| 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) |
| 2026-03-26 00:00 |
02:18:23.50 |
+10:01:22.5 |
HIP 10764 |
10.62 |
| 2026-03-26 12:00 |
02:19:27.93 |
+10:07:46.0 |
HIP 10764 |
21.82 |
| 2026-03-27 00:00 |
02:20:32.29 |
+10:14:07.7 |
HIP 10937 |
14.62 |
| 2026-03-27 12:00 |
02:21:36.57 |
+10:20:27.4 |
HIP 10939 |
19.36 |
| 2026-03-28 00:00 |
02:22:40.78 |
+10:26:45.3 |
HIP 11194 |
24.36 |
| 2026-03-28 12:00 |
02:23:44.91 |
+10:33:01.2 |
HIP 11249 |
16.17 |
| 2026-03-29 00:00 |
02:24:48.97 |
+10:39:15.3 |
HIP 11249 |
2.62 |
| 2026-03-29 12:00 |
02:25:52.94 |
+10:45:27.4 |
HIP 11319 |
15.36 |
| 2026-03-30 00:00 |
02:26:56.85 |
+10:51:37.7 |
HIP 11390 |
17.92 |
| 2026-03-30 12:00 |
02:28:00.68 |
+10:57:46.0 |
HIP 11506 |
24.28 |
| 2026-03-31 00:00 |
02:29:04.44 |
+11:03:52.5 |
HIP 11665 |
20.69 |
| 2026-03-31 12:00 |
02:30:08.12 |
+11:09:57.1 |
HIP 11665 |
8.02 |
| 2026-04-01 00:00 |
02:31:11.73 |
+11:15:59.8 |
HIP 11665 |
16.17 |
| 2026-04-01 12:00 |
02:32:15.27 |
+11:22:00.7 |
HIP 11665 |
31.88 |
| 2026-04-02 00:00 |
02:33:18.74 |
+11:27:59.6 |
HIP 11971 |
18.43 |
| 2026-04-02 12:00 |
02:34:22.13 |
+11:33:56.7 |
HIP 11971 |
2.53 |
| 2026-04-03 00:00 |
02:35:25.45 |
+11:39:51.8 |
HIP 11971 |
15.01 |
| 2026-04-03 12:00 |
02:36:28.71 |
+11:45:45.1 |
HIP 12155 |
26.85 |
| 2026-04-04 00:00 |
02:37:31.89 |
+11:51:36.6 |
HIP 12291 |
13.30 |
| 2026-04-04 12:00 |
02:38:35.00 |
+11:57:26.1 |
HIP 12291 |
12.43 |
| 2026-04-05 00:00 |
02:39:38.04 |
+12:03:13.8 |
HIP 12291 |
25.98 |
| 2026-04-05 12:00 |
02:40:41.02 |
+12:08:59.6 |
HIP 12291 |
41.66 |
| 2026-04-06 00:00 |
02:41:43.92 |
+12:14:43.6 |
HIP 12657 |
32.07 |
| 2026-04-06 12:00 |
02:42:46.76 |
+12:20:25.7 |
HIP 12657 |
23.84 |
| 2026-04-07 00:00 |
02:43:49.53 |
+12:26:05.9 |
HIP 12832 |
16.61 |
| 2026-04-07 12:00 |
02:44:52.23 |
+12:31:44.2 |
HIP 12832 |
5.14 |
| 2026-04-08 00:00 |
02:45:54.86 |
+12:37:20.7 |
HIP 12832 |
17.55 |
| 2026-04-08 12:00 |
02:46:57.43 |
+12:42:55.4 |
HIP 12985 |
15.95 |
| 2026-04-09 00:00 |
02:47:59.93 |
+12:48:28.2 |
HIP 12985 |
25.95 |
| 2026-04-09 12:00 |
02:49:02.37 |
+12:53:59.1 |
HIP 13201 |
19.23 |
| 2026-04-10 00:00 |
02:50:04.73 |
+12:59:28.2 |
HIP 13201 |
20.31 |
| 2026-04-10 12:00 |
02:51:07.04 |
+13:04:55.4 |
HIP 13324 |
25.25 |
| 2026-04-11 00:00 |
02:52:09.27 |
+13:10:20.8 |
HIP 13324 |
21.59 |
| 2026-04-11 12:00 |
02:53:11.44 |
+13:15:44.3 |
HIP 13530 |
16.06 |
| 2026-04-12 00:00 |
02:54:13.55 |
+13:21:06.0 |
HIP 13530 |
1.29 |
| 2026-04-12 12:00 |
02:55:15.59 |
+13:26:25.8 |
HIP 13530 |
16.08 |
| 2026-04-13 00:00 |
02:56:17.57 |
+13:31:43.8 |
HIP 13678 |
23.10 |
| 2026-04-13 12:00 |
02:57:19.48 |
+13:37:00.0 |
HIP 13878 |
20.94 |
| 2026-04-14 00:00 |
02:58:21.33 |
+13:42:14.3 |
HIP 13878 |
8.39 |
| 2026-04-14 12:00 |
02:59:23.11 |
+13:47:26.8 |
HIP 13878 |
14.41 |
| 2026-04-15 00:00 |
03:00:24.83 |
+13:52:37.4 |
HIP 13878 |
29.12 |
| 2026-04-15 12:00 |
03:01:26.48 |
+13:57:46.2 |
HIP 14236 |
43.29 |
| 2026-04-16 00:00 |
03:02:28.07 |
+14:02:53.2 |
HIP 14236 |
29.89 |