C/2012 K6 (McNaught)

メタデータ

項目
Designation C/2012 K6 (McNaught)
Type C
Perihelion (tp_cal, UTC) 2013-05-21T11:03:28.212480Z
Orbit solution date (soln_date, UTC) 2021-04-15T23:32:10Z
Obs used 1091
NEO -
M1 8.900
K1 7.750
PC 0.030
オスキュレーティング軌道要素
項目
Epoch (epoch_cal, TDB) 2013-12-31.0000000
e 0.99919878
q (au) 3.353032
a (au) 4184.883889
i (deg) 135.215103
Ω (om, deg) 206.898541
ω (w, deg) 338.826785
M (ma, deg) 0.000814

等級

C/2012 K6 (McNaught) · Magnitude (Full range)

散乱 + 全体線形

$$ M_a = (8.021 + 3.183\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta $$ $$ \theta = 180^\circ - \alpha $$ $$ \Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b) $$ $$ \Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1 $$

モデル定数

項目
H0 8.021
n 3.183
gf 0.997
gb -1.000
k 1.000
δ90 9.993
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
2012-04-20 2013-05-20 +12.1573 -6.871
2013-06-02 2014-01-30 -1.7355 +0.738
2014-01-30 2015-04-09 -2.5207 +1.571

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 04:36:47.26 +60:24:49.6 HIP 21571 17.65
2026-03-26 12:00 04:36:50.08 +60:24:12.9 HIP 21571 18.05
2026-03-27 00:00 04:36:52.96 +60:23:36.6 HIP 21571 18.46
2026-03-27 12:00 04:36:55.91 +60:23:00.4 HIP 21544 18.16
2026-03-28 00:00 04:36:58.91 +60:22:24.4 HIP 21544 17.49
2026-03-28 12:00 04:37:01.98 +60:21:48.7 HIP 21544 16.82
2026-03-29 00:00 04:37:05.11 +60:21:13.2 HIP 21544 16.16
2026-03-29 12:00 04:37:08.30 +60:20:37.9 HIP 21544 15.50
2026-03-30 00:00 04:37:11.55 +60:20:02.8 HIP 21544 14.86
2026-03-30 12:00 04:37:14.86 +60:19:28.0 HIP 21544 14.22
2026-03-31 00:00 04:37:18.23 +60:18:53.4 HIP 21544 13.59
2026-03-31 12:00 04:37:21.66 +60:18:19.0 HIP 21544 12.97
2026-04-01 00:00 04:37:25.15 +60:17:44.9 HIP 21544 12.36
2026-04-01 12:00 04:37:28.69 +60:17:11.0 HIP 21544 11.77
2026-04-02 00:00 04:37:32.30 +60:16:37.3 HIP 21544 11.20
2026-04-02 12:00 04:37:35.96 +60:16:03.9 HIP 21544 10.65
2026-04-03 00:00 04:37:39.67 +60:15:30.7 HIP 21544 10.13
2026-04-03 12:00 04:37:43.45 +60:14:57.7 HIP 21544 9.64
2026-04-04 00:00 04:37:47.28 +60:14:25.0 HIP 21544 9.18
2026-04-04 12:00 04:37:51.16 +60:13:52.5 HIP 21544 8.77
2026-04-05 00:00 04:37:55.10 +60:13:20.3 HIP 21544 8.41
2026-04-05 12:00 04:37:59.10 +60:12:48.3 HIP 21544 8.10
2026-04-06 00:00 04:38:03.15 +60:12:16.6 HIP 21544 7.85
2026-04-06 12:00 04:38:07.26 +60:11:45.1 HIP 21544 7.67
2026-04-07 00:00 04:38:11.42 +60:11:13.8 HIP 21544 7.57
2026-04-07 12:00 04:38:15.63 +60:10:42.8 HIP 21544 7.55
2026-04-08 00:00 04:38:19.89 +60:10:12.1 HIP 21544 7.60
2026-04-08 12:00 04:38:24.21 +60:09:41.6 HIP 21544 7.74
2026-04-09 00:00 04:38:28.58 +60:09:11.4 HIP 21544 7.95
2026-04-09 12:00 04:38:33.01 +60:08:41.4 HIP 21544 8.22
2026-04-10 00:00 04:38:37.48 +60:08:11.7 HIP 21544 8.57
2026-04-10 12:00 04:38:42.01 +60:07:42.2 HIP 21544 8.97
2026-04-11 00:00 04:38:46.58 +60:07:13.0 HIP 21544 9.41
2026-04-11 12:00 04:38:51.21 +60:06:44.0 HIP 21544 9.91
2026-04-12 00:00 04:38:55.89 +60:06:15.4 HIP 21544 10.44
2026-04-12 12:00 04:39:00.61 +60:05:46.9 HIP 21544 11.00
2026-04-13 00:00 04:39:05.39 +60:05:18.8 HIP 21544 11.59
2026-04-13 12:00 04:39:10.21 +60:04:50.9 HIP 21544 12.21
2026-04-14 00:00 04:39:15.09 +60:04:23.3 HIP 21544 12.84
2026-04-14 12:00 04:39:20.01 +60:03:55.9 HIP 21544 13.50
2026-04-15 00:00 04:39:24.97 +60:03:28.8 HIP 21544 14.17
2026-04-15 12:00 04:39:29.99 +60:03:02.0 HIP 21544 14.86
2026-04-16 00:00 04:39:35.05 +60:02:35.5 HIP 21544 15.56