メタデータ
| 項目 |
値 |
| Designation |
C/2015 D1 (SOHO) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-02-19T17:57:35.902080Z |
| Orbit solution date (soln_date, UTC) |
2021-04-16T12:05:35Z |
| Obs used |
417 |
| NEO |
Yes |
| M1 |
10.000 |
| K1 |
4.500 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2015-02-20.0000000 |
| e |
0.99432307 |
| q (au) |
0.028322 |
| a (au) |
4.989017 |
| i (deg) |
69.615618 |
| Ω (om, deg) |
95.881026 |
| ω (w, deg) |
234.955413 |
| M (ma, deg) |
0.022259 |
等級
散乱 + 全体線形
$$
M_a = (10.386 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.386 |
| n |
2.000 |
| 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 |
| 2015-02-18 |
2015-02-19 |
+1.3163 |
+2.493 |
| 2015-02-19 |
2015-02-20 |
+4.2155 |
+6.540 |
| 2015-02-20 |
2015-03-17 |
-1.1628 |
-1.516 |
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 |
09:02:36.35 |
+64:18:51.0 |
HIP 44625 |
25.12 |
| 2026-05-12 12:00 |
09:02:37.36 |
+64:18:15.1 |
HIP 44625 |
24.67 |
| 2026-05-13 00:00 |
09:02:38.42 |
+64:17:39.2 |
HIP 44625 |
24.22 |
| 2026-05-13 12:00 |
09:02:39.54 |
+64:17:03.3 |
HIP 44625 |
23.77 |
| 2026-05-14 00:00 |
09:02:40.72 |
+64:16:27.4 |
HIP 44625 |
23.33 |
| 2026-05-14 12:00 |
09:02:41.95 |
+64:15:51.5 |
HIP 44625 |
22.88 |
| 2026-05-15 00:00 |
09:02:43.25 |
+64:15:15.5 |
HIP 44625 |
22.44 |
| 2026-05-15 12:00 |
09:02:44.60 |
+64:14:39.6 |
HIP 44625 |
22.01 |
| 2026-05-16 00:00 |
09:02:46.01 |
+64:14:03.6 |
HIP 44625 |
21.57 |
| 2026-05-16 12:00 |
09:02:47.47 |
+64:13:27.7 |
HIP 44625 |
21.14 |
| 2026-05-17 00:00 |
09:02:48.99 |
+64:12:51.7 |
HIP 44625 |
20.72 |
| 2026-05-17 12:00 |
09:02:50.57 |
+64:12:15.8 |
HIP 44625 |
20.29 |
| 2026-05-18 00:00 |
09:02:52.21 |
+64:11:39.8 |
HIP 44625 |
19.88 |
| 2026-05-18 12:00 |
09:02:53.90 |
+64:11:03.9 |
HIP 44625 |
19.47 |
| 2026-05-19 00:00 |
09:02:55.64 |
+64:10:28.0 |
HIP 44625 |
19.06 |
| 2026-05-19 12:00 |
09:02:57.44 |
+64:09:52.1 |
HIP 44625 |
18.66 |
| 2026-05-20 00:00 |
09:02:59.30 |
+64:09:16.2 |
HIP 44625 |
18.27 |
| 2026-05-20 12:00 |
09:03:01.21 |
+64:08:40.3 |
HIP 44625 |
17.89 |
| 2026-05-21 00:00 |
09:03:03.18 |
+64:08:04.5 |
HIP 44625 |
17.51 |
| 2026-05-21 12:00 |
09:03:05.20 |
+64:07:28.7 |
HIP 44625 |
17.15 |
| 2026-05-22 00:00 |
09:03:07.27 |
+64:06:52.9 |
HIP 44625 |
16.79 |
| 2026-05-22 12:00 |
09:03:09.40 |
+64:06:17.1 |
HIP 44625 |
16.45 |
| 2026-05-23 00:00 |
09:03:11.58 |
+64:05:41.4 |
HIP 44625 |
16.12 |
| 2026-05-23 12:00 |
09:03:13.82 |
+64:05:05.7 |
HIP 44625 |
15.80 |
| 2026-05-24 00:00 |
09:03:16.11 |
+64:04:30.0 |
HIP 44625 |
15.50 |
| 2026-05-24 12:00 |
09:03:18.45 |
+64:03:54.4 |
HIP 44625 |
15.21 |
| 2026-05-25 00:00 |
09:03:20.84 |
+64:03:18.9 |
HIP 44625 |
14.93 |
| 2026-05-25 12:00 |
09:03:23.29 |
+64:02:43.3 |
HIP 44625 |
14.68 |
| 2026-05-26 00:00 |
09:03:25.78 |
+64:02:07.8 |
HIP 44625 |
14.44 |
| 2026-05-26 12:00 |
09:03:28.33 |
+64:01:32.4 |
HIP 44625 |
14.23 |
| 2026-05-27 00:00 |
09:03:30.93 |
+64:00:57.0 |
HIP 44625 |
14.03 |
| 2026-05-27 12:00 |
09:03:33.58 |
+64:00:21.7 |
HIP 44625 |
13.86 |
| 2026-05-28 00:00 |
09:03:36.28 |
+63:59:46.4 |
HIP 44625 |
13.71 |
| 2026-05-28 12:00 |
09:03:39.03 |
+63:59:11.2 |
HIP 44625 |
13.59 |
| 2026-05-29 00:00 |
09:03:41.83 |
+63:58:36.0 |
HIP 44625 |
13.49 |
| 2026-05-29 12:00 |
09:03:44.69 |
+63:58:00.9 |
HIP 44625 |
13.42 |
| 2026-05-30 00:00 |
09:03:47.59 |
+63:57:25.8 |
HIP 44625 |
13.37 |
| 2026-05-30 12:00 |
09:03:50.54 |
+63:56:50.8 |
HIP 44625 |
13.36 |
| 2026-05-31 00:00 |
09:03:53.53 |
+63:56:15.9 |
HIP 44625 |
13.37 |
| 2026-05-31 12:00 |
09:03:56.58 |
+63:55:41.1 |
HIP 44625 |
13.41 |
| 2026-06-01 00:00 |
09:03:59.68 |
+63:55:06.3 |
HIP 44625 |
13.47 |
| 2026-06-01 12:00 |
09:04:02.82 |
+63:54:31.6 |
HIP 44625 |
13.57 |
| 2026-06-02 00:00 |
09:04:06.01 |
+63:53:57.0 |
HIP 44625 |
13.69 |