メタデータ
| 項目 |
値 |
| Designation |
66P/du Toit |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2018-05-20T11:15:17.081280Z |
| Orbit solution date (soln_date, UTC) |
2019-06-03T14:53:20Z |
| Obs used |
547 |
| NEO |
Yes |
| M1 |
15.700 |
| K1 |
7.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2014-10-31.0000000 |
| e |
0.78656817 |
| q (au) |
1.285451 |
| a (au) |
6.022773 |
| i (deg) |
18.668971 |
| Ω (om, deg) |
21.999851 |
| ω (w, deg) |
257.342734 |
| M (ma, deg) |
273.482032 |
等級
散乱 + 全体線形
$$
M_a = (13.128 + 5.614\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
13.128 |
| n |
5.614 |
| gf |
0.972 |
| gb |
-0.780 |
| k |
0.995 |
| δ90 |
9.986 |
| パラメータ |
記号 |
範囲 |
説明 |
| 太陽・地球距離が1 AUのときの絶対等級 |
H0 |
-5 to 20 |
彗星の固有の明るさ |
| 測光スロープパラメータ |
n |
2 to 6 |
太陽距離に対する明るさ変化率 |
| 前方散乱非対称係数 |
gf |
0.8 to 1 |
前方散乱の強さ |
| 後方散乱非対称係数 |
gb |
-1 to -0.5 |
後方散乱の強さ |
| 分配係数 |
k |
0.8 to 1 |
前方/後方散乱の寄与比 |
| ダスト/ガス明るさ比 |
δ90 |
1 to 10 |
ダスト散乱とガス放射の相対寄与 |
参考: EPSC-DPS2025-160
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2018-01-14 |
2018-05-20 |
+20.2696 |
-4.971 |
| 2018-05-21 |
2018-10-04 |
+19.3494 |
-5.821 |
| 2018-10-04 |
2018-11-10 |
-27.9509 |
+9.461 |
log10 r = log10(太陽距離/AU)、Δ = 地球距離(AU)
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
06:35:23.75 |
+40:30:06.3 |
HIP 31304 |
17.86 |
| 2026-05-12 12:00 |
06:35:34.67 |
+40:29:26.7 |
HIP 31304 |
20.04 |
| 2026-05-13 00:00 |
06:35:45.67 |
+40:28:47.4 |
HIP 31304 |
22.22 |
| 2026-05-13 12:00 |
06:35:56.73 |
+40:28:08.2 |
HIP 31657 |
21.14 |
| 2026-05-14 00:00 |
06:36:07.87 |
+40:27:29.2 |
HIP 31657 |
19.73 |
| 2026-05-14 12:00 |
06:36:19.07 |
+40:26:50.4 |
HIP 31657 |
18.47 |
| 2026-05-15 00:00 |
06:36:30.33 |
+40:26:11.8 |
HIP 31657 |
17.38 |
| 2026-05-15 12:00 |
06:36:41.67 |
+40:25:33.4 |
HIP 31657 |
16.52 |
| 2026-05-16 00:00 |
06:36:53.06 |
+40:24:55.2 |
HIP 31657 |
15.93 |
| 2026-05-16 12:00 |
06:37:04.53 |
+40:24:17.1 |
HIP 31657 |
15.63 |
| 2026-05-17 00:00 |
06:37:16.06 |
+40:23:39.3 |
HIP 31657 |
15.65 |
| 2026-05-17 12:00 |
06:37:27.65 |
+40:23:01.6 |
HIP 31657 |
16.00 |
| 2026-05-18 00:00 |
06:37:39.30 |
+40:22:24.1 |
HIP 31657 |
16.66 |
| 2026-05-18 12:00 |
06:37:51.02 |
+40:21:46.8 |
HIP 31657 |
17.59 |
| 2026-05-19 00:00 |
06:38:02.79 |
+40:21:09.7 |
HIP 31657 |
18.76 |
| 2026-05-19 12:00 |
06:38:14.63 |
+40:20:32.8 |
HIP 31657 |
20.14 |
| 2026-05-20 00:00 |
06:38:26.53 |
+40:19:56.1 |
HIP 31657 |
21.69 |
| 2026-05-20 12:00 |
06:38:38.48 |
+40:19:19.6 |
HIP 31657 |
23.37 |
| 2026-05-21 00:00 |
06:38:50.50 |
+40:18:43.3 |
HIP 31956 |
23.05 |
| 2026-05-21 12:00 |
06:39:02.57 |
+40:18:07.2 |
HIP 31956 |
20.69 |
| 2026-05-22 00:00 |
06:39:14.70 |
+40:17:31.3 |
HIP 31956 |
18.33 |
| 2026-05-22 12:00 |
06:39:26.88 |
+40:16:55.6 |
HIP 31956 |
15.97 |
| 2026-05-23 00:00 |
06:39:39.12 |
+40:16:20.1 |
HIP 31956 |
13.61 |
| 2026-05-23 12:00 |
06:39:51.41 |
+40:15:44.7 |
HIP 31956 |
11.27 |
| 2026-05-24 00:00 |
06:40:03.76 |
+40:15:09.6 |
HIP 31956 |
8.96 |
| 2026-05-24 12:00 |
06:40:16.16 |
+40:14:34.7 |
HIP 31956 |
6.73 |
| 2026-05-25 00:00 |
06:40:28.62 |
+40:14:00.0 |
HIP 31956 |
4.71 |
| 2026-05-25 12:00 |
06:40:41.12 |
+40:13:25.4 |
HIP 31956 |
3.32 |
| 2026-05-26 00:00 |
06:40:53.68 |
+40:12:51.1 |
HIP 31956 |
3.47 |
| 2026-05-26 12:00 |
06:41:06.29 |
+40:12:17.0 |
HIP 31956 |
5.03 |
| 2026-05-27 00:00 |
06:41:18.95 |
+40:11:43.1 |
HIP 31956 |
7.14 |
| 2026-05-27 12:00 |
06:41:31.65 |
+40:11:09.4 |
HIP 31956 |
9.44 |
| 2026-05-28 00:00 |
06:41:44.41 |
+40:10:35.8 |
HIP 31964 |
11.58 |
| 2026-05-28 12:00 |
06:41:57.21 |
+40:10:02.5 |
HIP 31964 |
13.74 |
| 2026-05-29 00:00 |
06:42:10.06 |
+40:09:29.4 |
HIP 32132 |
15.20 |
| 2026-05-29 12:00 |
06:42:22.96 |
+40:08:56.5 |
HIP 32132 |
14.00 |
| 2026-05-30 00:00 |
06:42:35.90 |
+40:08:23.8 |
HIP 32132 |
13.18 |
| 2026-05-30 12:00 |
06:42:48.89 |
+40:07:51.3 |
HIP 32211 |
12.30 |
| 2026-05-31 00:00 |
06:43:01.93 |
+40:07:19.0 |
HIP 32211 |
10.61 |
| 2026-05-31 12:00 |
06:43:15.01 |
+40:06:46.9 |
HIP 32211 |
9.32 |
| 2026-06-01 00:00 |
06:43:28.13 |
+40:06:15.0 |
HIP 32211 |
8.63 |
| 2026-06-01 12:00 |
06:43:41.29 |
+40:05:43.3 |
HIP 32211 |
8.67 |
| 2026-06-02 00:00 |
06:43:54.50 |
+40:05:11.9 |
HIP 32211 |
9.45 |