| Parameter |
Value |
| Designation |
260P/McNaught |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-09-13T11:28:52.973760Z |
| Orbit solution date (soln_date, UTC) |
2026-09-21T07:12:14Z |
| Obs used |
7386 |
| NEO |
- |
| M1 |
12.800 |
| K1 |
12.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2016-02-08.0000000 |
| e |
0.59701636 |
| q (au) |
1.477756 |
| a (au) |
3.667037 |
| i (deg) |
15.805844 |
| Ω (om, deg) |
351.866496 |
| ω (w, deg) |
15.380561 |
| M (ma, deg) |
174.395392 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.387 + 5.922\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.387 |
| n |
5.922 |
| gf |
0.800 |
| gb |
-0.613 |
| k |
1.000 |
| δ90 |
9.998 |
| 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) |
| 2026-09-20 00:00 |
05:20:37.62 |
+40:01:41.4 |
HIP 24884 |
15.65 |
| 2026-09-20 12:00 |
05:21:49.36 |
+40:09:47.1 |
HIP 25198 |
18.86 |
| 2026-09-21 00:00 |
05:23:00.66 |
+40:17:50.0 |
HIP 25198 |
10.08 |
| 2026-09-21 12:00 |
05:24:11.49 |
+40:25:50.3 |
HIP 25198 |
18.58 |
| 2026-09-22 00:00 |
05:25:21.86 |
+40:33:47.8 |
HIP 25198 |
32.78 |
| 2026-09-22 12:00 |
05:26:31.75 |
+40:41:42.7 |
HIP 25585 |
26.40 |
| 2026-09-23 00:00 |
05:27:41.16 |
+40:49:34.9 |
HIP 25585 |
27.92 |
| 2026-09-23 12:00 |
05:28:50.09 |
+40:57:24.5 |
HIP 25773 |
25.03 |
| 2026-09-24 00:00 |
05:29:58.51 |
+41:05:11.6 |
HIP 25773 |
12.07 |
| 2026-09-24 12:00 |
05:31:06.44 |
+41:12:56.1 |
HIP 25773 |
10.80 |
| 2026-09-25 00:00 |
05:32:13.86 |
+41:20:38.1 |
HIP 25816 |
17.48 |
| 2026-09-25 12:00 |
05:33:20.76 |
+41:28:17.7 |
HIP 26128 |
23.41 |
| 2026-09-26 00:00 |
05:34:27.14 |
+41:35:54.8 |
HIP 26244 |
11.67 |
| 2026-09-26 12:00 |
05:35:32.98 |
+41:43:29.5 |
HIP 26244 |
11.19 |
| 2026-09-27 00:00 |
05:36:38.28 |
+41:51:01.8 |
HIP 26392 |
5.55 |
| 2026-09-27 12:00 |
05:37:43.04 |
+41:58:31.7 |
HIP 26392 |
11.07 |
| 2026-09-28 00:00 |
05:38:47.24 |
+42:05:59.4 |
HIP 26546 |
15.64 |
| 2026-09-28 12:00 |
05:39:50.88 |
+42:13:24.8 |
HIP 26546 |
26.20 |
| 2026-09-29 00:00 |
05:40:53.94 |
+42:20:47.9 |
HIP 26613 |
25.79 |
| 2026-09-29 12:00 |
05:41:56.43 |
+42:28:08.7 |
HIP 26979 |
19.15 |
| 2026-09-30 00:00 |
05:42:58.32 |
+42:35:27.4 |
HIP 26979 |
16.79 |
| 2026-09-30 12:00 |
05:43:59.62 |
+42:42:44.0 |
HIP 27178 |
19.94 |
| 2026-10-01 00:00 |
05:45:00.31 |
+42:49:58.4 |
HIP 27178 |
6.87 |
| 2026-10-01 12:00 |
05:46:00.39 |
+42:57:10.7 |
HIP 27178 |
6.93 |
| 2026-10-02 00:00 |
05:46:59.84 |
+43:04:21.0 |
HIP 27178 |
19.75 |
| 2026-10-02 12:00 |
05:47:58.66 |
+43:11:29.2 |
HIP 27313 |
19.46 |
| 2026-10-03 00:00 |
05:48:56.84 |
+43:18:35.4 |
HIP 27313 |
21.91 |
| 2026-10-03 12:00 |
05:49:54.37 |
+43:25:39.6 |
HIP 27608 |
18.17 |
| 2026-10-04 00:00 |
05:50:51.24 |
+43:32:41.9 |
HIP 27608 |
8.74 |
| 2026-10-04 12:00 |
05:51:47.44 |
+43:39:42.2 |
HIP 27608 |
11.45 |
| 2026-10-05 00:00 |
05:52:42.97 |
+43:46:40.6 |
HIP 27608 |
21.99 |
| 2026-10-05 12:00 |
05:53:37.80 |
+43:53:37.2 |
HIP 27848 |
22.82 |
| 2026-10-06 00:00 |
05:54:31.95 |
+44:00:31.9 |
HIP 27848 |
19.30 |
| 2026-10-06 12:00 |
05:55:25.39 |
+44:07:24.8 |
HIP 27848 |
22.42 |
| 2026-10-07 00:00 |
05:56:18.11 |
+44:14:15.8 |
HIP 27848 |
30.03 |
| 2026-10-07 12:00 |
05:57:10.12 |
+44:21:05.1 |
HIP 28438 |
36.65 |
| 2026-10-08 00:00 |
05:58:01.39 |
+44:27:52.6 |
HIP 28438 |
25.68 |
| 2026-10-08 12:00 |
05:58:51.93 |
+44:34:38.4 |
HIP 28438 |
15.52 |
| 2026-10-09 00:00 |
05:59:41.72 |
+44:41:22.4 |
HIP 28438 |
8.83 |
| 2026-10-09 12:00 |
06:00:30.75 |
+44:48:04.7 |
HIP 28438 |
12.73 |
| 2026-10-10 00:00 |
06:01:19.02 |
+44:54:45.3 |
HIP 28527 |
14.88 |
| 2026-10-10 12:00 |
06:02:06.52 |
+45:01:24.2 |
HIP 28527 |
11.93 |
| 2026-10-11 00:00 |
06:02:53.25 |
+45:08:01.4 |
HIP 28527 |
16.95 |