| Parameter |
Value |
| Designation |
P/2008 Y3 (McNaught) |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2009-01-11T23:10:23.174400Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:26Z |
| Obs used |
164 |
| NEO |
- |
| M1 |
4.500 |
| K1 |
16.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2009-02-17.0000000 |
| e |
0.44766720 |
| q (au) |
4.434244 |
| a (au) |
8.028211 |
| i (deg) |
38.813188 |
| Ω (om, deg) |
262.934144 |
| ω (w, deg) |
238.279400 |
| M (ma, deg) |
1.561327 |
Magnitude
Scatter + Global Linear
$$
M_a = (4.713 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
4.713 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
23:54:49.16 |
+44:05:01.1 |
HIP 117834 |
30.09 |
| 2026-09-20 12:00 |
23:54:36.34 |
+44:04:19.8 |
HIP 117834 |
30.06 |
| 2026-09-21 00:00 |
23:54:23.51 |
+44:03:37.1 |
HIP 117834 |
30.24 |
| 2026-09-21 12:00 |
23:54:10.67 |
+44:02:53.0 |
HIP 117834 |
30.64 |
| 2026-09-22 00:00 |
23:53:57.83 |
+44:02:07.5 |
HIP 117834 |
31.24 |
| 2026-09-22 12:00 |
23:53:44.99 |
+44:01:20.5 |
HIP 117834 |
32.03 |
| 2026-09-23 00:00 |
23:53:32.14 |
+44:00:32.1 |
HIP 117834 |
33.01 |
| 2026-09-23 12:00 |
23:53:19.29 |
+43:59:42.4 |
HIP 117695 |
31.79 |
| 2026-09-24 00:00 |
23:53:06.45 |
+43:58:51.2 |
HIP 117695 |
30.14 |
| 2026-09-24 12:00 |
23:52:53.61 |
+43:57:58.6 |
HIP 117695 |
28.59 |
| 2026-09-25 00:00 |
23:52:40.77 |
+43:57:04.6 |
HIP 117695 |
27.15 |
| 2026-09-25 12:00 |
23:52:27.94 |
+43:56:09.2 |
HIP 117695 |
25.85 |
| 2026-09-26 00:00 |
23:52:15.12 |
+43:55:12.4 |
HIP 117695 |
24.71 |
| 2026-09-26 12:00 |
23:52:02.31 |
+43:54:14.3 |
HIP 117695 |
23.76 |
| 2026-09-27 00:00 |
23:51:49.52 |
+43:53:14.8 |
HIP 117695 |
23.01 |
| 2026-09-27 12:00 |
23:51:36.73 |
+43:52:13.9 |
HIP 117695 |
22.51 |
| 2026-09-28 00:00 |
23:51:23.96 |
+43:51:11.6 |
HIP 117620 |
21.34 |
| 2026-09-28 12:00 |
23:51:11.21 |
+43:50:08.0 |
HIP 117620 |
20.28 |
| 2026-09-29 00:00 |
23:50:58.48 |
+43:49:03.0 |
HIP 117620 |
19.47 |
| 2026-09-29 12:00 |
23:50:45.77 |
+43:47:56.6 |
HIP 117620 |
18.95 |
| 2026-09-30 00:00 |
23:50:33.09 |
+43:46:49.0 |
HIP 117620 |
18.74 |
| 2026-09-30 12:00 |
23:50:20.42 |
+43:45:39.9 |
HIP 117620 |
18.86 |
| 2026-10-01 00:00 |
23:50:07.79 |
+43:44:29.6 |
HIP 117620 |
19.30 |
| 2026-10-01 12:00 |
23:49:55.18 |
+43:43:17.9 |
HIP 117565 |
19.26 |
| 2026-10-02 00:00 |
23:49:42.60 |
+43:42:04.8 |
HIP 117565 |
19.05 |
| 2026-10-02 12:00 |
23:49:30.05 |
+43:40:50.5 |
HIP 117565 |
19.17 |
| 2026-10-03 00:00 |
23:49:17.54 |
+43:39:34.8 |
HIP 117565 |
19.62 |
| 2026-10-03 12:00 |
23:49:05.06 |
+43:38:17.9 |
HIP 117565 |
20.36 |
| 2026-10-04 00:00 |
23:48:52.62 |
+43:36:59.6 |
HIP 117309 |
18.47 |
| 2026-10-04 12:00 |
23:48:40.22 |
+43:35:40.1 |
HIP 117309 |
16.05 |
| 2026-10-05 00:00 |
23:48:27.86 |
+43:34:19.3 |
HIP 117309 |
13.71 |
| 2026-10-05 12:00 |
23:48:15.54 |
+43:32:57.1 |
HIP 117309 |
11.48 |
| 2026-10-06 00:00 |
23:48:03.26 |
+43:31:33.8 |
HIP 117309 |
9.48 |
| 2026-10-06 12:00 |
23:47:51.03 |
+43:30:09.2 |
HIP 117309 |
7.86 |
| 2026-10-07 00:00 |
23:47:38.85 |
+43:28:43.3 |
HIP 117309 |
6.91 |
| 2026-10-07 12:00 |
23:47:26.72 |
+43:27:16.2 |
HIP 117309 |
6.92 |
| 2026-10-08 00:00 |
23:47:14.64 |
+43:25:47.8 |
HIP 117309 |
7.89 |
| 2026-10-08 12:00 |
23:47:02.61 |
+43:24:18.2 |
HIP 117309 |
9.53 |
| 2026-10-09 00:00 |
23:46:50.64 |
+43:22:47.5 |
HIP 117309 |
11.57 |
| 2026-10-09 12:00 |
23:46:38.73 |
+43:21:15.5 |
HIP 117309 |
13.83 |
| 2026-10-10 00:00 |
23:46:26.88 |
+43:19:42.3 |
HIP 117309 |
16.22 |
| 2026-10-10 12:00 |
23:46:15.08 |
+43:18:08.0 |
HIP 117309 |
18.69 |
| 2026-10-11 00:00 |
23:46:03.35 |
+43:16:32.5 |
HIP 117230 |
19.98 |