C/2015 V2 (Johnson)
メタデータ
| 項目 |
値 |
| Designation |
C/2015 V2 (Johnson) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-06-12T08:20:20.379840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:16Z |
| Obs used |
5886 |
| NEO |
- |
| 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) |
2017-01-18.0000000 |
| e |
1.00170268 |
| q (au) |
1.636950 |
| a (au) |
-961.396893 |
| i (deg) |
49.874813 |
| Ω (om, deg) |
69.852102 |
| ω (w, deg) |
164.898092 |
| M (ma, deg) |
-0.004806 |
等級
散乱 + 全体線形
$$
M_a = (12.188 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.188 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.781 |
| 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
残差 (区間線形)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| 開始日 (UTC) |
終了日 (UTC) |
a |
b |
| 2015-01-11 |
2017-06-11 |
+1.6700 |
-1.347 |
| 2017-06-12 |
2019-10-27 |
+2.6251 |
-1.868 |
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) |
| 2026-02-03 00:00 |
02:47:39.94 |
-19:16:03.8 |
HIP 13130 |
22.62 |
| 2026-02-03 12:00 |
02:47:40.18 |
-19:15:11.7 |
HIP 13130 |
22.04 |
| 2026-02-04 00:00 |
02:47:40.46 |
-19:14:19.5 |
HIP 13130 |
21.46 |
| 2026-02-04 12:00 |
02:47:40.78 |
-19:13:27.2 |
HIP 13130 |
20.89 |
| 2026-02-05 00:00 |
02:47:41.15 |
-19:12:34.7 |
HIP 13130 |
20.34 |
| 2026-02-05 12:00 |
02:47:41.57 |
-19:11:42.1 |
HIP 13130 |
19.80 |
| 2026-02-06 00:00 |
02:47:42.04 |
-19:10:49.5 |
HIP 13130 |
19.27 |
| 2026-02-06 12:00 |
02:47:42.55 |
-19:09:56.7 |
HIP 13130 |
18.76 |
| 2026-02-07 00:00 |
02:47:43.11 |
-19:09:03.8 |
HIP 13130 |
18.26 |
| 2026-02-07 12:00 |
02:47:43.71 |
-19:08:10.8 |
HIP 13130 |
17.79 |
| 2026-02-08 00:00 |
02:47:44.37 |
-19:07:17.7 |
HIP 13130 |
17.34 |
| 2026-02-08 12:00 |
02:47:45.06 |
-19:06:24.5 |
HIP 13130 |
16.92 |
| 2026-02-09 00:00 |
02:47:45.81 |
-19:05:31.3 |
HIP 13130 |
16.52 |
| 2026-02-09 12:00 |
02:47:46.60 |
-19:04:37.9 |
HIP 13130 |
16.15 |
| 2026-02-10 00:00 |
02:47:47.43 |
-19:03:44.5 |
HIP 13130 |
15.81 |
| 2026-02-10 12:00 |
02:47:48.31 |
-19:02:50.9 |
HIP 13130 |
15.51 |
| 2026-02-11 00:00 |
02:47:49.24 |
-19:01:57.3 |
HIP 13130 |
15.25 |
| 2026-02-11 12:00 |
02:47:50.21 |
-19:01:03.7 |
HIP 13130 |
15.03 |
| 2026-02-12 00:00 |
02:47:51.23 |
-19:00:09.9 |
HIP 13130 |
14.85 |
| 2026-02-12 12:00 |
02:47:52.30 |
-18:59:16.1 |
HIP 13130 |
14.72 |
| 2026-02-13 00:00 |
02:47:53.41 |
-18:58:22.2 |
HIP 13130 |
14.63 |
| 2026-02-13 12:00 |
02:47:54.56 |
-18:57:28.3 |
HIP 13130 |
14.60 |
| 2026-02-14 00:00 |
02:47:55.76 |
-18:56:34.3 |
HIP 13130 |
14.62 |
| 2026-02-14 12:00 |
02:47:57.00 |
-18:55:40.3 |
HIP 13130 |
14.68 |
| 2026-02-15 00:00 |
02:47:58.29 |
-18:54:46.2 |
HIP 13087 |
14.33 |
| 2026-02-15 12:00 |
02:47:59.63 |
-18:53:52.1 |
HIP 13087 |
13.37 |
| 2026-02-16 00:00 |
02:48:01.00 |
-18:52:57.9 |
HIP 13087 |
12.42 |
| 2026-02-16 12:00 |
02:48:02.43 |
-18:52:03.8 |
HIP 13087 |
11.46 |
| 2026-02-17 00:00 |
02:48:03.89 |
-18:51:09.5 |
HIP 13087 |
10.50 |
| 2026-02-17 12:00 |
02:48:05.40 |
-18:50:15.3 |
HIP 13087 |
9.54 |
| 2026-02-18 00:00 |
02:48:06.96 |
-18:49:21.0 |
HIP 13087 |
8.57 |
| 2026-02-18 12:00 |
02:48:08.56 |
-18:48:26.7 |
HIP 13087 |
7.61 |
| 2026-02-19 00:00 |
02:48:10.20 |
-18:47:32.4 |
HIP 13087 |
6.66 |
| 2026-02-19 12:00 |
02:48:11.88 |
-18:46:38.0 |
HIP 13087 |
5.71 |
| 2026-02-20 00:00 |
02:48:13.61 |
-18:45:43.7 |
HIP 13087 |
4.77 |
| 2026-02-20 12:00 |
02:48:15.38 |
-18:44:49.4 |
HIP 13087 |
3.87 |
| 2026-02-21 00:00 |
02:48:17.19 |
-18:43:55.0 |
HIP 13087 |
3.04 |
| 2026-02-21 12:00 |
02:48:19.05 |
-18:43:00.7 |
HIP 13087 |
2.34 |
| 2026-02-22 00:00 |
02:48:20.95 |
-18:42:06.3 |
HIP 13087 |
1.94 |
| 2026-02-22 12:00 |
02:48:22.89 |
-18:41:12.0 |
HIP 13087 |
2.03 |
| 2026-02-23 00:00 |
02:48:24.87 |
-18:40:17.7 |
HIP 13087 |
2.58 |
| 2026-02-23 12:00 |
02:48:26.90 |
-18:39:23.4 |
HIP 13087 |
3.36 |
| 2026-02-24 00:00 |
02:48:28.96 |
-18:38:29.1 |
HIP 13087 |
4.25 |