メタデータ
| 項目 |
値 |
| Designation |
C/2024 G2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2025-06-13T13:01:21.555840Z |
| Orbit solution date (soln_date, UTC) |
2026-05-28T12:12:15Z |
| Obs used |
669 |
| NEO |
- |
| M1 |
4.600 |
| K1 |
13.750 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2024-04-08T07:54:38.131200Z |
| Discovery magnitude (MPC) |
18.63 o |
| Discovery observatory (MPC) |
W68 · ATLAS Chile, Rio Hurtado |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2025-08-13.0000000 |
| e |
0.99265479 |
| q (au) |
5.348247 |
| a (au) |
728.127328 |
| i (deg) |
122.124048 |
| Ω (om, deg) |
171.397617 |
| ω (w, deg) |
328.738958 |
| M (ma, deg) |
0.003033 |
等級
散乱 + 全体線形
$$
M_a = (2.899 + 5.912\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
2.899 |
| n |
5.912 |
| gf |
0.889 |
| gb |
-0.993 |
| k |
1.000 |
| δ90 |
8.559 |
| 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 |
| 2024-04-08 |
2025-06-12 |
-4.1033 |
+2.737 |
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) |
| 2026-07-29 00:00 |
10:59:17.97 |
+15:11:39.4 |
HIP 53710 |
20.78 |
| 2026-07-29 12:00 |
10:59:29.36 |
+15:12:13.1 |
HIP 53710 |
20.31 |
| 2026-07-30 00:00 |
10:59:40.81 |
+15:12:46.4 |
HIP 53710 |
20.22 |
| 2026-07-30 12:00 |
10:59:52.32 |
+15:13:19.4 |
HIP 53822 |
18.41 |
| 2026-07-31 00:00 |
11:00:03.89 |
+15:13:52.1 |
HIP 53822 |
16.26 |
| 2026-07-31 12:00 |
11:00:15.52 |
+15:14:24.4 |
HIP 53822 |
14.35 |
| 2026-08-01 00:00 |
11:00:27.21 |
+15:14:56.5 |
HIP 53822 |
12.79 |
| 2026-08-01 12:00 |
11:00:38.95 |
+15:15:28.3 |
HIP 53822 |
11.74 |
| 2026-08-02 00:00 |
11:00:50.76 |
+15:15:59.7 |
HIP 53822 |
11.36 |
| 2026-08-02 12:00 |
11:01:02.62 |
+15:16:30.9 |
HIP 53822 |
11.71 |
| 2026-08-03 00:00 |
11:01:14.53 |
+15:17:01.9 |
HIP 53822 |
12.74 |
| 2026-08-03 12:00 |
11:01:26.50 |
+15:17:32.5 |
HIP 53822 |
14.31 |
| 2026-08-04 00:00 |
11:01:38.53 |
+15:18:02.9 |
HIP 53822 |
16.28 |
| 2026-08-04 12:00 |
11:01:50.61 |
+15:18:33.1 |
HIP 53822 |
18.53 |
| 2026-08-05 00:00 |
11:02:02.74 |
+15:19:03.0 |
HIP 53881 |
20.46 |
| 2026-08-05 12:00 |
11:02:14.92 |
+15:19:32.7 |
HIP 53881 |
22.32 |
| 2026-08-06 00:00 |
11:02:27.16 |
+15:20:02.1 |
HIP 53881 |
24.40 |
| 2026-08-06 12:00 |
11:02:39.45 |
+15:20:31.3 |
HIP 53881 |
26.67 |
| 2026-08-07 00:00 |
11:02:51.78 |
+15:21:00.3 |
HIP 53881 |
29.07 |
| 2026-08-07 12:00 |
11:03:04.17 |
+15:21:29.1 |
HIP 53881 |
31.59 |
| 2026-08-08 00:00 |
11:03:16.61 |
+15:21:57.7 |
HIP 53881 |
34.20 |
| 2026-08-08 12:00 |
11:03:29.09 |
+15:22:26.1 |
HIP 53881 |
36.88 |
| 2026-08-09 00:00 |
11:03:41.63 |
+15:22:54.3 |
HIP 53881 |
39.62 |
| 2026-08-09 12:00 |
11:03:54.20 |
+15:23:22.4 |
HIP 54113 |
40.41 |
| 2026-08-10 00:00 |
11:04:06.83 |
+15:23:50.3 |
HIP 54318 |
40.02 |
| 2026-08-10 12:00 |
11:04:19.50 |
+15:24:18.0 |
HIP 54318 |
37.30 |
| 2026-08-11 00:00 |
11:04:32.21 |
+15:24:45.6 |
HIP 54318 |
34.64 |
| 2026-08-11 12:00 |
11:04:44.97 |
+15:25:13.0 |
HIP 54318 |
32.04 |
| 2026-08-12 00:00 |
11:04:57.77 |
+15:25:40.3 |
HIP 54318 |
29.53 |
| 2026-08-12 12:00 |
11:05:10.61 |
+15:26:07.5 |
HIP 54318 |
27.14 |
| 2026-08-13 00:00 |
11:05:23.50 |
+15:26:34.5 |
HIP 54318 |
24.91 |
| 2026-08-13 12:00 |
11:05:36.42 |
+15:27:01.5 |
HIP 54318 |
22.89 |
| 2026-08-14 00:00 |
11:05:49.38 |
+15:27:28.3 |
HIP 54318 |
21.13 |
| 2026-08-14 12:00 |
11:06:02.39 |
+15:27:55.1 |
HIP 54318 |
19.72 |
| 2026-08-15 00:00 |
11:06:15.43 |
+15:28:21.7 |
HIP 54318 |
18.74 |
| 2026-08-15 12:00 |
11:06:28.50 |
+15:28:48.3 |
HIP 54318 |
18.26 |
| 2026-08-16 00:00 |
11:06:41.62 |
+15:29:14.9 |
HIP 54318 |
18.33 |
| 2026-08-16 12:00 |
11:06:54.76 |
+15:29:41.4 |
HIP 54318 |
18.94 |
| 2026-08-17 00:00 |
11:07:07.95 |
+15:30:07.8 |
HIP 54318 |
20.06 |
| 2026-08-17 12:00 |
11:07:21.17 |
+15:30:34.2 |
HIP 54318 |
21.60 |
| 2026-08-18 00:00 |
11:07:34.42 |
+15:31:00.5 |
HIP 54459 |
20.45 |
| 2026-08-18 12:00 |
11:07:47.70 |
+15:31:26.8 |
HIP 54459 |
18.09 |
| 2026-08-19 00:00 |
11:08:01.01 |
+15:31:53.2 |
HIP 54459 |
16.03 |