| Parameter |
Value |
| Designation |
P/2012 O1 (McNaught) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-07-23T21:45:24.840000Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:19Z |
| Obs used |
98 |
| NEO |
- |
| M1 |
18.900 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-08-23.0000000 |
| e |
0.57924394 |
| q (au) |
1.499146 |
| a (au) |
3.562980 |
| i (deg) |
11.428578 |
| Ω (om, deg) |
111.278961 |
| ω (w, deg) |
222.109887 |
| M (ma, deg) |
4.410178 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.186 + 4.986\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.186 |
| n |
4.986 |
| gf |
1.000 |
| gb |
-0.758 |
| k |
0.973 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
04:32:09.90 |
+19:49:03.9 |
HIP 21240 |
17.23 |
| 2026-06-01 12:00 |
04:33:05.11 |
+19:51:34.0 |
HIP 21240 |
5.05 |
| 2026-06-02 00:00 |
04:34:00.24 |
+19:54:02.5 |
HIP 21240 |
10.16 |
| 2026-06-02 12:00 |
04:34:55.29 |
+19:56:29.6 |
HIP 21403 |
10.64 |
| 2026-06-03 00:00 |
04:35:50.27 |
+19:58:55.3 |
HIP 21403 |
2.53 |
| 2026-06-03 12:00 |
04:36:45.17 |
+20:01:19.4 |
HIP 21403 |
15.64 |
| 2026-06-04 00:00 |
04:37:39.99 |
+20:03:42.1 |
HIP 21465 |
23.73 |
| 2026-06-04 12:00 |
04:38:34.74 |
+20:06:03.4 |
HIP 21465 |
34.84 |
| 2026-06-05 00:00 |
04:39:29.40 |
+20:08:23.1 |
HIP 21748 |
26.26 |
| 2026-06-05 12:00 |
04:40:23.99 |
+20:10:41.5 |
HIP 21748 |
22.46 |
| 2026-06-06 00:00 |
04:41:18.50 |
+20:12:58.4 |
HIP 21748 |
25.64 |
| 2026-06-06 12:00 |
04:42:12.93 |
+20:15:13.8 |
HIP 21953 |
25.80 |
| 2026-06-07 00:00 |
04:43:07.27 |
+20:17:27.8 |
HIP 22026 |
13.99 |
| 2026-06-07 12:00 |
04:44:01.54 |
+20:19:40.4 |
HIP 22026 |
1.54 |
| 2026-06-08 00:00 |
04:44:55.73 |
+20:21:51.5 |
HIP 22026 |
11.92 |
| 2026-06-08 12:00 |
04:45:49.84 |
+20:24:01.3 |
HIP 22026 |
24.75 |
| 2026-06-09 00:00 |
04:46:43.87 |
+20:26:09.6 |
HIP 22356 |
28.76 |
| 2026-06-09 12:00 |
04:47:37.82 |
+20:28:16.5 |
HIP 22356 |
17.11 |
| 2026-06-10 00:00 |
04:48:31.69 |
+20:30:22.0 |
HIP 22356 |
9.33 |
| 2026-06-10 12:00 |
04:49:25.47 |
+20:32:26.1 |
HIP 22356 |
14.41 |
| 2026-06-11 00:00 |
04:50:19.17 |
+20:34:28.9 |
HIP 22356 |
25.55 |
| 2026-06-11 12:00 |
04:51:12.79 |
+20:36:30.2 |
HIP 22672 |
35.86 |
| 2026-06-12 00:00 |
04:52:06.33 |
+20:38:30.1 |
HIP 22672 |
32.92 |
| 2026-06-12 12:00 |
04:52:59.78 |
+20:40:28.7 |
HIP 22672 |
34.67 |
| 2026-06-13 00:00 |
04:53:53.15 |
+20:42:25.9 |
HIP 22827 |
26.43 |
| 2026-06-13 12:00 |
04:54:46.43 |
+20:44:21.7 |
HIP 22827 |
21.63 |
| 2026-06-14 00:00 |
04:55:39.63 |
+20:46:16.1 |
HIP 22827 |
23.55 |
| 2026-06-14 12:00 |
04:56:32.74 |
+20:48:09.2 |
HIP 22827 |
30.94 |
| 2026-06-15 00:00 |
04:57:25.77 |
+20:50:01.0 |
HIP 23082 |
32.42 |
| 2026-06-15 12:00 |
04:58:18.71 |
+20:51:51.4 |
HIP 23253 |
27.17 |
| 2026-06-16 00:00 |
04:59:11.56 |
+20:53:40.4 |
HIP 23253 |
14.69 |
| 2026-06-16 12:00 |
05:00:04.32 |
+20:55:28.1 |
HIP 23253 |
2.24 |
| 2026-06-17 00:00 |
05:00:56.99 |
+20:57:14.5 |
HIP 23253 |
10.19 |
| 2026-06-17 12:00 |
05:01:49.58 |
+20:58:59.5 |
HIP 23396 |
9.27 |
| 2026-06-18 00:00 |
05:02:42.07 |
+21:00:43.3 |
HIP 23396 |
17.36 |
| 2026-06-18 12:00 |
05:03:34.47 |
+21:02:25.7 |
HIP 23589 |
17.99 |
| 2026-06-19 00:00 |
05:04:26.78 |
+21:04:06.8 |
HIP 23589 |
12.62 |
| 2026-06-19 12:00 |
05:05:19.00 |
+21:05:46.6 |
HIP 23589 |
17.26 |
| 2026-06-20 00:00 |
05:06:11.13 |
+21:07:25.1 |
HIP 23589 |
27.16 |
| 2026-06-20 12:00 |
05:07:03.16 |
+21:09:02.4 |
HIP 23946 |
31.76 |
| 2026-06-21 00:00 |
05:07:55.10 |
+21:10:38.3 |
HIP 23946 |
22.56 |
| 2026-06-21 12:00 |
05:08:46.95 |
+21:12:13.0 |
HIP 23946 |
17.52 |
| 2026-06-22 00:00 |
05:09:38.71 |
+21:13:46.4 |
HIP 23946 |
20.05 |