メタデータ
| 項目 |
値 |
| Designation |
261P/Larson |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2019-06-17T02:43:12.308160Z |
| Orbit solution date (soln_date, UTC) |
2026-09-04T08:42:17Z |
| Obs used |
1339 |
| NEO |
- |
| M1 |
5.600 |
| K1 |
32.750 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2016-10-10.0000000 |
| e |
0.41868920 |
| q (au) |
2.048706 |
| a (au) |
3.524287 |
| i (deg) |
6.050057 |
| Ω (om, deg) |
294.226531 |
| ω (w, deg) |
62.728994 |
| M (ma, deg) |
213.993083 |
等級
散乱 + 全体線形
$$
M_a = (10.802 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.802 |
| 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 |
2026-02-13 |
+27.6125 |
-9.326 |
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) |
| 2026-09-20 00:00 |
07:05:36.38 |
+25:09:48.8 |
HIP 34266 |
19.87 |
| 2026-09-20 12:00 |
07:06:10.51 |
+25:08:42.1 |
HIP 34266 |
17.09 |
| 2026-09-21 00:00 |
07:06:44.38 |
+25:07:35.4 |
HIP 34266 |
17.62 |
| 2026-09-21 12:00 |
07:07:18.00 |
+25:06:28.6 |
HIP 34266 |
21.15 |
| 2026-09-22 00:00 |
07:07:51.37 |
+25:05:21.7 |
HIP 34532 |
22.42 |
| 2026-09-22 12:00 |
07:08:24.48 |
+25:04:14.7 |
HIP 34532 |
16.88 |
| 2026-09-23 00:00 |
07:08:57.34 |
+25:03:07.7 |
HIP 34532 |
13.53 |
| 2026-09-23 12:00 |
07:09:29.94 |
+25:02:00.7 |
HIP 34532 |
13.92 |
| 2026-09-24 00:00 |
07:10:02.28 |
+25:00:53.7 |
HIP 34532 |
17.74 |
| 2026-09-24 12:00 |
07:10:34.37 |
+24:59:46.6 |
HIP 34704 |
22.01 |
| 2026-09-25 00:00 |
07:11:06.19 |
+24:58:39.6 |
HIP 34704 |
18.95 |
| 2026-09-25 12:00 |
07:11:37.75 |
+24:57:32.6 |
HIP 34704 |
18.43 |
| 2026-09-26 00:00 |
07:12:09.04 |
+24:56:25.5 |
HIP 34704 |
20.59 |
| 2026-09-26 12:00 |
07:12:40.07 |
+24:55:18.6 |
HIP 34950 |
17.46 |
| 2026-09-27 00:00 |
07:13:10.83 |
+24:54:11.6 |
HIP 34950 |
11.63 |
| 2026-09-27 12:00 |
07:13:41.33 |
+24:53:04.7 |
HIP 34950 |
8.09 |
| 2026-09-28 00:00 |
07:14:11.56 |
+24:51:57.9 |
HIP 35025 |
6.99 |
| 2026-09-28 12:00 |
07:14:41.51 |
+24:50:51.2 |
HIP 35025 |
2.26 |
| 2026-09-29 00:00 |
07:15:11.19 |
+24:49:44.5 |
HIP 35025 |
7.44 |
| 2026-09-29 12:00 |
07:15:40.60 |
+24:48:38.0 |
HIP 35025 |
14.04 |
| 2026-09-30 00:00 |
07:16:09.74 |
+24:47:31.5 |
HIP 35222 |
17.45 |
| 2026-09-30 12:00 |
07:16:38.59 |
+24:46:25.2 |
HIP 35222 |
14.19 |
| 2026-10-01 00:00 |
07:17:07.17 |
+24:45:19.0 |
HIP 35222 |
13.64 |
| 2026-10-01 12:00 |
07:17:35.47 |
+24:44:13.0 |
HIP 35324 |
12.80 |
| 2026-10-02 00:00 |
07:18:03.48 |
+24:43:07.1 |
HIP 35324 |
12.05 |
| 2026-10-02 12:00 |
07:18:31.22 |
+24:42:01.3 |
HIP 35324 |
14.45 |
| 2026-10-03 00:00 |
07:18:58.66 |
+24:40:55.8 |
HIP 35324 |
18.76 |
| 2026-10-03 12:00 |
07:19:25.82 |
+24:39:50.4 |
HIP 35324 |
23.93 |
| 2026-10-04 00:00 |
07:19:52.69 |
+24:38:45.3 |
HIP 35617 |
26.01 |
| 2026-10-04 12:00 |
07:20:19.26 |
+24:37:40.4 |
HIP 35617 |
24.05 |
| 2026-10-05 00:00 |
07:20:45.54 |
+24:36:35.6 |
HIP 35617 |
23.57 |
| 2026-10-05 12:00 |
07:21:11.53 |
+24:35:31.2 |
HIP 35617 |
24.61 |
| 2026-10-06 00:00 |
07:21:37.22 |
+24:34:26.9 |
HIP 35820 |
25.57 |
| 2026-10-06 12:00 |
07:22:02.61 |
+24:33:23.0 |
HIP 35820 |
20.12 |
| 2026-10-07 00:00 |
07:22:27.70 |
+24:32:19.3 |
HIP 35820 |
15.05 |
| 2026-10-07 12:00 |
07:22:52.49 |
+24:31:15.9 |
HIP 35820 |
10.79 |
| 2026-10-08 00:00 |
07:23:16.98 |
+24:30:12.8 |
HIP 35820 |
8.50 |
| 2026-10-08 12:00 |
07:23:41.15 |
+24:29:09.9 |
HIP 35820 |
9.57 |
| 2026-10-09 00:00 |
07:24:05.02 |
+24:28:07.5 |
HIP 35820 |
13.12 |
| 2026-10-09 12:00 |
07:24:28.58 |
+24:27:05.3 |
HIP 35820 |
17.65 |
| 2026-10-10 00:00 |
07:24:51.83 |
+24:26:03.5 |
HIP 35820 |
22.53 |
| 2026-10-10 12:00 |
07:25:14.77 |
+24:25:02.0 |
HIP 35820 |
27.53 |
| 2026-10-11 00:00 |
07:25:37.39 |
+24:24:00.9 |
HIP 36180 |
24.64 |