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 |
0.999 |
| 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 |
-20.1855 |
-2.656 |
| 2009-03-20 |
2009-04-06 |
+18.5279 |
+1.854 |
| 2009-04-08 |
2009-05-09 |
+5.8500 |
-2.134 |
| 2009-05-09 |
2009-05-27 |
-15.6182 |
-2.738 |
| 2009-05-27 |
2009-06-21 |
+20.5841 |
-3.922 |
| 2009-06-21 |
2009-07-04 |
+33.7456 |
-7.368 |
| 2009-07-04 |
2009-08-19 |
-24.8681 |
+6.863 |
log10 r = log10(태양거리/AU), Δ = 지구거리(AU)
천체력
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
17:01:33.52 |
-52:10:49.6 |
HIP 83220 |
11.46 |
| 2026-07-29 12:00 |
17:01:29.65 |
-52:10:27.7 |
HIP 83220 |
11.14 |
| 2026-07-30 00:00 |
17:01:25.82 |
-52:10:05.6 |
HIP 83220 |
10.86 |
| 2026-07-30 12:00 |
17:01:22.03 |
-52:09:43.3 |
HIP 83220 |
10.62 |
| 2026-07-31 00:00 |
17:01:18.28 |
-52:09:21.0 |
HIP 83220 |
10.43 |
| 2026-07-31 12:00 |
17:01:14.57 |
-52:08:58.6 |
HIP 83220 |
10.29 |
| 2026-08-01 00:00 |
17:01:10.90 |
-52:08:36.1 |
HIP 83220 |
10.20 |
| 2026-08-01 12:00 |
17:01:07.28 |
-52:08:13.4 |
HIP 83220 |
10.16 |
| 2026-08-02 00:00 |
17:01:03.69 |
-52:07:50.7 |
HIP 83220 |
10.16 |
| 2026-08-02 12:00 |
17:01:00.14 |
-52:07:27.9 |
HIP 83220 |
10.21 |
| 2026-08-03 00:00 |
17:00:56.64 |
-52:07:04.9 |
HIP 83220 |
10.31 |
| 2026-08-03 12:00 |
17:00:53.18 |
-52:06:41.9 |
HIP 83220 |
10.46 |
| 2026-08-04 00:00 |
17:00:49.76 |
-52:06:18.8 |
HIP 83220 |
10.64 |
| 2026-08-04 12:00 |
17:00:46.38 |
-52:05:55.6 |
HIP 83220 |
10.87 |
| 2026-08-05 00:00 |
17:00:43.04 |
-52:05:32.3 |
HIP 83220 |
11.13 |
| 2026-08-05 12:00 |
17:00:39.75 |
-52:05:08.9 |
HIP 83220 |
11.42 |
| 2026-08-06 00:00 |
17:00:36.50 |
-52:04:45.4 |
HIP 83220 |
11.75 |
| 2026-08-06 12:00 |
17:00:33.30 |
-52:04:21.9 |
HIP 83220 |
12.10 |
| 2026-08-07 00:00 |
17:00:30.13 |
-52:03:58.2 |
HIP 83220 |
12.47 |
| 2026-08-07 12:00 |
17:00:27.01 |
-52:03:34.5 |
HIP 83220 |
12.86 |
| 2026-08-08 00:00 |
17:00:23.94 |
-52:03:10.7 |
HIP 83220 |
13.27 |
| 2026-08-08 12:00 |
17:00:20.91 |
-52:02:46.9 |
HIP 83220 |
13.70 |
| 2026-08-09 00:00 |
17:00:17.92 |
-52:02:22.9 |
HIP 83220 |
14.14 |
| 2026-08-09 12:00 |
17:00:14.97 |
-52:01:58.9 |
HIP 83220 |
14.60 |
| 2026-08-10 00:00 |
17:00:12.08 |
-52:01:34.9 |
HIP 83220 |
15.06 |
| 2026-08-10 12:00 |
17:00:09.22 |
-52:01:10.7 |
HIP 83220 |
15.54 |
| 2026-08-11 00:00 |
17:00:06.41 |
-52:00:46.5 |
HIP 83220 |
16.02 |
| 2026-08-11 12:00 |
17:00:03.65 |
-52:00:22.2 |
HIP 83220 |
16.50 |
| 2026-08-12 00:00 |
17:00:00.93 |
-51:59:57.9 |
HIP 83220 |
17.00 |
| 2026-08-12 12:00 |
16:59:58.26 |
-51:59:33.5 |
HIP 83220 |
17.49 |
| 2026-08-13 00:00 |
16:59:55.63 |
-51:59:09.1 |
HIP 83220 |
18.00 |
| 2026-08-13 12:00 |
16:59:53.05 |
-51:58:44.6 |
HIP 83220 |
18.50 |
| 2026-08-14 00:00 |
16:59:50.52 |
-51:58:20.0 |
HIP 83220 |
19.01 |
| 2026-08-14 12:00 |
16:59:48.03 |
-51:57:55.4 |
HIP 83220 |
19.52 |
| 2026-08-15 00:00 |
16:59:45.59 |
-51:57:30.8 |
HIP 83220 |
20.03 |
| 2026-08-15 12:00 |
16:59:43.19 |
-51:57:06.1 |
HIP 83220 |
20.54 |
| 2026-08-16 00:00 |
16:59:40.84 |
-51:56:41.4 |
HIP 83220 |
21.05 |
| 2026-08-16 12:00 |
16:59:38.54 |
-51:56:16.6 |
HIP 82976 |
21.20 |
| 2026-08-17 00:00 |
16:59:36.29 |
-51:55:51.8 |
HIP 82976 |
20.80 |
| 2026-08-17 12:00 |
16:59:34.08 |
-51:55:27.0 |
HIP 82976 |
20.42 |
| 2026-08-18 00:00 |
16:59:31.92 |
-51:55:02.1 |
HIP 82976 |
20.05 |
| 2026-08-18 12:00 |
16:59:29.80 |
-51:54:37.2 |
HIP 82976 |
19.69 |
| 2026-08-19 00:00 |
16:59:27.74 |
-51:54:12.3 |
HIP 82976 |
19.35 |