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) |
| 2026-03-26 00:00 |
09:05:33.55 |
+65:07:36.4 |
HIP 44788 |
15.91 |
| 2026-03-26 12:00 |
09:05:28.88 |
+65:07:13.7 |
HIP 44788 |
16.14 |
| 2026-03-27 00:00 |
09:05:24.26 |
+65:06:50.7 |
HIP 44788 |
16.38 |
| 2026-03-27 12:00 |
09:05:19.69 |
+65:06:27.5 |
HIP 44788 |
16.63 |
| 2026-03-28 00:00 |
09:05:15.18 |
+65:06:04.1 |
HIP 44788 |
16.90 |
| 2026-03-28 12:00 |
09:05:10.73 |
+65:05:40.4 |
HIP 44788 |
17.17 |
| 2026-03-29 00:00 |
09:05:06.33 |
+65:05:16.4 |
HIP 44788 |
17.46 |
| 2026-03-29 12:00 |
09:05:01.99 |
+65:04:52.2 |
HIP 44788 |
17.76 |
| 2026-03-30 00:00 |
09:04:57.71 |
+65:04:27.8 |
HIP 44788 |
18.06 |
| 2026-03-30 12:00 |
09:04:53.49 |
+65:04:03.1 |
HIP 44788 |
18.37 |
| 2026-03-31 00:00 |
09:04:49.32 |
+65:03:38.2 |
HIP 44788 |
18.69 |
| 2026-03-31 12:00 |
09:04:45.21 |
+65:03:13.0 |
HIP 44666 |
18.68 |
| 2026-04-01 00:00 |
09:04:41.16 |
+65:02:47.6 |
HIP 44666 |
18.52 |
| 2026-04-01 12:00 |
09:04:37.16 |
+65:02:22.0 |
HIP 44666 |
18.37 |
| 2026-04-02 00:00 |
09:04:33.22 |
+65:01:56.2 |
HIP 44666 |
18.23 |
| 2026-04-02 12:00 |
09:04:29.35 |
+65:01:30.1 |
HIP 44666 |
18.11 |
| 2026-04-03 00:00 |
09:04:25.53 |
+65:01:03.8 |
HIP 44666 |
18.00 |
| 2026-04-03 12:00 |
09:04:21.77 |
+65:00:37.3 |
HIP 44666 |
17.90 |
| 2026-04-04 00:00 |
09:04:18.06 |
+65:00:10.5 |
HIP 44666 |
17.82 |
| 2026-04-04 12:00 |
09:04:14.42 |
+64:59:43.5 |
HIP 44666 |
17.75 |
| 2026-04-05 00:00 |
09:04:10.84 |
+64:59:16.4 |
HIP 44666 |
17.69 |
| 2026-04-05 12:00 |
09:04:07.31 |
+64:58:49.0 |
HIP 44666 |
17.64 |
| 2026-04-06 00:00 |
09:04:03.85 |
+64:58:21.4 |
HIP 44666 |
17.60 |
| 2026-04-06 12:00 |
09:04:00.44 |
+64:57:53.6 |
HIP 44666 |
17.58 |
| 2026-04-07 00:00 |
09:03:57.10 |
+64:57:25.6 |
HIP 44666 |
17.57 |
| 2026-04-07 12:00 |
09:03:53.82 |
+64:56:57.4 |
HIP 44666 |
17.58 |
| 2026-04-08 00:00 |
09:03:50.59 |
+64:56:28.9 |
HIP 44666 |
17.59 |
| 2026-04-08 12:00 |
09:03:47.43 |
+64:56:00.3 |
HIP 44666 |
17.62 |
| 2026-04-09 00:00 |
09:03:44.33 |
+64:55:31.5 |
HIP 44666 |
17.66 |
| 2026-04-09 12:00 |
09:03:41.28 |
+64:55:02.5 |
HIP 44666 |
17.72 |
| 2026-04-10 00:00 |
09:03:38.30 |
+64:54:33.3 |
HIP 44666 |
17.78 |
| 2026-04-10 12:00 |
09:03:35.38 |
+64:54:03.9 |
HIP 44666 |
17.86 |
| 2026-04-11 00:00 |
09:03:32.52 |
+64:53:34.4 |
HIP 44666 |
17.94 |
| 2026-04-11 12:00 |
09:03:29.73 |
+64:53:04.6 |
HIP 44666 |
18.04 |
| 2026-04-12 00:00 |
09:03:26.99 |
+64:52:34.7 |
HIP 44666 |
18.15 |
| 2026-04-12 12:00 |
09:03:24.32 |
+64:52:04.6 |
HIP 44666 |
18.27 |
| 2026-04-13 00:00 |
09:03:21.71 |
+64:51:34.3 |
HIP 44666 |
18.40 |
| 2026-04-13 12:00 |
09:03:19.16 |
+64:51:03.9 |
HIP 44666 |
18.54 |
| 2026-04-14 00:00 |
09:03:16.67 |
+64:50:33.2 |
HIP 44666 |
18.69 |
| 2026-04-14 12:00 |
09:03:14.24 |
+64:50:02.4 |
HIP 44666 |
18.85 |
| 2026-04-15 00:00 |
09:03:11.88 |
+64:49:31.5 |
HIP 44666 |
19.02 |
| 2026-04-15 12:00 |
09:03:09.58 |
+64:49:00.3 |
HIP 44666 |
19.20 |
| 2026-04-16 00:00 |
09:03:07.34 |
+64:48:29.1 |
HIP 44666 |
19.39 |