| Parameter |
Value |
| Designation |
262P/McNaught-Russell |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-12-04T11:01:48.411840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:28:09Z |
| Obs used |
1339 |
| NEO |
Yes |
| M1 |
14.700 |
| K1 |
6.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-12-24.0000000 |
| e |
0.81540093 |
| q (au) |
1.280260 |
| a (au) |
6.935353 |
| i (deg) |
29.079418 |
| Ω (om, deg) |
218.014306 |
| ω (w, deg) |
171.169762 |
| M (ma, deg) |
341.303779 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.572 + 3.736\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.572 |
| n |
3.736 |
| gf |
0.800 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
1.000 |
| 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 |
| 2012-05-29 |
2012-09-20 |
-8.5325 |
+2.913 |
| 2012-09-20 |
2012-12-04 |
+11.6281 |
-1.021 |
| 2012-12-05 |
2013-04-22 |
-6.0909 |
-0.588 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
14:47:25.79 |
-11:08:12.4 |
HIP 72299 |
14.80 |
| 2026-09-20 12:00 |
14:47:34.75 |
-11:08:50.8 |
HIP 72299 |
15.10 |
| 2026-09-21 00:00 |
14:47:43.77 |
-11:09:29.5 |
HIP 72299 |
15.74 |
| 2026-09-21 12:00 |
14:47:52.85 |
-11:10:08.3 |
HIP 72299 |
16.69 |
| 2026-09-22 00:00 |
14:48:01.99 |
-11:10:47.3 |
HIP 72299 |
17.89 |
| 2026-09-22 12:00 |
14:48:11.19 |
-11:11:26.5 |
HIP 72299 |
19.32 |
| 2026-09-23 00:00 |
14:48:20.44 |
-11:12:05.8 |
HIP 72299 |
20.92 |
| 2026-09-23 12:00 |
14:48:29.76 |
-11:12:45.3 |
HIP 72299 |
22.67 |
| 2026-09-24 00:00 |
14:48:39.13 |
-11:13:24.9 |
HIP 72299 |
24.54 |
| 2026-09-24 12:00 |
14:48:48.56 |
-11:14:04.7 |
HIP 72478 |
25.05 |
| 2026-09-25 00:00 |
14:48:58.04 |
-11:14:44.6 |
HIP 72478 |
25.31 |
| 2026-09-25 12:00 |
14:49:07.58 |
-11:15:24.7 |
HIP 72478 |
25.79 |
| 2026-09-26 00:00 |
14:49:17.18 |
-11:16:04.9 |
HIP 72478 |
26.49 |
| 2026-09-26 12:00 |
14:49:26.83 |
-11:16:45.2 |
HIP 72478 |
27.40 |
| 2026-09-27 00:00 |
14:49:36.54 |
-11:17:25.7 |
HIP 72478 |
28.50 |
| 2026-09-27 12:00 |
14:49:46.30 |
-11:18:06.3 |
HIP 72478 |
29.77 |
| 2026-09-28 00:00 |
14:49:56.12 |
-11:18:47.0 |
HIP 72478 |
31.19 |
| 2026-09-28 12:00 |
14:50:05.99 |
-11:19:27.9 |
HIP 72478 |
32.75 |
| 2026-09-29 00:00 |
14:50:15.91 |
-11:20:08.9 |
HIP 72750 |
31.76 |
| 2026-09-29 12:00 |
14:50:25.88 |
-11:20:50.0 |
HIP 72750 |
29.22 |
| 2026-09-30 00:00 |
14:50:35.91 |
-11:21:31.2 |
HIP 72750 |
26.67 |
| 2026-09-30 12:00 |
14:50:45.99 |
-11:22:12.6 |
HIP 72750 |
24.10 |
| 2026-10-01 00:00 |
14:50:56.12 |
-11:22:54.0 |
HIP 72750 |
21.53 |
| 2026-10-01 12:00 |
14:51:06.30 |
-11:23:35.6 |
HIP 72750 |
18.94 |
| 2026-10-02 00:00 |
14:51:16.54 |
-11:24:17.3 |
HIP 72750 |
16.33 |
| 2026-10-02 12:00 |
14:51:26.82 |
-11:24:59.1 |
HIP 72750 |
13.72 |
| 2026-10-03 00:00 |
14:51:37.15 |
-11:25:40.9 |
HIP 72750 |
11.09 |
| 2026-10-03 12:00 |
14:51:47.53 |
-11:26:22.9 |
HIP 72750 |
8.46 |
| 2026-10-04 00:00 |
14:51:57.97 |
-11:27:05.0 |
HIP 72750 |
5.81 |
| 2026-10-04 12:00 |
14:52:08.45 |
-11:27:47.1 |
HIP 72750 |
3.15 |
| 2026-10-05 00:00 |
14:52:18.97 |
-11:28:29.4 |
HIP 72750 |
0.53 |
| 2026-10-05 12:00 |
14:52:29.55 |
-11:29:11.7 |
HIP 72750 |
2.23 |
| 2026-10-06 00:00 |
14:52:40.17 |
-11:29:54.1 |
HIP 72750 |
4.92 |
| 2026-10-06 12:00 |
14:52:50.84 |
-11:30:36.6 |
HIP 72750 |
7.63 |
| 2026-10-07 00:00 |
14:53:01.55 |
-11:31:19.2 |
HIP 72750 |
10.34 |
| 2026-10-07 12:00 |
14:53:12.31 |
-11:32:01.8 |
HIP 72750 |
13.07 |
| 2026-10-08 00:00 |
14:53:23.12 |
-11:32:44.5 |
HIP 72919 |
13.79 |
| 2026-10-08 12:00 |
14:53:33.97 |
-11:33:27.2 |
HIP 72919 |
11.21 |
| 2026-10-09 00:00 |
14:53:44.86 |
-11:34:10.1 |
HIP 72919 |
8.73 |
| 2026-10-09 12:00 |
14:53:55.80 |
-11:34:52.9 |
HIP 72919 |
6.47 |
| 2026-10-10 00:00 |
14:54:06.78 |
-11:35:35.9 |
HIP 72919 |
4.79 |
| 2026-10-10 12:00 |
14:54:17.80 |
-11:36:18.9 |
HIP 72919 |
4.42 |
| 2026-10-11 00:00 |
14:54:28.86 |
-11:37:01.9 |
HIP 72919 |
5.64 |