| Parameter |
Value |
| Designation |
C/2011 Q2 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2012-01-19T18:55:25.829760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:55Z |
| Obs used |
106 |
| NEO |
- |
| M1 |
4.700 |
| K1 |
23.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-09-16.0000000 |
| e |
1.00007496 |
| q (au) |
1.349561 |
| a (au) |
-18003.301883 |
| i (deg) |
36.866576 |
| Ω (om, deg) |
287.369526 |
| ω (w, deg) |
34.628570 |
| M (ma, deg) |
-0.000051 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.734 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.734 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.502 |
| k |
1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
07:40:31.73 |
+14:40:24.2 |
HIP 37282 |
21.39 |
| 2026-05-12 12:00 |
07:40:33.58 |
+14:40:23.5 |
HIP 37282 |
21.75 |
| 2026-05-13 00:00 |
07:40:35.46 |
+14:40:22.8 |
HIP 37282 |
22.11 |
| 2026-05-13 12:00 |
07:40:37.37 |
+14:40:22.0 |
HIP 37282 |
22.49 |
| 2026-05-14 00:00 |
07:40:39.30 |
+14:40:21.1 |
HIP 37282 |
22.87 |
| 2026-05-14 12:00 |
07:40:41.26 |
+14:40:20.1 |
HIP 37282 |
23.25 |
| 2026-05-15 00:00 |
07:40:43.24 |
+14:40:19.0 |
HIP 37282 |
23.65 |
| 2026-05-15 12:00 |
07:40:45.26 |
+14:40:17.8 |
HIP 37282 |
24.05 |
| 2026-05-16 00:00 |
07:40:47.29 |
+14:40:16.5 |
HIP 37282 |
24.47 |
| 2026-05-16 12:00 |
07:40:49.36 |
+14:40:15.1 |
HIP 37282 |
24.89 |
| 2026-05-17 00:00 |
07:40:51.44 |
+14:40:13.6 |
HIP 37282 |
25.31 |
| 2026-05-17 12:00 |
07:40:53.56 |
+14:40:12.0 |
HIP 37282 |
25.75 |
| 2026-05-18 00:00 |
07:40:55.70 |
+14:40:10.3 |
HIP 37282 |
26.19 |
| 2026-05-18 12:00 |
07:40:57.86 |
+14:40:08.6 |
HIP 37282 |
26.64 |
| 2026-05-19 00:00 |
07:41:00.05 |
+14:40:06.7 |
HIP 37282 |
27.09 |
| 2026-05-19 12:00 |
07:41:02.26 |
+14:40:04.7 |
HIP 37282 |
27.56 |
| 2026-05-20 00:00 |
07:41:04.50 |
+14:40:02.7 |
HIP 37282 |
28.03 |
| 2026-05-20 12:00 |
07:41:06.77 |
+14:40:00.5 |
HIP 37282 |
28.51 |
| 2026-05-21 00:00 |
07:41:09.05 |
+14:39:58.3 |
HIP 37282 |
28.99 |
| 2026-05-21 12:00 |
07:41:11.36 |
+14:39:55.9 |
HIP 37282 |
29.48 |
| 2026-05-22 00:00 |
07:41:13.70 |
+14:39:53.5 |
HIP 37521 |
29.89 |
| 2026-05-22 12:00 |
07:41:16.06 |
+14:39:50.9 |
HIP 37521 |
29.63 |
| 2026-05-23 00:00 |
07:41:18.44 |
+14:39:48.3 |
HIP 37521 |
29.37 |
| 2026-05-23 12:00 |
07:41:20.84 |
+14:39:45.6 |
HIP 37521 |
29.12 |
| 2026-05-24 00:00 |
07:41:23.27 |
+14:39:42.8 |
HIP 37521 |
28.87 |
| 2026-05-24 12:00 |
07:41:25.72 |
+14:39:39.8 |
HIP 37521 |
28.63 |
| 2026-05-25 00:00 |
07:41:28.20 |
+14:39:36.8 |
HIP 37521 |
28.40 |
| 2026-05-25 12:00 |
07:41:30.69 |
+14:39:33.7 |
HIP 37521 |
28.17 |
| 2026-05-26 00:00 |
07:41:33.21 |
+14:39:30.5 |
HIP 37521 |
27.96 |
| 2026-05-26 12:00 |
07:41:35.75 |
+14:39:27.2 |
HIP 37521 |
27.75 |
| 2026-05-27 00:00 |
07:41:38.31 |
+14:39:23.9 |
HIP 37521 |
27.55 |
| 2026-05-27 12:00 |
07:41:40.89 |
+14:39:20.4 |
HIP 37521 |
27.37 |
| 2026-05-28 00:00 |
07:41:43.50 |
+14:39:16.8 |
HIP 37521 |
27.19 |
| 2026-05-28 12:00 |
07:41:46.12 |
+14:39:13.2 |
HIP 37521 |
27.03 |
| 2026-05-29 00:00 |
07:41:48.77 |
+14:39:09.4 |
HIP 37521 |
26.87 |
| 2026-05-29 12:00 |
07:41:51.44 |
+14:39:05.6 |
HIP 37521 |
26.73 |
| 2026-05-30 00:00 |
07:41:54.13 |
+14:39:01.6 |
HIP 37521 |
26.61 |
| 2026-05-30 12:00 |
07:41:56.84 |
+14:38:57.6 |
HIP 37521 |
26.49 |
| 2026-05-31 00:00 |
07:41:59.57 |
+14:38:53.5 |
HIP 37521 |
26.39 |
| 2026-05-31 12:00 |
07:42:02.32 |
+14:38:49.2 |
HIP 37521 |
26.31 |
| 2026-06-01 00:00 |
07:42:05.09 |
+14:38:44.9 |
HIP 37521 |
26.24 |
| 2026-06-01 12:00 |
07:42:07.87 |
+14:38:40.5 |
HIP 37521 |
26.19 |
| 2026-06-02 00:00 |
07:42:10.68 |
+14:38:36.0 |
HIP 37521 |
26.15 |