メタデータ
| 項目 |
値 |
| Designation |
C/2015 X7 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-07-30T05:59:33.682560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:20Z |
| Obs used |
620 |
| NEO |
- |
| M1 |
11.600 |
| K1 |
6.000 |
| PC |
- |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2016-09-22.0000000 |
| e |
1.00189036 |
| q (au) |
3.684550 |
| a (au) |
-1949.127032 |
| i (deg) |
57.578925 |
| Ω (om, deg) |
139.884070 |
| ω (w, deg) |
348.488537 |
| M (ma, deg) |
0.000616 |
等級
散乱 + 全体線形
$$
M_a = (11.078 + 2.092\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
11.078 |
| n |
2.092 |
| gf |
1.000 |
| gb |
-0.998 |
| 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 |
| 2015-01-28 |
2016-05-01 |
-0.2726 |
-0.309 |
| 2016-11-02 |
2017-06-16 |
-0.5340 |
+0.555 |
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 |
18:33:50.26 |
+23:22:01.7 |
HIP 90915 |
20.99 |
| 2026-03-26 12:00 |
18:33:51.10 |
+23:22:53.7 |
HIP 90915 |
20.52 |
| 2026-03-27 00:00 |
18:33:51.88 |
+23:23:45.6 |
HIP 90915 |
20.06 |
| 2026-03-27 12:00 |
18:33:52.62 |
+23:24:37.6 |
HIP 90915 |
19.63 |
| 2026-03-28 00:00 |
18:33:53.30 |
+23:25:29.6 |
HIP 90915 |
19.22 |
| 2026-03-28 12:00 |
18:33:53.94 |
+23:26:21.5 |
HIP 90915 |
18.84 |
| 2026-03-29 00:00 |
18:33:54.53 |
+23:27:13.5 |
HIP 90915 |
18.48 |
| 2026-03-29 12:00 |
18:33:55.07 |
+23:28:05.4 |
HIP 90915 |
18.14 |
| 2026-03-30 00:00 |
18:33:55.56 |
+23:28:57.3 |
HIP 90915 |
17.83 |
| 2026-03-30 12:00 |
18:33:56.00 |
+23:29:49.2 |
HIP 90915 |
17.55 |
| 2026-03-31 00:00 |
18:33:56.39 |
+23:30:41.0 |
HIP 90915 |
17.29 |
| 2026-03-31 12:00 |
18:33:56.74 |
+23:31:32.9 |
HIP 90915 |
17.07 |
| 2026-04-01 00:00 |
18:33:57.03 |
+23:32:24.6 |
HIP 90915 |
16.88 |
| 2026-04-01 12:00 |
18:33:57.28 |
+23:33:16.4 |
HIP 90915 |
16.72 |
| 2026-04-02 00:00 |
18:33:57.47 |
+23:34:08.1 |
HIP 90915 |
16.59 |
| 2026-04-02 12:00 |
18:33:57.62 |
+23:34:59.8 |
HIP 90915 |
16.50 |
| 2026-04-03 00:00 |
18:33:57.72 |
+23:35:51.4 |
HIP 90915 |
16.44 |
| 2026-04-03 12:00 |
18:33:57.77 |
+23:36:43.0 |
HIP 90915 |
16.41 |
| 2026-04-04 00:00 |
18:33:57.77 |
+23:37:34.5 |
HIP 90915 |
16.41 |
| 2026-04-04 12:00 |
18:33:57.72 |
+23:38:25.9 |
HIP 90915 |
16.45 |
| 2026-04-05 00:00 |
18:33:57.62 |
+23:39:17.3 |
HIP 90915 |
16.53 |
| 2026-04-05 12:00 |
18:33:57.47 |
+23:40:08.6 |
HIP 90915 |
16.63 |
| 2026-04-06 00:00 |
18:33:57.28 |
+23:40:59.8 |
HIP 90915 |
16.77 |
| 2026-04-06 12:00 |
18:33:57.03 |
+23:41:51.0 |
HIP 90915 |
16.94 |
| 2026-04-07 00:00 |
18:33:56.74 |
+23:42:42.0 |
HIP 90915 |
17.14 |
| 2026-04-07 12:00 |
18:33:56.39 |
+23:43:33.0 |
HIP 90915 |
17.36 |
| 2026-04-08 00:00 |
18:33:56.00 |
+23:44:23.9 |
HIP 90915 |
17.62 |
| 2026-04-08 12:00 |
18:33:55.56 |
+23:45:14.7 |
HIP 90915 |
17.90 |
| 2026-04-09 00:00 |
18:33:55.07 |
+23:46:05.4 |
HIP 90915 |
18.21 |
| 2026-04-09 12:00 |
18:33:54.53 |
+23:46:56.0 |
HIP 90915 |
18.54 |
| 2026-04-10 00:00 |
18:33:53.94 |
+23:47:46.5 |
HIP 90915 |
18.89 |
| 2026-04-10 12:00 |
18:33:53.30 |
+23:48:36.8 |
HIP 90915 |
19.26 |
| 2026-04-11 00:00 |
18:33:52.62 |
+23:49:27.1 |
HIP 90915 |
19.66 |
| 2026-04-11 12:00 |
18:33:51.89 |
+23:50:17.2 |
HIP 90915 |
20.07 |
| 2026-04-12 00:00 |
18:33:51.10 |
+23:51:07.2 |
HIP 90915 |
20.50 |
| 2026-04-12 12:00 |
18:33:50.27 |
+23:51:57.1 |
HIP 90915 |
20.95 |
| 2026-04-13 00:00 |
18:33:49.39 |
+23:52:46.9 |
HIP 90920 |
21.02 |
| 2026-04-13 12:00 |
18:33:48.46 |
+23:53:36.5 |
HIP 90920 |
20.27 |
| 2026-04-14 00:00 |
18:33:47.48 |
+23:54:25.9 |
HIP 90920 |
19.51 |
| 2026-04-14 12:00 |
18:33:46.46 |
+23:55:15.3 |
HIP 90920 |
18.76 |
| 2026-04-15 00:00 |
18:33:45.39 |
+23:56:04.4 |
HIP 90920 |
18.01 |
| 2026-04-15 12:00 |
18:33:44.26 |
+23:56:53.4 |
HIP 90920 |
17.27 |
| 2026-04-16 00:00 |
18:33:43.09 |
+23:57:42.3 |
HIP 90920 |
16.53 |