00 |
17:21:16.81 |
-52:00:52.0 |
HIP 84967 |
11.79 |
| 2026-03-30 00:00 |
17:21:14.95 |
-52:01:17.3 |
HIP 84802 |
12.02 |
| 2026-03-30 12:00 |
17:21:13.04 |
-52:01:42.6 |
HIP 84802 |
11.87 |
| 2026-03-31 00:00 |
17:21:11.09 |
-52:02:07.8 |
HIP 84802 |
11.72 |
| 2026-03-31 12:00 |
17:21:09.08 |
-52:02:33.0 |
HIP 84802 |
11.60 |
| 2026-04-01 00:00 |
17:21:07.02 |
-52:02:58.0 |
HIP 84802 |
11.48 |
| 2026-04-01 12:00 |
17:21:04.92 |
-52:03:22.9 |
HIP 84802 |
11.39 |
| 2026-04-02 00:00 |
17:21:02.77 |
-52:03:47.7 |
HIP 84802 |
11.31 |
| 2026-04-02 12:00 |
17:21:00.56 |
-52:04:12.4 |
HIP 84802 |
11.24 |
| 2026-04-03 00:00 |
17:20:58.32 |
-52:04:37.1 |
HIP 84802 |
11.20 |
| 2026-04-03 12:00 |
17:20:56.02 |
-52:05:01.6 |
HIP 84802 |
11.17 |
| 2026-04-04 00:00 |
17:20:53.67 |
-52:05:26.0 |
HIP 84802 |
11.16 |
| 2026-04-04 12:00 |
17:20:51.28 |
-52:05:50.3 |
HIP 84802 |
11.18 |
| 2026-04-05 00:00 |
17:20:48.83 |
-52:06:14.5 |
HIP 84802 |
11.21 |
| 2026-04-05 12:00 |
17:20:46.34 |
-52:06:38.6 |
HIP 84802 |
11.27 |
| 2026-04-06 00:00 |
17:20:43.81 |
-52:07:02.6 |
HIP 84802 |
11.34 |
| 2026-04-06 12:00 |
17:20:41.22 |
-52:07:26.4 |
HIP 84802 |
11.44 |
| 2026-04-07 00:00 |
17:20:38.59 |
-52:07:50.1 |
HIP 84802 |
11.56 |
| 2026-04-07 12:00 |
17:20:35.91 |
-52:08:13.8 |
HIP 84802 |
11.70 |
| 2026-04-08 00:00 |
17:20:33.18 |
-52:08:37.3 |
HIP 84802 |
11.86 |
| 2026-04-08 12:00 |
17:20:30.41 |
-52:09:00.6 |
HIP 84802 |
12.04 |
| 2026-04-09 00:00 |
17:20:27.59 |
-52:09:23.9 |
HIP 84802 |
12.24 |
| 2026-04-09 12:00 |
17:20:24.72 |
-52:09:47.0 |
HIP 84802 |
12.46 |
| 2026-04-10 00:00 |
17:20:21.81 |
-52:10:10.0 |
HIP 84802 |
12.70 |
| 2026-04-10 12:00 |
17:20:18.85 |
-52:10:32.9 |
HIP 84802 |
12.96 |
| 2026-04-11 00:00 |
17:20:15.85 |
-52:10:55.6 |
HIP 84802 |
13.23 |
| 2026-04-11 12:00 |
17:20:12.80 |
-52:11:18.2 |
HIP 84802 |
13.53 |
| 2026-04-12 00:00 |
17:20:09.70 |
-52:11:40.7 |
HIP 84802 |
13.84 |
| 2026-04-12 12:00 |
17:20:06.56 |
-52:12:03.0 |
HIP 84802 |
14.17 |
| 2026-04-13 00:00 |
17:20:03.37 |
-52:12:25.2 |
HIP 84802 |
14.51 |
| 2026-04-13 12:00 |
17:20:00.14 |
-52:12:47.2 |
HIP 84802 |
14.87 |
| 2026-04-14 00:00 |
17:19:56.86 |
-52:13:09.1 |
HIP 84802 |
15.24 |
| 2026-04-14 12:00 |
17:19:53.54 |
-52:13:30.9 |
HIP 84802 |
15.63 |
| 2026-04-15 00:00 |
17:19:50.17 |
-52:13:52.5 |
HIP 84802 |
16.03 |
| 2026-04-15 12:00 |
17:19:46.76 |
-52:14:14.0 |
HIP 84802 |
16.44 |
| 2026-04-16 00:00 |
17:19:43.30 |
-52:14:35.3 |
HIP 84802 |
16.86 |