P/2012 O1 (McNaught)
| 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
$$
M_a = (17.186 + 4.987\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.186 |
| n |
4.987 |
| gf |
0.997 |
| 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) |
| 2026-02-03 00:00 |
00:20:29.91 |
-03:28:20.0 |
HIP 1691 |
14.45 |
| 2026-02-03 12:00 |
00:21:45.46 |
-03:19:03.1 |
HIP 1691 |
8.08 |
| 2026-02-04 00:00 |
00:23:00.85 |
-03:09:47.5 |
HIP 1873 |
11.60 |
| 2026-02-04 12:00 |
00:24:16.08 |
-03:00:33.1 |
HIP 1873 |
9.51 |
| 2026-02-05 00:00 |
00:25:31.16 |
-02:51:20.0 |
HIP 1873 |
30.33 |
| 2026-02-05 12:00 |
00:26:46.09 |
-02:42:08.2 |
HIP 2242 |
27.95 |
| 2026-02-06 00:00 |
00:28:00.86 |
-02:32:57.7 |
HIP 2242 |
7.20 |
| 2026-02-06 12:00 |
00:29:15.48 |
-02:23:48.5 |
HIP 2242 |
13.69 |
| 2026-02-07 00:00 |
00:30:29.96 |
-02:14:40.7 |
HIP 2471 |
19.18 |
| 2026-02-07 12:00 |
00:31:44.28 |
-02:05:34.2 |
HIP 2471 |
6.80 |
| 2026-02-08 00:00 |
00:32:58.46 |
-01:56:29.0 |
HIP 2496 |
21.35 |
| 2026-02-08 12:00 |
00:34:12.49 |
-01:47:25.3 |
HIP 2786 |
25.98 |
| 2026-02-09 00:00 |
00:35:26.37 |
-01:38:22.9 |
HIP 2735 |
21.18 |
| 2026-02-09 12:00 |
00:36:40.12 |
-01:29:21.9 |
HIP 2735 |
28.16 |
| 2026-02-10 00:00 |
00:37:53.72 |
-01:20:22.3 |
HIP 3072 |
19.42 |
| 2026-02-10 12:00 |
00:39:07.18 |
-01:11:24.2 |
HIP 3072 |
2.57 |
| 2026-02-11 00:00 |
00:40:20.50 |
-01:02:27.5 |
HIP 3072 |
21.66 |
| 2026-02-11 12:00 |
00:41:33.69 |
-00:53:32.2 |
HIP 3264 |
24.44 |
| 2026-02-12 00:00 |
00:42:46.73 |
-00:44:38.4 |
HIP 3410 |
13.08 |
| 2026-02-12 12:00 |
00:43:59.64 |
-00:35:46.1 |
HIP 3410 |
19.90 |
| 2026-02-13 00:00 |
00:45:12.42 |
-00:26:55.3 |
HIP 3410 |
37.94 |
| 2026-02-13 12:00 |
00:46:25.06 |
-00:18:05.9 |
HIP 3738 |
24.12 |
| 2026-02-14 00:00 |
00:47:37.57 |
-00:09:18.1 |
HIP 3738 |
7.76 |
| 2026-02-14 12:00 |
00:48:49.95 |
-00:00:31.8 |
HIP 3738 |
18.69 |
| 2026-02-15 00:00 |
00:50:02.20 |
+00:08:13.0 |
HIP 3947 |
16.09 |
| 2026-02-15 12:00 |
00:51:14.32 |
+00:16:56.2 |
HIP 3947 |
23.39 |
| 2026-02-16 00:00 |
00:52:26.31 |
+00:25:37.9 |
HIP 4007 |
32.64 |
| 2026-02-16 12:00 |
00:53:38.17 |
+00:34:18.0 |
HIP 4297 |
24.58 |
| 2026-02-17 00:00 |
00:54:49.91 |
+00:42:56.6 |
HIP 4297 |
5.29 |
| 2026-02-17 12:00 |
00:56:01.52 |
+00:51:33.5 |
HIP 4312 |
13.12 |
| 2026-02-18 00:00 |
00:57:13.01 |
+01:00:08.9 |
HIP 4465 |
21.70 |
| 2026-02-18 12:00 |
00:58:24.37 |
+01:08:42.6 |
HIP 4465 |
21.91 |
| 2026-02-19 00:00 |
00:59:35.61 |
+01:17:14.8 |
HIP 4623 |
30.26 |
| 2026-02-19 12:00 |
01:00:46.73 |
+01:25:45.3 |
HIP 4623 |
43.96 |
| 2026-02-20 00:00 |
01:01:57.73 |
+01:34:14.1 |
HIP 4979 |
30.36 |
| 2026-02-20 12:00 |
01:03:08.61 |
+01:42:41.3 |
HIP 4979 |
23.00 |
| 2026-02-21 00:00 |
01:04:19.36 |
+01:51:06.9 |
HIP 5064 |
17.42 |
| 2026-02-21 12:00 |
01:05:30.00 |
+01:59:30.7 |
HIP 5163 |
19.22 |
| 2026-02-22 00:00 |
01:06:40.52 |
+02:07:52.9 |
HIP 5315 |
21.40 |
| 2026-02-22 12:00 |
01:07:50.93 |
+02:16:13.4 |
HIP 5315 |
16.72 |
| 2026-02-23 00:00 |
01:09:01.21 |
+02:24:32.2 |
HIP 5413 |
9.03 |
| 2026-02-23 12:00 |
01:10:11.38 |
+02:32:49.3 |
HIP 5510 |
8.22 |
| 2026-02-24 00:00 |
01:11:21.43 |
+02:41:04.6 |
HIP 5510 |
18.67 |