C/2009 K5 (McNaught)
| Parameter |
Value |
| Designation |
C/2009 K5 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2010-04-30T00:35:23.349120Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:31Z |
| Obs used |
2488 |
| NEO |
- |
| M1 |
11.900 |
| K1 |
5.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2010-07-13.0000000 |
| e |
1.00083854 |
| q (au) |
1.422401 |
| a (au) |
-1696.276803 |
| i (deg) |
103.879390 |
| Ω (om, deg) |
257.856328 |
| ω (w, deg) |
66.174175 |
| M (ma, deg) |
0.001044 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.367 + 4.423\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.367 |
| n |
4.423 |
| gf |
0.990 |
| gb |
-0.589 |
| k |
0.800 |
| δ90 |
10.000 |
| Parameter |
Symbol |
Range |
Description |
| Absolute magnitude at 1 AU from Sun and Earth |
H0 |
-5 to 20 |
Intrinsic brightness of the comet |
| Photometric slope parameter |
n |
2 to 6 |
Rate of brightness change with heliocentric distance |
| Forward scattering asymmetry factor |
gf |
0.8 to 1 |
Degree of forward scattering |
| Backward scattering asymmetry factor |
gb |
-1 to -0.5 |
Degree of backward scattering |
| Partitioning coefficient |
k |
0.8 to 1 |
Ratio between forward/backward scattering contributions |
| Dust-to-gas brightness ratio |
δ90 |
1 to 10 |
Relative contribution of dust scattering to gas emission |
Reference: EPSC-DPS2025-160
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2009-05-27 |
2010-04-29 |
-0.0143 |
-1.624 |
| 2010-04-30 |
2010-09-19 |
+0.7531 |
-1.983 |
| 2010-09-19 |
2010-10-18 |
+22.8171 |
-10.034 |
| 2010-10-18 |
2011-11-26 |
-2.0491 |
+1.114 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
04:35:56.76 |
-19:53:33.1 |
HIP 21418 |
7.52 |
| 2026-02-03 12:00 |
04:35:55.05 |
-19:53:06.3 |
HIP 21418 |
7.89 |
| 2026-02-04 00:00 |
04:35:53.37 |
-19:52:39.4 |
HIP 21418 |
8.29 |
| 2026-02-04 12:00 |
04:35:51.72 |
-19:52:12.3 |
HIP 21418 |
8.71 |
| 2026-02-05 00:00 |
04:35:50.11 |
-19:51:45.0 |
HIP 21418 |
9.16 |
| 2026-02-05 12:00 |
04:35:48.52 |
-19:51:17.6 |
HIP 21418 |
9.62 |
| 2026-02-06 00:00 |
04:35:46.96 |
-19:50:50.0 |
HIP 21418 |
10.10 |
| 2026-02-06 12:00 |
04:35:45.43 |
-19:50:22.2 |
HIP 21418 |
10.59 |
| 2026-02-07 00:00 |
04:35:43.94 |
-19:49:54.3 |
HIP 21418 |
11.09 |
| 2026-02-07 12:00 |
04:35:42.47 |
-19:49:26.2 |
HIP 21363 |
11.44 |
| 2026-02-08 00:00 |
04:35:41.04 |
-19:48:58.0 |
HIP 21363 |
11.41 |
| 2026-02-08 12:00 |
04:35:39.64 |
-19:48:29.7 |
HIP 21363 |
11.41 |
| 2026-02-09 00:00 |
04:35:38.27 |
-19:48:01.2 |
HIP 21363 |
11.45 |
| 2026-02-09 12:00 |
04:35:36.93 |
-19:47:32.5 |
HIP 21363 |
11.52 |
| 2026-02-10 00:00 |
04:35:35.62 |
-19:47:03.7 |
HIP 21363 |
11.63 |
| 2026-02-10 12:00 |
04:35:34.34 |
-19:46:34.8 |
HIP 21363 |
11.77 |
| 2026-02-11 00:00 |
04:35:33.09 |
-19:46:05.7 |
HIP 21363 |
11.95 |
| 2026-02-11 12:00 |
04:35:31.88 |
-19:45:36.6 |
HIP 21363 |
12.15 |
| 2026-02-12 00:00 |
04:35:30.69 |
-19:45:07.2 |
HIP 21363 |
12.38 |
| 2026-02-12 12:00 |
04:35:29.54 |
-19:44:37.8 |
HIP 21363 |
12.64 |
| 2026-02-13 00:00 |
04:35:28.42 |
-19:44:08.2 |
HIP 21363 |
12.93 |
| 2026-02-13 12:00 |
04:35:27.33 |
-19:43:38.5 |
HIP 21363 |
13.23 |
| 2026-02-14 00:00 |
04:35:26.28 |
-19:43:08.7 |
HIP 21363 |
13.56 |
| 2026-02-14 12:00 |
04:35:25.25 |
-19:42:38.7 |
HIP 21363 |
13.91 |
| 2026-02-15 00:00 |
04:35:24.26 |
-19:42:08.7 |
HIP 21363 |
14.27 |
| 2026-02-15 12:00 |
04:35:23.30 |
-19:41:38.5 |
HIP 21363 |
14.65 |
| 2026-02-16 00:00 |
04:35:22.37 |
-19:41:08.2 |
HIP 21363 |
15.05 |
| 2026-02-16 12:00 |
04:35:21.48 |
-19:40:37.9 |
HIP 21363 |
15.46 |
| 2026-02-17 00:00 |
04:35:20.61 |
-19:40:07.4 |
HIP 21363 |
15.88 |
| 2026-02-17 12:00 |
04:35:19.78 |
-19:39:36.8 |
HIP 21363 |
16.31 |
| 2026-02-18 00:00 |
04:35:18.98 |
-19:39:06.1 |
HIP 21363 |
16.75 |
| 2026-02-18 12:00 |
04:35:18.22 |
-19:38:35.3 |
HIP 21363 |
17.21 |
| 2026-02-19 00:00 |
04:35:17.48 |
-19:38:04.5 |
HIP 21363 |
17.67 |
| 2026-02-19 12:00 |
04:35:16.78 |
-19:37:33.5 |
HIP 21363 |
18.13 |
| 2026-02-20 00:00 |
04:35:16.11 |
-19:37:02.5 |
HIP 21363 |
18.61 |
| 2026-02-20 12:00 |
04:35:15.47 |
-19:36:31.4 |
HIP 21363 |
19.09 |
| 2026-02-21 00:00 |
04:35:14.86 |
-19:36:00.2 |
HIP 21363 |
19.58 |
| 2026-02-21 12:00 |
04:35:14.29 |
-19:35:28.9 |
HIP 21363 |
20.07 |
| 2026-02-22 00:00 |
04:35:13.75 |
-19:34:57.5 |
HIP 21363 |
20.56 |
| 2026-02-22 12:00 |
04:35:13.24 |
-19:34:26.1 |
HIP 21363 |
21.07 |
| 2026-02-23 00:00 |
04:35:12.77 |
-19:33:54.6 |
HIP 21363 |
21.57 |
| 2026-02-23 12:00 |
04:35:12.32 |
-19:33:23.1 |
HIP 21409 |
21.29 |
| 2026-02-24 00:00 |
04:35:11.91 |
-19:32:51.4 |
HIP 21409 |
20.83 |