| Parameter |
Value |
| Designation |
508P/McNaught |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2012-01-15T03:13:20.297280Z |
| Orbit solution date (soln_date, UTC) |
2026-03-12T02:49:59Z |
| Obs used |
115 |
| NEO |
- |
| M1 |
14.400 |
| K1 |
23.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2005-05-03T17:19:54.624000Z |
| Discovery magnitude (MPC) |
17.60 T |
| Discovery observatory (MPC) |
E12 · Siding Spring Survey |
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) |
| 2026-07-29 00:00 |
01:03:41.69 |
+42:47:52.5 |
HIP 4883 |
10.61 |
| 2026-07-29 12:00 |
01:03:44.05 |
+42:52:02.6 |
HIP 4883 |
11.25 |
| 2026-07-30 00:00 |
01:03:46.08 |
+42:56:11.1 |
HIP 4883 |
13.19 |
| 2026-07-30 12:00 |
01:03:47.77 |
+43:00:18.1 |
HIP 4883 |
15.94 |
| 2026-07-31 00:00 |
01:03:49.12 |
+43:04:23.4 |
HIP 5078 |
17.82 |
| 2026-07-31 12:00 |
01:03:50.13 |
+43:08:27.2 |
HIP 4913 |
14.81 |
| 2026-08-01 00:00 |
01:03:50.81 |
+43:12:29.3 |
HIP 4913 |
11.90 |
| 2026-08-01 12:00 |
01:03:51.14 |
+43:16:29.7 |
HIP 4913 |
9.78 |
| 2026-08-02 00:00 |
01:03:51.13 |
+43:20:28.5 |
HIP 4913 |
8.98 |
| 2026-08-02 12:00 |
01:03:50.78 |
+43:24:25.6 |
HIP 4913 |
9.79 |
| 2026-08-03 00:00 |
01:03:50.08 |
+43:28:20.9 |
HIP 4913 |
11.87 |
| 2026-08-03 12:00 |
01:03:49.03 |
+43:32:14.5 |
HIP 4913 |
14.66 |
| 2026-08-04 00:00 |
01:03:47.64 |
+43:36:06.3 |
HIP 4913 |
17.81 |
| 2026-08-04 12:00 |
01:03:45.90 |
+43:39:56.3 |
HIP 4913 |
21.15 |
| 2026-08-05 00:00 |
01:03:43.81 |
+43:43:44.5 |
HIP 4970 |
20.25 |
| 2026-08-05 12:00 |
01:03:41.37 |
+43:47:30.8 |
HIP 4970 |
16.47 |
| 2026-08-06 00:00 |
01:03:38.57 |
+43:51:15.3 |
HIP 4970 |
12.74 |
| 2026-08-06 12:00 |
01:03:35.42 |
+43:54:57.8 |
HIP 4970 |
9.08 |
| 2026-08-07 00:00 |
01:03:31.92 |
+43:58:38.4 |
HIP 4970 |
5.61 |
| 2026-08-07 12:00 |
01:03:28.06 |
+44:02:17.1 |
HIP 4970 |
2.93 |
| 2026-08-08 00:00 |
01:03:23.85 |
+44:05:53.7 |
HIP 4970 |
3.68 |
| 2026-08-08 12:00 |
01:03:19.27 |
+44:09:28.4 |
HIP 4970 |
6.77 |
| 2026-08-09 00:00 |
01:03:14.34 |
+44:13:01.0 |
HIP 4970 |
10.25 |
| 2026-08-09 12:00 |
01:03:09.05 |
+44:16:31.5 |
HIP 4970 |
13.81 |
| 2026-08-10 00:00 |
01:03:03.41 |
+44:20:00.0 |
HIP 4970 |
17.40 |
| 2026-08-10 12:00 |
01:02:57.40 |
+44:23:26.3 |
HIP 5032 |
16.92 |
| 2026-08-11 00:00 |
01:02:51.03 |
+44:26:50.4 |
HIP 5032 |
17.24 |
| 2026-08-11 12:00 |
01:02:44.30 |
+44:30:12.4 |
HIP 5032 |
18.33 |
| 2026-08-12 00:00 |
01:02:37.21 |
+44:33:32.1 |
HIP 5032 |
20.06 |
| 2026-08-12 12:00 |
01:02:29.77 |
+44:36:49.6 |
HIP 5032 |
22.27 |
| 2026-08-13 00:00 |
01:02:21.96 |
+44:40:04.8 |
HIP 4675 |
24.75 |
| 2026-08-13 12:00 |
01:02:13.79 |
+44:43:17.7 |
HIP 4675 |
23.14 |
| 2026-08-14 00:00 |
01:02:05.25 |
+44:46:28.3 |
HIP 4675 |
21.92 |
| 2026-08-14 12:00 |
01:01:56.36 |
+44:49:36.5 |
HIP 4675 |
21.15 |
| 2026-08-15 00:00 |
01:01:47.11 |
+44:52:42.3 |
HIP 4675 |
20.87 |
| 2026-08-15 12:00 |
01:01:37.51 |
+44:55:45.6 |
HIP 4675 |
21.11 |
| 2026-08-16 00:00 |
01:01:27.54 |
+44:58:46.6 |
HIP 4675 |
21.84 |
| 2026-08-16 12:00 |
01:01:17.21 |
+45:01:45.0 |
HIP 4675 |
23.01 |
| 2026-08-17 00:00 |
01:01:06.53 |
+45:04:41.0 |
HIP 4771 |
22.55 |
| 2026-08-17 12:00 |
01:00:55.50 |
+45:07:34.4 |
HIP 4771 |
19.98 |
| 2026-08-18 00:00 |
01:00:44.10 |
+45:10:25.3 |
HIP 4771 |
17.79 |
| 2026-08-18 12:00 |
01:00:32.36 |
+45:13:13.5 |
HIP 4639 |
15.12 |
| 2026-08-19 00:00 |
01:00:20.26 |
+45:15:59.2 |
HIP 4639 |
11.64 |