メタデータ
| 項目 |
値 |
| Designation |
C/1989 T1 (Helin-Roman-Alu) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1989-12-15T22:37:06.297600Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:38Z |
| Obs used |
120 |
| NEO |
- |
| M1 |
12.500 |
| K1 |
13.750 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1989-11-17.0000000 |
| e |
0.99061399 |
| q (au) |
1.047319 |
| a (au) |
111.582949 |
| i (deg) |
46.036538 |
| Ω (om, deg) |
8.519172 |
| ω (w, deg) |
68.125993 |
| M (ma, deg) |
359.975798 |
等級
散乱 + 全体線形
$$
M_a = (10.273 + 3.956\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.273 |
| n |
3.956 |
| 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 |
| 1989-10-01 |
1989-12-07 |
+5.1672 |
-0.345 |
| 1989-12-16 |
1990-11-17 |
-15.8129 |
+1.431 |
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 |
14:19:21.63 |
-52:37:29.5 |
HIP 69872 |
13.32 |
| 2026-07-29 12:00 |
14:19:21.64 |
-52:37:10.8 |
HIP 69872 |
13.29 |
| 2026-07-30 00:00 |
14:19:21.66 |
-52:36:52.2 |
HIP 69872 |
13.26 |
| 2026-07-30 12:00 |
14:19:21.72 |
-52:36:33.6 |
HIP 69872 |
13.26 |
| 2026-07-31 00:00 |
14:19:21.80 |
-52:36:15.1 |
HIP 69872 |
13.26 |
| 2026-07-31 12:00 |
14:19:21.91 |
-52:35:56.7 |
HIP 69872 |
13.27 |
| 2026-08-01 00:00 |
14:19:22.04 |
-52:35:38.4 |
HIP 69872 |
13.30 |
| 2026-08-01 12:00 |
14:19:22.21 |
-52:35:20.1 |
HIP 69872 |
13.33 |
| 2026-08-02 00:00 |
14:19:22.40 |
-52:35:01.9 |
HIP 69872 |
13.38 |
| 2026-08-02 12:00 |
14:19:22.61 |
-52:34:43.8 |
HIP 69872 |
13.43 |
| 2026-08-03 00:00 |
14:19:22.85 |
-52:34:25.7 |
HIP 69872 |
13.50 |
| 2026-08-03 12:00 |
14:19:23.12 |
-52:34:07.8 |
HIP 69872 |
13.58 |
| 2026-08-04 00:00 |
14:19:23.42 |
-52:33:49.9 |
HIP 69872 |
13.67 |
| 2026-08-04 12:00 |
14:19:23.74 |
-52:33:32.1 |
HIP 69872 |
13.76 |
| 2026-08-05 00:00 |
14:19:24.09 |
-52:33:14.4 |
HIP 69872 |
13.87 |
| 2026-08-05 12:00 |
14:19:24.47 |
-52:32:56.7 |
HIP 69872 |
13.99 |
| 2026-08-06 00:00 |
14:19:24.87 |
-52:32:39.2 |
HIP 69872 |
14.11 |
| 2026-08-06 12:00 |
14:19:25.30 |
-52:32:21.7 |
HIP 69872 |
14.25 |
| 2026-08-07 00:00 |
14:19:25.76 |
-52:32:04.3 |
HIP 69872 |
14.39 |
| 2026-08-07 12:00 |
14:19:26.24 |
-52:31:47.1 |
HIP 69872 |
14.54 |
| 2026-08-08 00:00 |
14:19:26.75 |
-52:31:29.9 |
HIP 69872 |
14.70 |
| 2026-08-08 12:00 |
14:19:27.28 |
-52:31:12.8 |
HIP 69872 |
14.87 |
| 2026-08-09 00:00 |
14:19:27.85 |
-52:30:55.8 |
HIP 69872 |
15.04 |
| 2026-08-09 12:00 |
14:19:28.43 |
-52:30:38.9 |
HIP 69872 |
15.22 |
| 2026-08-10 00:00 |
14:19:29.05 |
-52:30:22.0 |
HIP 69872 |
15.41 |
| 2026-08-10 12:00 |
14:19:29.69 |
-52:30:05.3 |
HIP 70103 |
15.30 |
| 2026-08-11 00:00 |
14:19:30.36 |
-52:29:48.7 |
HIP 70103 |
15.04 |
| 2026-08-11 12:00 |
14:19:31.05 |
-52:29:32.2 |
HIP 70103 |
14.77 |
| 2026-08-12 00:00 |
14:19:31.77 |
-52:29:15.8 |
HIP 70103 |
14.51 |
| 2026-08-12 12:00 |
14:19:32.52 |
-52:28:59.5 |
HIP 70103 |
14.24 |
| 2026-08-13 00:00 |
14:19:33.29 |
-52:28:43.3 |
HIP 70103 |
13.98 |
| 2026-08-13 12:00 |
14:19:34.09 |
-52:28:27.2 |
HIP 70103 |
13.71 |
| 2026-08-14 00:00 |
14:19:34.92 |
-52:28:11.2 |
HIP 70103 |
13.44 |
| 2026-08-14 12:00 |
14:19:35.77 |
-52:27:55.3 |
HIP 70103 |
13.17 |
| 2026-08-15 00:00 |
14:19:36.65 |
-52:27:39.5 |
HIP 70103 |
12.90 |
| 2026-08-15 12:00 |
14:19:37.55 |
-52:27:23.8 |
HIP 70103 |
12.63 |
| 2026-08-16 00:00 |
14:19:38.48 |
-52:27:08.3 |
HIP 70103 |
12.36 |
| 2026-08-16 12:00 |
14:19:39.43 |
-52:26:52.8 |
HIP 70103 |
12.09 |
| 2026-08-17 00:00 |
14:19:40.41 |
-52:26:37.5 |
HIP 70103 |
11.82 |
| 2026-08-17 12:00 |
14:19:41.41 |
-52:26:22.3 |
HIP 70103 |
11.54 |
| 2026-08-18 00:00 |
14:19:42.44 |
-52:26:07.2 |
HIP 70103 |
11.27 |
| 2026-08-18 12:00 |
14:19:43.50 |
-52:25:52.2 |
HIP 70103 |
10.99 |
| 2026-08-19 00:00 |
14:19:44.58 |
-52:25:37.4 |
HIP 70103 |
10.72 |