C/1989 R1 (Helin-Roman)
メタデータ
| 項目 |
値 |
| Designation |
C/1989 R1 (Helin-Roman) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1989-08-20T06:57:23.126400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:38Z |
| Obs used |
19 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
1989-09-20.0000000 |
| e |
0.99999476 |
| q (au) |
1.324504 |
| a (au) |
252659.816775 |
| i (deg) |
128.133260 |
| Ω (om, deg) |
128.609412 |
| ω (w, deg) |
154.909426 |
| M (ma, deg) |
0.000000 |
等級
散乱 + 全体線形
$$
M_a = (13.756 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
13.756 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.800 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
09:49:46.50 |
-21:22:00.4 |
HIP 48231 |
14.60 |
| 2026-02-03 12:00 |
09:49:44.48 |
-21:21:54.9 |
HIP 48231 |
14.63 |
| 2026-02-04 00:00 |
09:49:42.46 |
-21:21:49.2 |
HIP 48231 |
14.66 |
| 2026-02-04 12:00 |
09:49:40.43 |
-21:21:43.4 |
HIP 48231 |
14.71 |
| 2026-02-05 00:00 |
09:49:38.40 |
-21:21:37.4 |
HIP 48231 |
14.78 |
| 2026-02-05 12:00 |
09:49:36.37 |
-21:21:31.2 |
HIP 48231 |
14.85 |
| 2026-02-06 00:00 |
09:49:34.34 |
-21:21:24.9 |
HIP 48231 |
14.94 |
| 2026-02-06 12:00 |
09:49:32.30 |
-21:21:18.4 |
HIP 48231 |
15.04 |
| 2026-02-07 00:00 |
09:49:30.26 |
-21:21:11.7 |
HIP 48231 |
15.16 |
| 2026-02-07 12:00 |
09:49:28.21 |
-21:21:04.9 |
HIP 48231 |
15.29 |
| 2026-02-08 00:00 |
09:49:26.17 |
-21:20:57.9 |
HIP 48231 |
15.43 |
| 2026-02-08 12:00 |
09:49:24.12 |
-21:20:50.8 |
HIP 48231 |
15.58 |
| 2026-02-09 00:00 |
09:49:22.07 |
-21:20:43.5 |
HIP 48231 |
15.74 |
| 2026-02-09 12:00 |
09:49:20.02 |
-21:20:36.1 |
HIP 48231 |
15.92 |
| 2026-02-10 00:00 |
09:49:17.97 |
-21:20:28.5 |
HIP 48231 |
16.11 |
| 2026-02-10 12:00 |
09:49:15.91 |
-21:20:20.7 |
HIP 48231 |
16.31 |
| 2026-02-11 00:00 |
09:49:13.86 |
-21:20:12.8 |
HIP 48231 |
16.52 |
| 2026-02-11 12:00 |
09:49:11.80 |
-21:20:04.7 |
HIP 48231 |
16.74 |
| 2026-02-12 00:00 |
09:49:09.75 |
-21:19:56.5 |
HIP 48231 |
16.97 |
| 2026-02-12 12:00 |
09:49:07.69 |
-21:19:48.2 |
HIP 48231 |
17.21 |
| 2026-02-13 00:00 |
09:49:05.63 |
-21:19:39.6 |
HIP 48231 |
17.45 |
| 2026-02-13 12:00 |
09:49:03.57 |
-21:19:30.9 |
HIP 48231 |
17.71 |
| 2026-02-14 00:00 |
09:49:01.51 |
-21:19:22.1 |
HIP 48231 |
17.98 |
| 2026-02-14 12:00 |
09:48:59.45 |
-21:19:13.1 |
HIP 48231 |
18.25 |
| 2026-02-15 00:00 |
09:48:57.40 |
-21:19:04.0 |
HIP 48231 |
18.54 |
| 2026-02-15 12:00 |
09:48:55.34 |
-21:18:54.7 |
HIP 48231 |
18.83 |
| 2026-02-16 00:00 |
09:48:53.28 |
-21:18:45.3 |
HIP 48231 |
19.13 |
| 2026-02-16 12:00 |
09:48:51.22 |
-21:18:35.7 |
HIP 48231 |
19.43 |
| 2026-02-17 00:00 |
09:48:49.17 |
-21:18:26.0 |
HIP 48231 |
19.74 |
| 2026-02-17 12:00 |
09:48:47.11 |
-21:18:16.1 |
HIP 48231 |
20.06 |
| 2026-02-18 00:00 |
09:48:45.06 |
-21:18:06.0 |
HIP 48231 |
20.38 |
| 2026-02-18 12:00 |
09:48:43.00 |
-21:17:55.9 |
HIP 48231 |
20.72 |
| 2026-02-19 00:00 |
09:48:40.95 |
-21:17:45.6 |
HIP 48231 |
21.05 |
| 2026-02-19 12:00 |
09:48:38.90 |
-21:17:35.1 |
HIP 48231 |
21.39 |
| 2026-02-20 00:00 |
09:48:36.86 |
-21:17:24.5 |
HIP 48231 |
21.74 |
| 2026-02-20 12:00 |
09:48:34.81 |
-21:17:13.8 |
HIP 48231 |
22.09 |
| 2026-02-21 00:00 |
09:48:32.77 |
-21:17:02.9 |
HIP 48231 |
22.45 |
| 2026-02-21 12:00 |
09:48:30.73 |
-21:16:51.8 |
HIP 48231 |
22.81 |
| 2026-02-22 00:00 |
09:48:28.69 |
-21:16:40.7 |
HIP 48231 |
23.17 |
| 2026-02-22 12:00 |
09:48:26.65 |
-21:16:29.4 |
HIP 48231 |
23.54 |
| 2026-02-23 00:00 |
09:48:24.62 |
-21:16:17.9 |
HIP 48231 |
23.91 |
| 2026-02-23 12:00 |
09:48:22.59 |
-21:16:06.4 |
HIP 48231 |
24.29 |
| 2026-02-24 00:00 |
09:48:20.57 |
-21:15:54.7 |
HIP 48231 |
24.67 |