メタデータ
| 項目 |
値 |
| Designation |
327P/Van Ness |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2022-09-02T13:33:36.086400Z |
| Orbit solution date (soln_date, UTC) |
2024-06-21T13:42:21Z |
| Obs used |
900 |
| NEO |
- |
| M1 |
14.800 |
| K1 |
11.500 |
| PC |
0.030 |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2020-09-26.0000000 |
| e |
0.56283038 |
| q (au) |
1.557541 |
| a (au) |
3.562783 |
| i (deg) |
36.245156 |
| Ω (om, deg) |
173.974419 |
| ω (w, deg) |
185.022025 |
| M (ma, deg) |
256.444765 |
等級
散乱 + 全体線形
$$
M_a = (14.825 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
14.825 |
| n |
6.000 |
| gf |
0.995 |
| gb |
-0.647 |
| k |
0.800 |
| δ90 |
2.043 |
| 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 |
| 2020-05-30 |
2022-09-02 |
-11.8557 |
+2.478 |
| 2022-09-03 |
2023-01-20 |
-0.5923 |
+0.111 |
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) |
| 2026-07-29 00:00 |
12:04:08.70 |
+08:14:32.8 |
HIP 58715 |
25.38 |
| 2026-07-29 12:00 |
12:04:24.28 |
+08:13:11.3 |
HIP 58715 |
28.49 |
| 2026-07-30 00:00 |
12:04:39.96 |
+08:11:49.3 |
HIP 58715 |
31.84 |
| 2026-07-30 12:00 |
12:04:55.73 |
+08:10:26.9 |
HIP 58948 |
33.78 |
| 2026-07-31 00:00 |
12:05:11.59 |
+08:09:04.0 |
HIP 58948 |
34.91 |
| 2026-07-31 12:00 |
12:05:27.55 |
+08:07:40.7 |
HIP 58948 |
36.48 |
| 2026-08-01 00:00 |
12:05:43.59 |
+08:06:16.9 |
HIP 59144 |
38.14 |
| 2026-08-01 12:00 |
12:05:59.71 |
+08:04:52.8 |
HIP 59144 |
36.25 |
| 2026-08-02 00:00 |
12:06:15.93 |
+08:03:28.2 |
HIP 59057 |
34.02 |
| 2026-08-02 12:00 |
12:06:32.24 |
+08:02:03.1 |
HIP 59057 |
32.15 |
| 2026-08-03 00:00 |
12:06:48.63 |
+08:00:37.7 |
HIP 59057 |
30.76 |
| 2026-08-03 12:00 |
12:07:05.10 |
+07:59:11.9 |
HIP 59057 |
29.92 |
| 2026-08-04 00:00 |
12:07:21.67 |
+07:57:45.6 |
HIP 59057 |
29.70 |
| 2026-08-04 12:00 |
12:07:38.32 |
+07:56:19.0 |
HIP 59057 |
30.12 |
| 2026-08-05 00:00 |
12:07:55.05 |
+07:54:51.9 |
HIP 59057 |
31.16 |
| 2026-08-05 12:00 |
12:08:11.87 |
+07:53:24.5 |
HIP 59289 |
29.10 |
| 2026-08-06 00:00 |
12:08:28.77 |
+07:51:56.7 |
HIP 59289 |
26.86 |
| 2026-08-06 12:00 |
12:08:45.75 |
+07:50:28.5 |
HIP 59289 |
25.21 |
| 2026-08-07 00:00 |
12:09:02.82 |
+07:49:00.0 |
HIP 59289 |
24.26 |
| 2026-08-07 12:00 |
12:09:19.96 |
+07:47:31.1 |
HIP 59289 |
24.12 |
| 2026-08-08 00:00 |
12:09:37.19 |
+07:46:01.8 |
HIP 59289 |
24.82 |
| 2026-08-08 12:00 |
12:09:54.50 |
+07:44:32.1 |
HIP 59289 |
26.29 |
| 2026-08-09 00:00 |
12:10:11.89 |
+07:43:02.1 |
HIP 59289 |
28.42 |
| 2026-08-09 12:00 |
12:10:29.36 |
+07:41:31.8 |
HIP 59438 |
24.73 |
| 2026-08-10 00:00 |
12:10:46.90 |
+07:40:01.2 |
HIP 59438 |
20.99 |
| 2026-08-10 12:00 |
12:11:04.53 |
+07:38:30.2 |
HIP 59438 |
17.66 |
| 2026-08-11 00:00 |
12:11:22.23 |
+07:36:58.8 |
HIP 59438 |
15.01 |
| 2026-08-11 12:00 |
12:11:40.01 |
+07:35:27.2 |
HIP 59438 |
13.48 |
| 2026-08-12 00:00 |
12:11:57.86 |
+07:33:55.2 |
HIP 59438 |
13.49 |
| 2026-08-12 12:00 |
12:12:15.80 |
+07:32:23.0 |
HIP 59438 |
15.05 |
| 2026-08-13 00:00 |
12:12:33.80 |
+07:30:50.4 |
HIP 59438 |
17.76 |
| 2026-08-13 12:00 |
12:12:51.88 |
+07:29:17.6 |
HIP 59438 |
21.21 |
| 2026-08-14 00:00 |
12:13:10.03 |
+07:27:44.5 |
HIP 59438 |
25.10 |
| 2026-08-14 12:00 |
12:13:28.25 |
+07:26:11.1 |
HIP 59740 |
24.40 |
| 2026-08-15 00:00 |
12:13:46.55 |
+07:24:37.4 |
HIP 59740 |
20.51 |
| 2026-08-15 12:00 |
12:14:04.92 |
+07:23:03.4 |
HIP 59740 |
17.08 |
| 2026-08-16 00:00 |
12:14:23.35 |
+07:21:29.2 |
HIP 59740 |
14.44 |
| 2026-08-16 12:00 |
12:14:41.86 |
+07:19:54.8 |
HIP 59740 |
13.12 |
| 2026-08-17 00:00 |
12:15:00.43 |
+07:18:20.1 |
HIP 59740 |
13.52 |
| 2026-08-17 12:00 |
12:15:19.08 |
+07:16:45.1 |
HIP 59740 |
15.53 |
| 2026-08-18 00:00 |
12:15:37.79 |
+07:15:09.9 |
HIP 59852 |
13.61 |
| 2026-08-18 12:00 |
12:15:56.56 |
+07:13:34.5 |
HIP 59852 |
10.77 |
| 2026-08-19 00:00 |
12:16:15.41 |
+07:11:58.9 |
HIP 59852 |
9.76 |