508P/McNaught
| Parameter |
Value |
| Designation |
508P/McNaught |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-01-15T03:13:20.297280Z |
| Orbit solution date (soln_date, UTC) |
2025-09-16T17:21:53Z |
| Obs used |
115 |
| NEO |
- |
| M1 |
14.400 |
| K1 |
23.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-12-17.0000000 |
| e |
0.57045556 |
| q (au) |
1.533483 |
| a (au) |
3.570023 |
| i (deg) |
31.765073 |
| Ω (om, deg) |
268.821639 |
| ω (w, deg) |
339.031332 |
| M (ma, deg) |
195.746050 |
Magnitude
Scatter + Global Linear
$$
M_a = (19.357 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
19.357 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
21:38:38.23 |
+09:13:00.7 |
HIP 106981 |
20.73 |
| 2026-02-03 12:00 |
21:39:31.51 |
+09:18:46.0 |
HIP 106981 |
10.73 |
| 2026-02-04 00:00 |
21:40:24.71 |
+09:24:31.7 |
HIP 106981 |
14.58 |
| 2026-02-04 12:00 |
21:41:17.82 |
+09:30:17.9 |
HIP 107031 |
19.36 |
| 2026-02-05 00:00 |
21:42:10.86 |
+09:36:04.6 |
HIP 107031 |
25.92 |
| 2026-02-05 12:00 |
21:43:03.82 |
+09:41:51.6 |
HIP 107315 |
19.70 |
| 2026-02-06 00:00 |
21:43:56.71 |
+09:47:39.2 |
HIP 107315 |
6.01 |
| 2026-02-06 12:00 |
21:44:49.51 |
+09:53:27.1 |
HIP 107315 |
9.50 |
| 2026-02-07 00:00 |
21:45:42.24 |
+09:59:15.5 |
HIP 107315 |
23.43 |
| 2026-02-07 12:00 |
21:46:34.88 |
+10:05:04.3 |
HIP 107591 |
19.91 |
| 2026-02-08 00:00 |
21:47:27.45 |
+10:10:53.6 |
HIP 107591 |
9.02 |
| 2026-02-08 12:00 |
21:48:19.94 |
+10:16:43.3 |
HIP 107591 |
12.95 |
| 2026-02-09 00:00 |
21:49:12.36 |
+10:22:33.4 |
HIP 107591 |
25.58 |
| 2026-02-09 12:00 |
21:50:04.69 |
+10:28:23.9 |
HIP 107858 |
16.67 |
| 2026-02-10 00:00 |
21:50:56.95 |
+10:34:14.8 |
HIP 107858 |
12.44 |
| 2026-02-10 12:00 |
21:51:49.13 |
+10:40:06.2 |
HIP 107858 |
20.73 |
| 2026-02-11 00:00 |
21:52:41.23 |
+10:45:57.9 |
HIP 107919 |
22.96 |
| 2026-02-11 12:00 |
21:53:33.25 |
+10:51:50.1 |
HIP 107919 |
28.38 |
| 2026-02-12 00:00 |
21:54:25.20 |
+10:57:42.6 |
HIP 108228 |
16.97 |
| 2026-02-12 12:00 |
21:55:17.07 |
+11:03:35.6 |
HIP 108228 |
11.33 |
| 2026-02-13 00:00 |
21:56:08.86 |
+11:09:28.9 |
HIP 108228 |
19.02 |
| 2026-02-13 12:00 |
21:57:00.57 |
+11:15:22.6 |
HIP 108367 |
12.99 |
| 2026-02-14 00:00 |
21:57:52.20 |
+11:21:16.7 |
HIP 108367 |
11.65 |
| 2026-02-14 12:00 |
21:58:43.75 |
+11:27:11.2 |
HIP 108367 |
22.17 |
| 2026-02-15 00:00 |
21:59:35.23 |
+11:33:06.1 |
HIP 108367 |
35.14 |
| 2026-02-15 12:00 |
22:00:26.62 |
+11:39:01.3 |
HIP 108806 |
34.70 |
| 2026-02-16 00:00 |
22:01:17.94 |
+11:44:56.9 |
HIP 108806 |
28.84 |
| 2026-02-16 12:00 |
22:02:09.18 |
+11:50:52.8 |
HIP 108822 |
18.96 |
| 2026-02-17 00:00 |
22:03:00.34 |
+11:56:49.1 |
HIP 108822 |
11.21 |
| 2026-02-17 12:00 |
22:03:51.42 |
+12:02:45.7 |
HIP 108822 |
16.58 |
| 2026-02-18 00:00 |
22:04:42.42 |
+12:08:42.7 |
HIP 109067 |
19.91 |
| 2026-02-18 12:00 |
22:05:33.34 |
+12:14:40.0 |
HIP 109067 |
8.19 |
| 2026-02-19 00:00 |
22:06:24.18 |
+12:20:37.7 |
HIP 109147 |
6.53 |
| 2026-02-19 12:00 |
22:07:14.94 |
+12:26:35.7 |
HIP 109147 |
10.02 |
| 2026-02-20 00:00 |
22:08:05.62 |
+12:32:34.0 |
HIP 109147 |
23.14 |
| 2026-02-20 12:00 |
22:08:56.23 |
+12:38:32.6 |
HIP 109251 |
29.28 |
| 2026-02-21 00:00 |
22:09:46.75 |
+12:44:31.5 |
HIP 109516 |
28.44 |
| 2026-02-21 12:00 |
22:10:37.19 |
+12:50:30.7 |
HIP 109516 |
27.72 |
| 2026-02-22 00:00 |
22:11:27.55 |
+12:56:30.2 |
HIP 109716 |
31.58 |
| 2026-02-22 12:00 |
22:12:17.82 |
+13:02:30.0 |
HIP 109716 |
25.28 |
| 2026-02-23 00:00 |
22:13:08.02 |
+13:08:30.1 |
HIP 109716 |
25.56 |
| 2026-02-23 12:00 |
22:13:58.14 |
+13:14:30.4 |
HIP 109716 |
32.24 |
| 2026-02-24 00:00 |
22:14:48.17 |
+13:20:31.0 |
HIP 109938 |
32.64 |