メタデータ
| 項目 |
値 |
| Designation |
C/2018 F1 (Grauer) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-12-14T01:55:08.552640Z |
| Orbit solution date (soln_date, UTC) |
2021-09-04T23:42:57Z |
| Obs used |
221 |
| NEO |
- |
| M1 |
12.700 |
| K1 |
6.250 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2018-03-17T08:17:23.424000Z |
| Discovery magnitude (MPC) |
19.10 T |
| Discovery observatory (MPC) |
G96 · University of Arizona Mt. Lemmon Survey |
オスキュレーティング軌道要素
| 項目 |
値 |
| Epoch (epoch_cal, TDB) |
2019-03-06.0000000 |
| e |
0.99071069 |
| q (au) |
2.993048 |
| a (au) |
322.203595 |
| i (deg) |
46.070619 |
| Ω (om, deg) |
177.285875 |
| ω (w, deg) |
71.628120 |
| M (ma, deg) |
0.013960 |
等級
散乱 + 全体線形
$$
M_a = (10.042 + 4.054\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
モデル定数
| 項目 |
値 |
| H0 |
10.042 |
| n |
4.054 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
1.000 |
| δ90 |
1.000 |
| 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 |
| 2017-12-22 |
2018-07-16 |
+4.3609 |
-2.361 |
| 2019-03-22 |
2019-08-08 |
-24.0881 |
+12.948 |
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 |
01:37:21.04 |
-09:45:21.7 |
HIP 7580 |
21.51 |
| 2026-07-29 12:00 |
01:37:20.71 |
-09:46:03.0 |
HIP 7580 |
22.20 |
| 2026-07-30 00:00 |
01:37:20.33 |
-09:46:44.5 |
HIP 7580 |
22.90 |
| 2026-07-30 12:00 |
01:37:19.89 |
-09:47:26.3 |
HIP 7580 |
23.60 |
| 2026-07-31 00:00 |
01:37:19.41 |
-09:48:08.3 |
HIP 7580 |
24.31 |
| 2026-07-31 12:00 |
01:37:18.88 |
-09:48:50.5 |
HIP 7580 |
25.03 |
| 2026-08-01 00:00 |
01:37:18.30 |
-09:49:33.0 |
HIP 7580 |
25.75 |
| 2026-08-01 12:00 |
01:37:17.67 |
-09:50:15.7 |
HIP 7580 |
26.48 |
| 2026-08-02 00:00 |
01:37:16.99 |
-09:50:58.7 |
HIP 7580 |
27.21 |
| 2026-08-02 12:00 |
01:37:16.27 |
-09:51:41.8 |
HIP 7580 |
27.95 |
| 2026-08-03 00:00 |
01:37:15.49 |
-09:52:25.2 |
HIP 7580 |
28.70 |
| 2026-08-03 12:00 |
01:37:14.67 |
-09:53:08.8 |
HIP 7580 |
29.45 |
| 2026-08-04 00:00 |
01:37:13.79 |
-09:53:52.6 |
HIP 7611 |
29.31 |
| 2026-08-04 12:00 |
01:37:12.87 |
-09:54:36.7 |
HIP 7611 |
28.75 |
| 2026-08-05 00:00 |
01:37:11.90 |
-09:55:20.9 |
HIP 7611 |
28.20 |
| 2026-08-05 12:00 |
01:37:10.88 |
-09:56:05.4 |
HIP 7611 |
27.66 |
| 2026-08-06 00:00 |
01:37:09.81 |
-09:56:50.0 |
HIP 7611 |
27.14 |
| 2026-08-06 12:00 |
01:37:08.69 |
-09:57:34.9 |
HIP 7611 |
26.63 |
| 2026-08-07 00:00 |
01:37:07.53 |
-09:58:20.0 |
HIP 7611 |
26.14 |
| 2026-08-07 12:00 |
01:37:06.31 |
-09:59:05.2 |
HIP 7611 |
25.68 |
| 2026-08-08 00:00 |
01:37:05.05 |
-09:59:50.7 |
HIP 7611 |
25.23 |
| 2026-08-08 12:00 |
01:37:03.74 |
-10:00:36.4 |
HIP 7611 |
24.81 |
| 2026-08-09 00:00 |
01:37:02.38 |
-10:01:22.2 |
HIP 7611 |
24.41 |
| 2026-08-09 12:00 |
01:37:00.97 |
-10:02:08.2 |
HIP 7611 |
24.04 |
| 2026-08-10 00:00 |
01:36:59.51 |
-10:02:54.4 |
HIP 7611 |
23.70 |
| 2026-08-10 12:00 |
01:36:58.01 |
-10:03:40.8 |
HIP 7611 |
23.39 |
| 2026-08-11 00:00 |
01:36:56.45 |
-10:04:27.4 |
HIP 7611 |
23.12 |
| 2026-08-11 12:00 |
01:36:54.85 |
-10:05:14.2 |
HIP 7611 |
22.88 |
| 2026-08-12 00:00 |
01:36:53.20 |
-10:06:01.1 |
HIP 7611 |
22.69 |
| 2026-08-12 12:00 |
01:36:51.51 |
-10:06:48.2 |
HIP 7611 |
22.53 |
| 2026-08-13 00:00 |
01:36:49.76 |
-10:07:35.4 |
HIP 7611 |
22.41 |
| 2026-08-13 12:00 |
01:36:47.97 |
-10:08:22.8 |
HIP 7611 |
22.34 |
| 2026-08-14 00:00 |
01:36:46.13 |
-10:09:10.4 |
HIP 7611 |
22.31 |
| 2026-08-14 12:00 |
01:36:44.25 |
-10:09:58.1 |
HIP 7611 |
22.33 |
| 2026-08-15 00:00 |
01:36:42.31 |
-10:10:46.0 |
HIP 7611 |
22.40 |
| 2026-08-15 12:00 |
01:36:40.33 |
-10:11:34.0 |
HIP 7611 |
22.51 |
| 2026-08-16 00:00 |
01:36:38.31 |
-10:12:22.1 |
HIP 7611 |
22.68 |
| 2026-08-16 12:00 |
01:36:36.23 |
-10:13:10.4 |
HIP 7611 |
22.89 |
| 2026-08-17 00:00 |
01:36:34.11 |
-10:13:58.8 |
HIP 7611 |
23.15 |
| 2026-08-17 12:00 |
01:36:31.95 |
-10:14:47.4 |
HIP 7611 |
23.45 |
| 2026-08-18 00:00 |
01:36:29.74 |
-10:15:36.1 |
HIP 7611 |
23.80 |
| 2026-08-18 12:00 |
01:36:27.48 |
-10:16:24.9 |
HIP 7611 |
24.20 |
| 2026-08-19 00:00 |
01:36:25.18 |
-10:17:13.8 |
HIP 7611 |
24.64 |