メタデータ
| 項目 |
値 |
| Designation |
C/2025 W2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2025-12-07T20:01:40.048320Z |
| Orbit solution date (soln_date, UTC) |
2026-01-07T15:42:51Z |
| Obs used |
54 |
| NEO |
- |
| M1 |
15.400 |
| K1 |
23.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2025-11-28T14:38:51.734400Z |
| Discovery magnitude (MPC) |
19.16 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2025-12-01.0000000 |
| e |
0.94608895 |
| q (au) |
1.453281 |
| a (au) |
26.957020 |
| i (deg) |
94.710549 |
| Ω (om, deg) |
90.844949 |
| ω (w, deg) |
41.034555 |
| M (ma, deg) |
359.951871 |
等級
散乱 + 全体線形
$$
M_a = (16.538 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
16.538 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.948 |
| 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
天体暦
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
19:21:10.64 |
+46:51:29.9 |
HIP 94976 |
27.05 |
| 2026-06-01 12:00 |
19:19:53.57 |
+46:48:53.8 |
HIP 94976 |
19.43 |
| 2026-06-02 00:00 |
19:18:36.26 |
+46:46:09.7 |
HIP 94976 |
19.57 |
| 2026-06-02 12:00 |
19:17:18.72 |
+46:43:17.6 |
HIP 94755 |
17.25 |
| 2026-06-03 00:00 |
19:16:00.98 |
+46:40:17.5 |
HIP 94776 |
18.98 |
| 2026-06-03 12:00 |
19:14:43.05 |
+46:37:09.3 |
HIP 94438 |
26.43 |
| 2026-06-04 00:00 |
19:13:24.95 |
+46:33:52.9 |
HIP 94335 |
19.97 |
| 2026-06-04 12:00 |
19:12:06.69 |
+46:30:28.4 |
HIP 94335 |
11.04 |
| 2026-06-05 00:00 |
19:10:48.28 |
+46:26:55.6 |
HIP 94335 |
15.18 |
| 2026-06-05 12:00 |
19:09:29.75 |
+46:23:14.6 |
HIP 94335 |
27.03 |
| 2026-06-06 00:00 |
19:08:11.11 |
+46:19:25.2 |
HIP 93913 |
16.69 |
| 2026-06-06 12:00 |
19:06:52.37 |
+46:15:27.5 |
HIP 93913 |
11.50 |
| 2026-06-07 00:00 |
19:05:33.56 |
+46:11:21.5 |
HIP 93673 |
19.19 |
| 2026-06-07 12:00 |
19:04:14.69 |
+46:07:07.1 |
HIP 93673 |
12.24 |
| 2026-06-08 00:00 |
19:02:55.78 |
+46:02:44.2 |
HIP 93673 |
18.46 |
| 2026-06-08 12:00 |
19:01:36.84 |
+45:58:13.0 |
HIP 93320 |
20.60 |
| 2026-06-09 00:00 |
19:00:17.89 |
+45:53:33.2 |
HIP 93320 |
12.10 |
| 2026-06-09 12:00 |
18:58:58.95 |
+45:48:45.0 |
HIP 93061 |
16.68 |
| 2026-06-10 00:00 |
18:57:40.04 |
+45:43:48.3 |
HIP 93061 |
6.72 |
| 2026-06-10 12:00 |
18:56:21.17 |
+45:38:43.1 |
HIP 92961 |
7.84 |
| 2026-06-11 00:00 |
18:55:02.35 |
+45:33:29.5 |
HIP 92961 |
14.06 |
| 2026-06-11 12:00 |
18:53:43.62 |
+45:28:07.3 |
HIP 92961 |
27.76 |
| 2026-06-12 00:00 |
18:52:24.97 |
+45:22:36.6 |
HIP 92541 |
17.55 |
| 2026-06-12 12:00 |
18:51:06.44 |
+45:16:57.5 |
HIP 92541 |
9.82 |
| 2026-06-13 00:00 |
18:49:48.03 |
+45:11:09.9 |
HIP 92334 |
10.85 |
| 2026-06-13 12:00 |
18:48:29.77 |
+45:05:13.8 |
HIP 92291 |
10.53 |
| 2026-06-14 00:00 |
18:47:11.67 |
+44:59:09.2 |
HIP 92132 |
18.81 |
| 2026-06-14 12:00 |
18:45:53.74 |
+44:52:56.3 |
HIP 92132 |
14.56 |
| 2026-06-15 00:00 |
18:44:36.01 |
+44:46:34.9 |
HIP 91927 |
7.17 |
| 2026-06-15 12:00 |
18:43:18.50 |
+44:40:05.2 |
HIP 91782 |
15.97 |
| 2026-06-16 00:00 |
18:42:01.20 |
+44:33:27.1 |
HIP 91739 |
17.68 |
| 2026-06-16 12:00 |
18:40:44.16 |
+44:26:40.8 |
HIP 91615 |
10.97 |
| 2026-06-17 00:00 |
18:39:27.37 |
+44:19:46.2 |
HIP 91615 |
17.55 |
| 2026-06-17 12:00 |
18:38:10.86 |
+44:12:43.4 |
HIP 91249 |
19.49 |
| 2026-06-18 00:00 |
18:36:54.64 |
+44:05:32.5 |
HIP 91274 |
11.35 |
| 2026-06-18 12:00 |
18:35:38.73 |
+43:58:13.5 |
HIP 91213 |
13.52 |
| 2026-06-19 00:00 |
18:34:23.13 |
+43:50:46.4 |
HIP 91213 |
22.45 |
| 2026-06-19 12:00 |
18:33:07.88 |
+43:43:11.4 |
HIP 90819 |
24.46 |
| 2026-06-20 00:00 |
18:31:52.97 |
+43:35:28.5 |
HIP 90681 |
24.08 |
| 2026-06-20 12:00 |
18:30:38.43 |
+43:27:37.8 |
HIP 90681 |
8.86 |
| 2026-06-21 00:00 |
18:29:24.26 |
+43:19:39.4 |
HIP 90681 |
8.09 |
| 2026-06-21 12:00 |
18:28:10.49 |
+43:11:33.2 |
HIP 90681 |
23.32 |
| 2026-06-22 00:00 |
18:26:57.12 |
+43:03:19.5 |
HIP 90351 |
22.51 |