| Parameter |
Value |
| Designation |
260P/McNaught |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-09-12T14:15:15.050880Z |
| Orbit solution date (soln_date, UTC) |
2026-07-28T14:12:27Z |
| Obs used |
6911 |
| NEO |
- |
| M1 |
12.700 |
| K1 |
13.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-03-29.0000000 |
| e |
0.59479479 |
| q (au) |
1.488496 |
| a (au) |
3.673436 |
| i (deg) |
15.782549 |
| Ω (om, deg) |
351.858406 |
| ω (w, deg) |
15.517670 |
| M (ma, deg) |
129.827068 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.393 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.393 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.998 |
| k |
1.000 |
| 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) |
| 2026-07-29 00:00 |
02:52:22.45 |
+20:42:18.4 |
HIP 13532 |
28.20 |
| 2026-07-29 12:00 |
02:53:49.24 |
+20:55:45.7 |
HIP 13532 |
22.79 |
| 2026-07-30 00:00 |
02:55:16.09 |
+21:09:11.2 |
HIP 13589 |
26.67 |
| 2026-07-30 12:00 |
02:56:43.00 |
+21:22:34.8 |
HIP 13723 |
3.19 |
| 2026-07-31 00:00 |
02:58:09.98 |
+21:35:56.5 |
HIP 13892 |
10.07 |
| 2026-07-31 12:00 |
02:59:37.00 |
+21:49:16.1 |
HIP 13890 |
15.19 |
| 2026-08-01 00:00 |
03:01:04.08 |
+22:02:33.8 |
HIP 14152 |
27.67 |
| 2026-08-01 12:00 |
03:02:31.22 |
+22:15:49.3 |
HIP 14152 |
6.65 |
| 2026-08-02 00:00 |
03:03:58.40 |
+22:29:02.8 |
HIP 14211 |
12.41 |
| 2026-08-02 12:00 |
03:05:25.64 |
+22:42:14.1 |
HIP 14394 |
23.68 |
| 2026-08-03 00:00 |
03:06:52.92 |
+22:55:23.2 |
HIP 14394 |
19.47 |
| 2026-08-03 12:00 |
03:08:20.24 |
+23:08:30.0 |
HIP 14572 |
29.05 |
| 2026-08-04 00:00 |
03:09:47.61 |
+23:21:34.6 |
HIP 14554 |
32.99 |
| 2026-08-04 12:00 |
03:11:15.01 |
+23:34:36.8 |
HIP 14847 |
25.51 |
| 2026-08-05 00:00 |
03:12:42.45 |
+23:47:36.7 |
HIP 14847 |
17.64 |
| 2026-08-05 12:00 |
03:14:09.93 |
+24:00:34.1 |
HIP 15057 |
15.47 |
| 2026-08-06 00:00 |
03:15:37.43 |
+24:13:29.1 |
HIP 15181 |
19.14 |
| 2026-08-06 12:00 |
03:17:04.97 |
+24:26:21.6 |
HIP 15181 |
20.34 |
| 2026-08-07 00:00 |
03:18:32.52 |
+24:39:11.5 |
HIP 15361 |
14.91 |
| 2026-08-07 12:00 |
03:20:00.10 |
+24:51:58.9 |
HIP 15560 |
20.32 |
| 2026-08-08 00:00 |
03:21:27.70 |
+25:04:43.6 |
HIP 15560 |
34.98 |
| 2026-08-08 12:00 |
03:22:55.31 |
+25:17:25.7 |
HIP 15861 |
38.85 |
| 2026-08-09 00:00 |
03:24:22.93 |
+25:30:05.2 |
HIP 15980 |
29.30 |
| 2026-08-09 12:00 |
03:25:50.56 |
+25:42:41.8 |
HIP 15980 |
9.59 |
| 2026-08-10 00:00 |
03:27:18.20 |
+25:55:15.7 |
HIP 15980 |
20.52 |
| 2026-08-10 12:00 |
03:28:45.83 |
+26:07:46.9 |
HIP 16171 |
10.10 |
| 2026-08-11 00:00 |
03:30:13.47 |
+26:20:15.1 |
HIP 16217 |
17.29 |
| 2026-08-11 12:00 |
03:31:41.09 |
+26:32:40.6 |
HIP 16508 |
16.78 |
| 2026-08-12 00:00 |
03:33:08.71 |
+26:45:03.1 |
HIP 16508 |
7.98 |
| 2026-08-12 12:00 |
03:34:36.31 |
+26:57:22.7 |
HIP 16740 |
11.71 |
| 2026-08-13 00:00 |
03:36:03.90 |
+27:09:39.3 |
HIP 16742 |
20.78 |
| 2026-08-13 12:00 |
03:37:31.47 |
+27:21:52.9 |
HIP 16791 |
23.60 |
| 2026-08-14 00:00 |
03:38:59.01 |
+27:34:03.5 |
HIP 17090 |
14.57 |
| 2026-08-14 12:00 |
03:40:26.53 |
+27:46:11.1 |
HIP 17125 |
5.48 |
| 2026-08-15 00:00 |
03:41:54.01 |
+27:58:15.6 |
HIP 17299 |
20.47 |
| 2026-08-15 12:00 |
03:43:21.46 |
+28:10:16.9 |
HIP 17299 |
17.71 |
| 2026-08-16 00:00 |
03:44:48.88 |
+28:22:15.2 |
HIP 17547 |
19.79 |
| 2026-08-16 12:00 |
03:46:16.25 |
+28:34:10.3 |
HIP 17662 |
11.28 |
| 2026-08-17 00:00 |
03:47:43.58 |
+28:46:02.3 |
HIP 17775 |
7.83 |
| 2026-08-17 12:00 |
03:49:10.86 |
+28:57:51.0 |
HIP 17775 |
15.60 |
| 2026-08-18 00:00 |
03:50:38.09 |
+29:09:36.6 |
HIP 17937 |
29.69 |
| 2026-08-18 12:00 |
03:52:05.27 |
+29:21:18.8 |
HIP 18130 |
11.80 |
| 2026-08-19 00:00 |
03:53:32.38 |
+29:32:57.9 |
HIP 18130 |
12.47 |