メタデータ
| 項目 |
値 |
| Designation |
261P/Larson |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2019-06-17T05:55:39.953280Z |
| Orbit solution date (soln_date, UTC) |
2026-03-31T09:42:39Z |
| Obs used |
1333 |
| NEO |
- |
| M1 |
5.800 |
| K1 |
32.250 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2016-09-27.0000000 |
| e |
0.41834775 |
| q (au) |
2.050551 |
| a (au) |
3.525389 |
| i (deg) |
6.053412 |
| Ω (om, deg) |
294.373787 |
| ω (w, deg) |
62.549411 |
| M (ma, deg) |
212.105953 |
等級
散乱 + 全体線形
$$
M_a = (10.843 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.843 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
10.000 |
| 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 |
| 2025-05-25 |
2026-01-05 |
+24.5971 |
-8.320 |
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 |
03:06:57.63 |
+21:21:00.5 |
HIP 14481 |
29.31 |
| 2026-05-12 12:00 |
03:08:02.69 |
+21:24:59.3 |
HIP 14727 |
31.90 |
| 2026-05-13 00:00 |
03:09:07.73 |
+21:28:56.6 |
HIP 14727 |
20.03 |
| 2026-05-13 12:00 |
03:10:12.76 |
+21:32:52.2 |
HIP 14715 |
12.05 |
| 2026-05-14 00:00 |
03:11:17.76 |
+21:36:46.3 |
HIP 14715 |
18.41 |
| 2026-05-14 12:00 |
03:12:22.75 |
+21:40:38.8 |
HIP 14993 |
12.27 |
| 2026-05-15 00:00 |
03:13:27.72 |
+21:44:29.8 |
HIP 14993 |
6.53 |
| 2026-05-15 12:00 |
03:14:32.66 |
+21:48:19.1 |
HIP 14993 |
20.47 |
| 2026-05-16 00:00 |
03:15:37.59 |
+21:52:06.8 |
HIP 15038 |
33.91 |
| 2026-05-16 12:00 |
03:16:42.49 |
+21:55:52.9 |
HIP 15038 |
44.32 |
| 2026-05-17 00:00 |
03:17:47.37 |
+21:59:37.5 |
HIP 15513 |
41.32 |
| 2026-05-17 12:00 |
03:18:52.23 |
+22:03:20.4 |
HIP 15562 |
31.11 |
| 2026-05-18 00:00 |
03:19:57.06 |
+22:07:01.7 |
HIP 15562 |
19.38 |
| 2026-05-18 12:00 |
03:21:01.87 |
+22:10:41.4 |
HIP 15562 |
16.17 |
| 2026-05-19 00:00 |
03:22:06.65 |
+22:14:19.5 |
HIP 15562 |
24.97 |
| 2026-05-19 12:00 |
03:23:11.40 |
+22:17:56.0 |
HIP 15908 |
23.23 |
| 2026-05-20 00:00 |
03:24:16.13 |
+22:21:30.8 |
HIP 15908 |
9.53 |
| 2026-05-20 12:00 |
03:25:20.83 |
+22:25:04.0 |
HIP 15908 |
10.75 |
| 2026-05-21 00:00 |
03:26:25.50 |
+22:28:35.6 |
HIP 15908 |
24.74 |
| 2026-05-21 12:00 |
03:27:30.14 |
+22:32:05.6 |
HIP 16181 |
20.75 |
| 2026-05-22 00:00 |
03:28:34.75 |
+22:35:33.9 |
HIP 16181 |
12.83 |
| 2026-05-22 12:00 |
03:29:39.34 |
+22:39:00.7 |
HIP 16181 |
19.16 |
| 2026-05-23 00:00 |
03:30:43.89 |
+22:42:25.7 |
HIP 16428 |
16.28 |
| 2026-05-23 12:00 |
03:31:48.40 |
+22:45:49.2 |
HIP 16428 |
15.97 |
| 2026-05-24 00:00 |
03:32:52.89 |
+22:49:11.0 |
HIP 16668 |
22.74 |
| 2026-05-24 12:00 |
03:33:57.34 |
+22:52:31.2 |
HIP 16668 |
10.29 |
| 2026-05-25 00:00 |
03:35:01.76 |
+22:55:49.7 |
HIP 16753 |
9.41 |
| 2026-05-25 12:00 |
03:36:06.15 |
+22:59:06.6 |
HIP 16753 |
12.52 |
| 2026-05-26 00:00 |
03:37:10.50 |
+23:02:21.8 |
HIP 16859 |
10.69 |
| 2026-05-26 12:00 |
03:38:14.82 |
+23:05:35.5 |
HIP 16859 |
19.02 |
| 2026-05-27 00:00 |
03:39:19.10 |
+23:08:47.5 |
HIP 17091 |
10.04 |
| 2026-05-27 12:00 |
03:40:23.35 |
+23:11:57.8 |
HIP 17091 |
11.14 |
| 2026-05-28 00:00 |
03:41:27.56 |
+23:15:06.5 |
HIP 17225 |
14.15 |
| 2026-05-28 12:00 |
03:42:31.73 |
+23:18:13.6 |
HIP 17225 |
19.23 |
| 2026-05-29 00:00 |
03:43:35.87 |
+23:21:19.0 |
HIP 17401 |
17.69 |
| 2026-05-29 12:00 |
03:44:39.97 |
+23:24:22.8 |
HIP 17497 |
8.63 |
| 2026-05-30 00:00 |
03:45:44.03 |
+23:27:24.9 |
HIP 17497 |
16.55 |
| 2026-05-30 12:00 |
03:46:48.05 |
+23:30:25.4 |
HIP 17684 |
14.78 |
| 2026-05-31 00:00 |
03:47:52.03 |
+23:33:24.3 |
HIP 17776 |
10.46 |
| 2026-05-31 12:00 |
03:48:55.97 |
+23:36:21.5 |
HIP 17900 |
12.61 |
| 2026-06-01 00:00 |
03:49:59.88 |
+23:39:17.1 |
HIP 17900 |
5.08 |
| 2026-06-01 12:00 |
03:51:03.74 |
+23:42:11.0 |
HIP 18018 |
12.04 |
| 2026-06-02 00:00 |
03:52:07.56 |
+23:45:03.4 |
HIP 18018 |
17.38 |