P/2012 O2 (McNaught)
| Parameter |
Value |
| Designation |
P/2012 O2 (McNaught) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-06-25T02:23:11.711040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:20Z |
| Obs used |
81 |
| NEO |
- |
| M1 |
17.300 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2012-07-31.0000000 |
| e |
0.53827101 |
| q (au) |
1.660834 |
| a (au) |
3.596989 |
| i (deg) |
24.527455 |
| Ω (om, deg) |
120.813582 |
| ω (w, deg) |
183.047391 |
| M (ma, deg) |
5.186765 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.976 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.976 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.851 |
| k |
0.800 |
| 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 |
19:18:45.35 |
-14:45:17.1 |
HIP 94807 |
24.08 |
| 2026-02-03 12:00 |
19:20:08.79 |
-14:46:09.8 |
HIP 94970 |
37.97 |
| 2026-02-04 00:00 |
19:21:32.29 |
-14:47:00.4 |
HIP 95266 |
37.59 |
| 2026-02-04 12:00 |
19:22:55.86 |
-14:47:49.0 |
HIP 95266 |
32.29 |
| 2026-02-05 00:00 |
19:24:19.48 |
-14:48:35.6 |
HIP 95488 |
23.00 |
| 2026-02-05 12:00 |
19:25:43.16 |
-14:49:20.2 |
HIP 95557 |
15.41 |
| 2026-02-06 00:00 |
19:27:06.91 |
-14:50:02.7 |
HIP 95557 |
18.84 |
| 2026-02-06 12:00 |
19:28:30.71 |
-14:50:43.2 |
HIP 95755 |
15.46 |
| 2026-02-07 00:00 |
19:29:54.56 |
-14:51:21.6 |
HIP 95974 |
23.35 |
| 2026-02-07 12:00 |
19:31:18.47 |
-14:51:58.1 |
HIP 96105 |
16.13 |
| 2026-02-08 00:00 |
19:32:42.44 |
-14:52:32.6 |
HIP 96105 |
5.65 |
| 2026-02-08 12:00 |
19:34:06.46 |
-14:53:05.0 |
HIP 96169 |
14.40 |
| 2026-02-09 00:00 |
19:35:30.53 |
-14:53:35.4 |
HIP 96169 |
33.38 |
| 2026-02-09 12:00 |
19:36:54.65 |
-14:54:03.9 |
HIP 96557 |
15.31 |
| 2026-02-10 00:00 |
19:38:18.82 |
-14:54:30.3 |
HIP 96557 |
11.29 |
| 2026-02-10 12:00 |
19:39:43.04 |
-14:54:54.8 |
HIP 96738 |
4.76 |
| 2026-02-11 00:00 |
19:41:07.31 |
-14:55:17.2 |
HIP 96738 |
18.23 |
| 2026-02-11 12:00 |
19:42:31.62 |
-14:55:37.7 |
HIP 97063 |
35.81 |
| 2026-02-12 00:00 |
19:43:55.98 |
-14:55:56.2 |
HIP 97190 |
21.43 |
| 2026-02-12 12:00 |
19:45:20.38 |
-14:56:12.8 |
HIP 97190 |
10.55 |
| 2026-02-13 00:00 |
19:46:44.82 |
-14:56:27.3 |
HIP 97190 |
24.40 |
| 2026-02-13 12:00 |
19:48:09.31 |
-14:56:40.0 |
HIP 97422 |
22.70 |
| 2026-02-14 00:00 |
19:49:33.84 |
-14:56:50.6 |
HIP 97614 |
11.79 |
| 2026-02-14 12:00 |
19:50:58.41 |
-14:56:59.4 |
HIP 97614 |
8.69 |
| 2026-02-15 00:00 |
19:52:23.01 |
-14:57:06.2 |
HIP 97736 |
14.46 |
| 2026-02-15 12:00 |
19:53:47.65 |
-14:57:11.1 |
HIP 97849 |
23.25 |
| 2026-02-16 00:00 |
19:55:12.33 |
-14:57:14.0 |
HIP 98075 |
29.04 |
| 2026-02-16 12:00 |
19:56:37.04 |
-14:57:15.1 |
HIP 98281 |
22.34 |
| 2026-02-17 00:00 |
19:58:01.78 |
-14:57:14.2 |
HIP 98281 |
2.30 |
| 2026-02-17 12:00 |
19:59:26.56 |
-14:57:11.5 |
HIP 98281 |
18.70 |
| 2026-02-18 00:00 |
20:00:51.37 |
-14:57:06.8 |
HIP 98570 |
14.28 |
| 2026-02-18 12:00 |
20:02:16.20 |
-14:57:00.3 |
HIP 98570 |
18.44 |
| 2026-02-19 00:00 |
20:03:41.07 |
-14:56:52.0 |
HIP 98866 |
24.49 |
| 2026-02-19 12:00 |
20:05:05.96 |
-14:56:41.7 |
HIP 99034 |
18.94 |
| 2026-02-20 00:00 |
20:06:30.87 |
-14:56:29.7 |
HIP 99034 |
2.45 |
| 2026-02-20 12:00 |
20:07:55.82 |
-14:56:15.8 |
HIP 99216 |
9.84 |
| 2026-02-21 00:00 |
20:09:20.78 |
-14:56:00.0 |
HIP 99216 |
13.79 |
| 2026-02-21 12:00 |
20:10:45.77 |
-14:55:42.5 |
HIP 99216 |
33.56 |
| 2026-02-22 00:00 |
20:12:10.77 |
-14:55:23.1 |
HIP 99651 |
35.10 |
| 2026-02-22 12:00 |
20:13:35.80 |
-14:55:02.0 |
HIP 99834 |
26.84 |
| 2026-02-23 00:00 |
20:15:00.85 |
-14:54:39.1 |
HIP 99834 |
8.98 |
| 2026-02-23 12:00 |
20:16:25.91 |
-14:54:14.3 |
HIP 99834 |
16.91 |
| 2026-02-24 00:00 |
20:17:51.00 |
-14:53:47.9 |
HIP 99947 |
23.21 |