| Parameter |
Value |
| Designation |
C/2006 Q1 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-07-03T20:33:15.033600Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:00Z |
| Obs used |
2710 |
| NEO |
- |
| M1 |
9.300 |
| K1 |
4.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2009-02-17.0000000 |
| e |
0.99960042 |
| q (au) |
2.763713 |
| a (au) |
6916.474116 |
| i (deg) |
59.050363 |
| Ω (om, deg) |
199.547074 |
| ω (w, deg) |
344.381853 |
| M (ma, deg) |
0.000391 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.125 + 2.335\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.125 |
| n |
2.335 |
| gf |
0.943 |
| gb |
-0.656 |
| k |
0.906 |
| δ90 |
6.533 |
| 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 |
| 2006-08-20 |
2008-01-29 |
+0.9412 |
-1.227 |
| 2008-01-29 |
2008-07-01 |
-6.8432 |
+2.139 |
| 2008-07-03 |
2009-07-06 |
+2.3103 |
-1.470 |
| 2009-07-06 |
2010-10-17 |
+3.1514 |
-2.364 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
22:18:34.25 |
+33:05:36.8 |
HIP 110027 |
19.27 |
| 2026-07-29 12:00 |
22:18:31.21 |
+33:05:39.1 |
HIP 110027 |
18.68 |
| 2026-07-30 00:00 |
22:18:28.16 |
+33:05:41.1 |
HIP 110027 |
18.09 |
| 2026-07-30 12:00 |
22:18:25.09 |
+33:05:42.7 |
HIP 110027 |
17.50 |
| 2026-07-31 00:00 |
22:18:22.01 |
+33:05:44.1 |
HIP 110027 |
16.90 |
| 2026-07-31 12:00 |
22:18:18.92 |
+33:05:45.1 |
HIP 110027 |
16.31 |
| 2026-08-01 00:00 |
22:18:15.81 |
+33:05:45.9 |
HIP 110027 |
15.71 |
| 2026-08-01 12:00 |
22:18:12.69 |
+33:05:46.3 |
HIP 110027 |
15.12 |
| 2026-08-02 00:00 |
22:18:09.55 |
+33:05:46.4 |
HIP 110027 |
14.53 |
| 2026-08-02 12:00 |
22:18:06.41 |
+33:05:46.2 |
HIP 110027 |
13.93 |
| 2026-08-03 00:00 |
22:18:03.25 |
+33:05:45.7 |
HIP 110027 |
13.34 |
| 2026-08-03 12:00 |
22:18:00.08 |
+33:05:44.9 |
HIP 110027 |
12.75 |
| 2026-08-04 00:00 |
22:17:56.89 |
+33:05:43.8 |
HIP 110027 |
12.17 |
| 2026-08-04 12:00 |
22:17:53.70 |
+33:05:42.3 |
HIP 110027 |
11.59 |
| 2026-08-05 00:00 |
22:17:50.49 |
+33:05:40.6 |
HIP 110027 |
11.01 |
| 2026-08-05 12:00 |
22:17:47.27 |
+33:05:38.5 |
HIP 110027 |
10.44 |
| 2026-08-06 00:00 |
22:17:44.05 |
+33:05:36.1 |
HIP 110027 |
9.87 |
| 2026-08-06 12:00 |
22:17:40.81 |
+33:05:33.4 |
HIP 110027 |
9.32 |
| 2026-08-07 00:00 |
22:17:37.56 |
+33:05:30.4 |
HIP 110027 |
8.78 |
| 2026-08-07 12:00 |
22:17:34.30 |
+33:05:27.1 |
HIP 110027 |
8.26 |
| 2026-08-08 00:00 |
22:17:31.03 |
+33:05:23.4 |
HIP 110027 |
7.76 |
| 2026-08-08 12:00 |
22:17:27.75 |
+33:05:19.5 |
HIP 110027 |
7.28 |
| 2026-08-09 00:00 |
22:17:24.46 |
+33:05:15.2 |
HIP 110027 |
6.83 |
| 2026-08-09 12:00 |
22:17:21.16 |
+33:05:10.6 |
HIP 110027 |
6.42 |
| 2026-08-10 00:00 |
22:17:17.85 |
+33:05:05.7 |
HIP 110027 |
6.06 |
| 2026-08-10 12:00 |
22:17:14.54 |
+33:05:00.5 |
HIP 110027 |
5.75 |
| 2026-08-11 00:00 |
22:17:11.21 |
+33:04:54.9 |
HIP 110027 |
5.51 |
| 2026-08-11 12:00 |
22:17:07.88 |
+33:04:49.1 |
HIP 110027 |
5.35 |
| 2026-08-12 00:00 |
22:17:04.54 |
+33:04:42.9 |
HIP 110027 |
5.27 |
| 2026-08-12 12:00 |
22:17:01.19 |
+33:04:36.4 |
HIP 110027 |
5.28 |
| 2026-08-13 00:00 |
22:16:57.84 |
+33:04:29.6 |
HIP 110027 |
5.38 |
| 2026-08-13 12:00 |
22:16:54.48 |
+33:04:22.5 |
HIP 110027 |
5.57 |
| 2026-08-14 00:00 |
22:16:51.11 |
+33:04:15.1 |
HIP 110027 |
5.83 |
| 2026-08-14 12:00 |
22:16:47.74 |
+33:04:07.4 |
HIP 110027 |
6.17 |
| 2026-08-15 00:00 |
22:16:44.36 |
+33:03:59.3 |
HIP 110027 |
6.56 |
| 2026-08-15 12:00 |
22:16:40.97 |
+33:03:50.9 |
HIP 110027 |
7.01 |
| 2026-08-16 00:00 |
22:16:37.58 |
+33:03:42.3 |
HIP 110027 |
7.49 |
| 2026-08-16 12:00 |
22:16:34.19 |
+33:03:33.3 |
HIP 110027 |
8.01 |
| 2026-08-17 00:00 |
22:16:30.79 |
+33:03:24.0 |
HIP 110027 |
8.56 |
| 2026-08-17 12:00 |
22:16:27.38 |
+33:03:14.4 |
HIP 110027 |
9.14 |
| 2026-08-18 00:00 |
22:16:23.97 |
+33:03:04.4 |
HIP 110027 |
9.73 |
| 2026-08-18 12:00 |
22:16:20.56 |
+33:02:54.2 |
HIP 110027 |
10.34 |
| 2026-08-19 00:00 |
22:16:17.14 |
+33:02:43.7 |
HIP 110027 |
10.96 |