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) |
| 2026-05-12 00:00 |
17:15:50.63 |
-52:28:53.5 |
HIP 84456 |
10.50 |
| 2026-05-12 12:00 |
17:15:45.29 |
-52:29:04.5 |
HIP 84456 |
10.81 |
| 2026-05-13 00:00 |
17:15:39.93 |
-52:29:15.3 |
HIP 84456 |
11.17 |
| 2026-05-13 12:00 |
17:15:34.55 |
-52:29:25.9 |
HIP 84456 |
11.58 |
| 2026-05-14 00:00 |
17:15:29.14 |
-52:29:36.2 |
HIP 84456 |
12.03 |
| 2026-05-14 12:00 |
17:15:23.71 |
-52:29:46.4 |
HIP 84365 |
12.38 |
| 2026-05-15 00:00 |
17:15:18.25 |
-52:29:56.2 |
HIP 84365 |
12.24 |
| 2026-05-15 12:00 |
17:15:12.77 |
-52:30:05.9 |
HIP 84365 |
12.14 |
| 2026-05-16 00:00 |
17:15:07.26 |
-52:30:15.3 |
HIP 84365 |
12.10 |
| 2026-05-16 12:00 |
17:15:01.73 |
-52:30:24.5 |
HIP 84365 |
12.11 |
| 2026-05-17 00:00 |
17:14:56.18 |
-52:30:33.4 |
HIP 84365 |
12.19 |
| 2026-05-17 12:00 |
17:14:50.61 |
-52:30:42.2 |
HIP 84365 |
12.31 |
| 2026-05-18 00:00 |
17:14:45.02 |
-52:30:50.6 |
HIP 84365 |
12.49 |
| 2026-05-18 12:00 |
17:14:39.40 |
-52:30:58.9 |
HIP 84365 |
12.73 |
| 2026-05-19 00:00 |
17:14:33.77 |
-52:31:06.9 |
HIP 84365 |
13.01 |
| 2026-05-19 12:00 |
17:14:28.11 |
-52:31:14.6 |
HIP 84365 |
13.35 |
| 2026-05-20 00:00 |
17:14:22.44 |
-52:31:22.1 |
HIP 84365 |
13.72 |
| 2026-05-20 12:00 |
17:14:16.75 |
-52:31:29.4 |
HIP 84365 |
14.14 |
| 2026-05-21 00:00 |
17:14:11.04 |
-52:31:36.4 |
HIP 84365 |
14.60 |
| 2026-05-21 12:00 |
17:14:05.31 |
-52:31:43.2 |
HIP 84365 |
15.09 |
| 2026-05-22 00:00 |
17:13:59.56 |
-52:31:49.8 |
HIP 84365 |
15.61 |
| 2026-05-22 12:00 |
17:13:53.80 |
-52:31:56.1 |
HIP 84365 |
16.17 |
| 2026-05-23 00:00 |
17:13:48.02 |
-52:32:02.1 |
HIP 84365 |
16.75 |
| 2026-05-23 12:00 |
17:13:42.22 |
-52:32:07.9 |
HIP 84365 |
17.35 |
| 2026-05-24 00:00 |
17:13:36.41 |
-52:32:13.5 |
HIP 84365 |
17.98 |
| 2026-05-24 12:00 |
17:13:30.59 |
-52:32:18.8 |
HIP 84365 |
18.62 |
| 2026-05-25 00:00 |
17:13:24.74 |
-52:32:23.9 |
HIP 84085 |
18.66 |
| 2026-05-25 12:00 |
17:13:18.89 |
-52:32:28.8 |
HIP 84085 |
17.82 |
| 2026-05-26 00:00 |
17:13:13.02 |
-52:32:33.4 |
HIP 84085 |
16.97 |
| 2026-05-26 12:00 |
17:13:07.14 |
-52:32:37.7 |
HIP 84085 |
16.13 |
| 2026-05-27 00:00 |
17:13:01.24 |
-52:32:41.8 |
HIP 84085 |
15.29 |
| 2026-05-27 12:00 |
17:12:55.34 |
-52:32:45.7 |
HIP 84085 |
14.45 |
| 2026-05-28 00:00 |
17:12:49.42 |
-52:32:49.3 |
HIP 84085 |
13.62 |
| 2026-05-28 12:00 |
17:12:43.49 |
-52:32:52.6 |
HIP 84085 |
12.79 |
| 2026-05-29 00:00 |
17:12:37.55 |
-52:32:55.8 |
HIP 84085 |
11.98 |
| 2026-05-29 12:00 |
17:12:31.60 |
-52:32:58.6 |
HIP 84085 |
11.17 |
| 2026-05-30 00:00 |
17:12:25.64 |
-52:33:01.2 |
HIP 84085 |
10.38 |
| 2026-05-30 12:00 |
17:12:19.66 |
-52:33:03.6 |
HIP 84085 |
9.61 |
| 2026-05-31 00:00 |
17:12:13.68 |
-52:33:05.7 |
HIP 84085 |
8.85 |
| 2026-05-31 12:00 |
17:12:07.70 |
-52:33:07.6 |
HIP 84085 |
8.13 |
| 2026-06-01 00:00 |
17:12:01.70 |
-52:33:09.3 |
HIP 84085 |
7.44 |
| 2026-06-01 12:00 |
17:11:55.69 |
-52:33:10.7 |
HIP 84085 |
6.81 |
| 2026-06-02 00:00 |
17:11:49.68 |
-52:33:11.8 |
HIP 84085 |
6.24 |