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
$$
M_a = (12.183 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
12.183 |
| 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 |
+1.6631 |
-1.343 |
| 2017-06-12 |
2017-08-29 |
-9.8516 |
+0.988 |
| 2017-08-29 |
2019-10-27 |
+2.9922 |
-2.101 |
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 |
02:51:39.87 |
-17:46:47.1 |
HIP 13355 |
31.80 |
| 2026-03-26 12:00 |
02:51:44.01 |
-17:45:59.8 |
HIP 13355 |
30.96 |
| 2026-03-27 00:00 |
02:51:48.17 |
-17:45:12.8 |
HIP 13355 |
30.15 |
| 2026-03-27 12:00 |
02:51:52.36 |
-17:44:26.0 |
HIP 13355 |
29.37 |
| 2026-03-28 00:00 |
02:51:56.58 |
-17:43:39.3 |
HIP 13355 |
28.63 |
| 2026-03-28 12:00 |
02:52:00.82 |
-17:42:52.9 |
HIP 13355 |
27.94 |
| 2026-03-29 00:00 |
02:52:05.08 |
-17:42:06.7 |
HIP 13355 |
27.29 |
| 2026-03-29 12:00 |
02:52:09.37 |
-17:41:20.7 |
HIP 13355 |
26.69 |
| 2026-03-30 00:00 |
02:52:13.68 |
-17:40:35.0 |
HIP 13355 |
26.14 |
| 2026-03-30 12:00 |
02:52:18.02 |
-17:39:49.4 |
HIP 13355 |
25.65 |
| 2026-03-31 00:00 |
02:52:22.38 |
-17:39:04.1 |
HIP 13355 |
25.23 |
| 2026-03-31 12:00 |
02:52:26.76 |
-17:38:19.0 |
HIP 13355 |
24.86 |
| 2026-04-01 00:00 |
02:52:31.16 |
-17:37:34.1 |
HIP 13355 |
24.57 |
| 2026-04-01 12:00 |
02:52:35.59 |
-17:36:49.5 |
HIP 13355 |
24.34 |
| 2026-04-02 00:00 |
02:52:40.03 |
-17:36:05.0 |
HIP 13355 |
24.19 |
| 2026-04-02 12:00 |
02:52:44.50 |
-17:35:20.8 |
HIP 13355 |
24.12 |
| 2026-04-03 00:00 |
02:52:48.99 |
-17:34:36.9 |
HIP 13355 |
24.11 |
| 2026-04-03 12:00 |
02:52:53.50 |
-17:33:53.2 |
HIP 13355 |
24.19 |
| 2026-04-04 00:00 |
02:52:58.03 |
-17:33:09.7 |
HIP 13355 |
24.34 |
| 2026-04-04 12:00 |
02:53:02.59 |
-17:32:26.4 |
HIP 13355 |
24.56 |
| 2026-04-05 00:00 |
02:53:07.16 |
-17:31:43.4 |
HIP 13355 |
24.86 |
| 2026-04-05 12:00 |
02:53:11.75 |
-17:31:00.7 |
HIP 13355 |
25.23 |
| 2026-04-06 00:00 |
02:53:16.36 |
-17:30:18.2 |
HIP 13355 |
25.67 |
| 2026-04-06 12:00 |
02:53:21.00 |
-17:29:35.9 |
HIP 13355 |
26.17 |
| 2026-04-07 00:00 |
02:53:25.65 |
-17:28:53.9 |
HIP 13355 |
26.73 |
| 2026-04-07 12:00 |
02:53:30.31 |
-17:28:12.1 |
HIP 13355 |
27.35 |
| 2026-04-08 00:00 |
02:53:35.00 |
-17:27:30.6 |
HIP 13355 |
28.02 |
| 2026-04-08 12:00 |
02:53:39.71 |
-17:26:49.4 |
HIP 13355 |
28.74 |
| 2026-04-09 00:00 |
02:53:44.43 |
-17:26:08.4 |
HIP 13355 |
29.51 |
| 2026-04-09 12:00 |
02:53:49.17 |
-17:25:27.7 |
HIP 13355 |
30.33 |
| 2026-04-10 00:00 |
02:53:53.93 |
-17:24:47.2 |
HIP 13355 |
31.18 |
| 2026-04-10 12:00 |
02:53:58.71 |
-17:24:07.0 |
HIP 13355 |
32.07 |
| 2026-04-11 00:00 |
02:54:03.50 |
-17:23:27.1 |
HIP 13355 |
32.99 |
| 2026-04-11 12:00 |
02:54:08.31 |
-17:22:47.4 |
HIP 13355 |
33.95 |
| 2026-04-12 00:00 |
02:54:13.13 |
-17:22:08.0 |
HIP 13667 |
34.35 |
| 2026-04-12 12:00 |
02:54:17.97 |
-17:21:28.9 |
HIP 13667 |
33.06 |
| 2026-04-13 00:00 |
02:54:22.83 |
-17:20:50.1 |
HIP 13667 |
31.78 |
| 2026-04-13 12:00 |
02:54:27.70 |
-17:20:11.5 |
HIP 13667 |
30.51 |
| 2026-04-14 00:00 |
02:54:32.59 |
-17:19:33.2 |
HIP 13667 |
29.24 |
| 2026-04-14 12:00 |
02:54:37.49 |
-17:18:55.2 |
HIP 13667 |
27.97 |
| 2026-04-15 00:00 |
02:54:42.40 |
-17:18:17.5 |
HIP 13667 |
26.72 |
| 2026-04-15 12:00 |
02:54:47.33 |
-17:17:40.1 |
HIP 13667 |
25.47 |
| 2026-04-16 00:00 |
02:54:52.27 |
-17:17:02.9 |
HIP 13667 |
24.23 |