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 · 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) |
| 2026-05-12 00:00 |
01:29:11.28 |
-09:03:27.6 |
HIP 6964 |
17.94 |
| 2026-05-12 12:00 |
01:29:17.09 |
-09:03:16.7 |
HIP 6964 |
17.25 |
| 2026-05-13 00:00 |
01:29:22.88 |
-09:03:06.1 |
HIP 6964 |
16.67 |
| 2026-05-13 12:00 |
01:29:28.64 |
-09:02:55.9 |
HIP 6964 |
16.20 |
| 2026-05-14 00:00 |
01:29:34.38 |
-09:02:46.0 |
HIP 6964 |
15.85 |
| 2026-05-14 12:00 |
01:29:40.10 |
-09:02:36.4 |
HIP 6964 |
15.63 |
| 2026-05-15 00:00 |
01:29:45.80 |
-09:02:27.2 |
HIP 6964 |
15.54 |
| 2026-05-15 12:00 |
01:29:51.48 |
-09:02:18.3 |
HIP 6964 |
15.59 |
| 2026-05-16 00:00 |
01:29:57.13 |
-09:02:09.7 |
HIP 6964 |
15.77 |
| 2026-05-16 12:00 |
01:30:02.76 |
-09:02:01.5 |
HIP 6964 |
16.07 |
| 2026-05-17 00:00 |
01:30:08.37 |
-09:01:53.7 |
HIP 6964 |
16.49 |
| 2026-05-17 12:00 |
01:30:13.95 |
-09:01:46.1 |
HIP 6964 |
17.01 |
| 2026-05-18 00:00 |
01:30:19.50 |
-09:01:39.0 |
HIP 6964 |
17.63 |
| 2026-05-18 12:00 |
01:30:25.04 |
-09:01:32.1 |
HIP 6964 |
18.33 |
| 2026-05-19 00:00 |
01:30:30.54 |
-09:01:25.6 |
HIP 6964 |
19.11 |
| 2026-05-19 12:00 |
01:30:36.03 |
-09:01:19.5 |
HIP 7076 |
19.42 |
| 2026-05-20 00:00 |
01:30:41.48 |
-09:01:13.7 |
HIP 7076 |
18.95 |
| 2026-05-20 12:00 |
01:30:46.91 |
-09:01:08.2 |
HIP 7076 |
18.57 |
| 2026-05-21 00:00 |
01:30:52.32 |
-09:01:03.1 |
HIP 7076 |
18.26 |
| 2026-05-21 12:00 |
01:30:57.70 |
-09:00:58.4 |
HIP 7076 |
18.05 |
| 2026-05-22 00:00 |
01:31:03.05 |
-09:00:54.0 |
HIP 7076 |
17.93 |
| 2026-05-22 12:00 |
01:31:08.37 |
-09:00:50.0 |
HIP 7076 |
17.90 |
| 2026-05-23 00:00 |
01:31:13.67 |
-09:00:46.3 |
HIP 7076 |
17.96 |
| 2026-05-23 12:00 |
01:31:18.94 |
-09:00:42.9 |
HIP 7076 |
18.11 |
| 2026-05-24 00:00 |
01:31:24.18 |
-09:00:39.9 |
HIP 7076 |
18.35 |
| 2026-05-24 12:00 |
01:31:29.39 |
-09:00:37.3 |
HIP 7076 |
18.66 |
| 2026-05-25 00:00 |
01:31:34.58 |
-09:00:35.0 |
HIP 7076 |
19.05 |
| 2026-05-25 12:00 |
01:31:39.73 |
-09:00:33.0 |
HIP 7076 |
19.51 |
| 2026-05-26 00:00 |
01:31:44.86 |
-09:00:31.4 |
HIP 7222 |
19.42 |
| 2026-05-26 12:00 |
01:31:49.96 |
-09:00:30.2 |
HIP 7222 |
18.16 |
| 2026-05-27 00:00 |
01:31:55.03 |
-09:00:29.3 |
HIP 7222 |
16.91 |
| 2026-05-27 12:00 |
01:32:00.07 |
-09:00:28.8 |
HIP 7222 |
15.67 |
| 2026-05-28 00:00 |
01:32:05.08 |
-09:00:28.6 |
HIP 7222 |
14.43 |
| 2026-05-28 12:00 |
01:32:10.06 |
-09:00:28.8 |
HIP 7222 |
13.21 |
| 2026-05-29 00:00 |
01:32:15.00 |
-09:00:29.4 |
HIP 7222 |
11.98 |
| 2026-05-29 12:00 |
01:32:19.92 |
-09:00:30.2 |
HIP 7222 |
10.77 |
| 2026-05-30 00:00 |
01:32:24.81 |
-09:00:31.5 |
HIP 7222 |
9.56 |
| 2026-05-30 12:00 |
01:32:29.66 |
-09:00:33.1 |
HIP 7222 |
8.36 |
| 2026-05-31 00:00 |
01:32:34.49 |
-09:00:35.1 |
HIP 7222 |
7.17 |
| 2026-05-31 12:00 |
01:32:39.28 |
-09:00:37.4 |
HIP 7222 |
5.99 |
| 2026-06-01 00:00 |
01:32:44.04 |
-09:00:40.1 |
HIP 7222 |
4.81 |
| 2026-06-01 12:00 |
01:32:48.77 |
-09:00:43.1 |
HIP 7222 |
3.64 |
| 2026-06-02 00:00 |
01:32:53.47 |
-09:00:46.5 |
HIP 7222 |
2.48 |