| Parameter |
Value |
| Designation |
260P/McNaught |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-09-12T12:20:24.253440Z |
| Orbit solution date (soln_date, UTC) |
2026-05-08T13:42:15Z |
| Obs used |
6737 |
| NEO |
- |
| M1 |
12.700 |
| K1 |
13.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-11-12.0000000 |
| e |
0.59434161 |
| q (au) |
1.490998 |
| a (au) |
3.675502 |
| i (deg) |
15.771072 |
| Ω (om, deg) |
351.861753 |
| ω (w, deg) |
15.567885 |
| M (ma, deg) |
110.566394 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.521 + 5.334\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.521 |
| n |
5.334 |
| gf |
1.000 |
| gb |
-0.692 |
| k |
0.957 |
| 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) |
| 2026-05-12 00:00 |
23:22:19.30 |
-12:59:49.8 |
HIP 115308 |
18.87 |
| 2026-05-12 12:00 |
23:23:35.46 |
-12:49:23.3 |
HIP 115629 |
32.27 |
| 2026-05-13 00:00 |
23:24:51.65 |
-12:38:54.0 |
HIP 115629 |
11.11 |
| 2026-05-13 12:00 |
23:26:07.87 |
-12:28:22.1 |
HIP 115629 |
10.81 |
| 2026-05-14 00:00 |
23:27:24.12 |
-12:17:47.3 |
HIP 115844 |
11.69 |
| 2026-05-14 12:00 |
23:28:40.41 |
-12:07:09.9 |
HIP 115844 |
9.83 |
| 2026-05-15 00:00 |
23:29:56.73 |
-11:56:29.7 |
HIP 116078 |
24.87 |
| 2026-05-15 12:00 |
23:31:13.09 |
-11:45:46.8 |
HIP 116128 |
14.47 |
| 2026-05-16 00:00 |
23:32:29.47 |
-11:35:01.1 |
HIP 116163 |
4.74 |
| 2026-05-16 12:00 |
23:33:45.90 |
-11:24:12.8 |
HIP 116398 |
23.55 |
| 2026-05-17 00:00 |
23:35:02.35 |
-11:13:21.8 |
HIP 116398 |
21.43 |
| 2026-05-17 12:00 |
23:36:18.84 |
-11:02:28.0 |
HIP 116469 |
21.85 |
| 2026-05-18 00:00 |
23:37:35.36 |
-10:51:31.6 |
HIP 116469 |
26.15 |
| 2026-05-18 12:00 |
23:38:51.92 |
-10:40:32.5 |
HIP 116811 |
35.93 |
| 2026-05-19 00:00 |
23:40:08.52 |
-10:29:30.7 |
HIP 116811 |
16.62 |
| 2026-05-19 12:00 |
23:41:25.15 |
-10:18:26.2 |
HIP 116811 |
14.64 |
| 2026-05-20 00:00 |
23:42:41.82 |
-10:07:19.1 |
HIP 117044 |
30.07 |
| 2026-05-20 12:00 |
23:43:58.52 |
-09:56:09.2 |
HIP 117044 |
16.63 |
| 2026-05-21 00:00 |
23:45:15.26 |
-09:44:56.8 |
HIP 117044 |
24.75 |
| 2026-05-21 12:00 |
23:46:32.05 |
-09:33:41.6 |
HIP 117318 |
18.90 |
| 2026-05-22 00:00 |
23:47:48.87 |
-09:22:23.9 |
HIP 117318 |
27.11 |
| 2026-05-22 12:00 |
23:49:05.73 |
-09:11:03.4 |
HIP 117533 |
27.61 |
| 2026-05-23 00:00 |
23:50:22.63 |
-08:59:40.4 |
HIP 117533 |
34.08 |
| 2026-05-23 12:00 |
23:51:39.58 |
-08:48:14.7 |
HIP 117743 |
17.02 |
| 2026-05-24 00:00 |
23:52:56.57 |
-08:36:46.4 |
HIP 117743 |
17.17 |
| 2026-05-24 12:00 |
23:54:13.60 |
-08:25:15.4 |
HIP 117924 |
13.26 |
| 2026-05-25 00:00 |
23:55:30.67 |
-08:13:41.8 |
HIP 117924 |
14.07 |
| 2026-05-25 12:00 |
23:56:47.80 |
-08:02:05.7 |
HIP 117924 |
34.89 |
| 2026-05-26 00:00 |
23:58:04.97 |
-07:50:26.9 |
HIP 118294 |
22.40 |
| 2026-05-26 12:00 |
23:59:22.18 |
-07:38:45.5 |
HIP 118294 |
10.38 |
| 2026-05-27 00:00 |
00:00:39.44 |
-07:27:01.6 |
HIP 118294 |
26.85 |
| 2026-05-27 12:00 |
00:01:56.76 |
-07:15:15.1 |
HIP 245 |
37.50 |
| 2026-05-28 00:00 |
00:03:14.12 |
-07:03:26.0 |
HIP 356 |
19.66 |
| 2026-05-28 12:00 |
00:04:31.53 |
-06:51:34.4 |
HIP 356 |
6.36 |
| 2026-05-29 00:00 |
00:05:49.00 |
-06:39:40.2 |
HIP 356 |
26.76 |
| 2026-05-29 12:00 |
00:07:06.51 |
-06:27:43.5 |
HIP 552 |
13.15 |
| 2026-05-30 00:00 |
00:08:24.08 |
-06:15:44.2 |
HIP 552 |
24.55 |
| 2026-05-30 12:00 |
00:09:41.71 |
-06:03:42.5 |
HIP 849 |
10.83 |
| 2026-05-31 00:00 |
00:10:59.38 |
-05:51:38.3 |
HIP 897 |
4.77 |
| 2026-05-31 12:00 |
00:12:17.12 |
-05:39:31.5 |
HIP 897 |
19.57 |
| 2026-06-01 00:00 |
00:13:34.91 |
-05:27:22.4 |
HIP 1062 |
14.04 |
| 2026-06-01 12:00 |
00:14:52.75 |
-05:15:10.7 |
HIP 1062 |
25.05 |
| 2026-06-02 00:00 |
00:16:10.66 |
-05:02:56.6 |
HIP 1324 |
8.08 |