| 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 |
0.999 |
| gb |
-1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
23:33:43.29 |
+34:43:20.5 |
HIP 116181 |
21.21 |
| 2026-03-26 12:00 |
23:33:59.78 |
+34:44:48.8 |
HIP 116181 |
23.06 |
| 2026-03-27 00:00 |
23:34:16.25 |
+34:46:17.8 |
HIP 116348 |
25.21 |
| 2026-03-27 12:00 |
23:34:32.71 |
+34:47:47.4 |
HIP 116348 |
26.43 |
| 2026-03-28 00:00 |
23:34:49.15 |
+34:49:17.6 |
HIP 116474 |
23.21 |
| 2026-03-28 12:00 |
23:35:05.58 |
+34:50:48.6 |
HIP 116474 |
19.92 |
| 2026-03-29 00:00 |
23:35:21.99 |
+34:52:20.1 |
HIP 116474 |
16.79 |
| 2026-03-29 12:00 |
23:35:38.39 |
+34:53:52.3 |
HIP 116474 |
13.93 |
| 2026-03-30 00:00 |
23:35:54.77 |
+34:55:25.1 |
HIP 116474 |
11.54 |
| 2026-03-30 12:00 |
23:36:11.13 |
+34:56:58.6 |
HIP 116474 |
9.96 |
| 2026-03-31 00:00 |
23:36:27.47 |
+34:58:32.6 |
HIP 116474 |
9.62 |
| 2026-03-31 12:00 |
23:36:43.79 |
+35:00:07.3 |
HIP 116474 |
10.62 |
| 2026-04-01 00:00 |
23:37:00.10 |
+35:01:42.7 |
HIP 116474 |
12.66 |
| 2026-04-01 12:00 |
23:37:16.39 |
+35:03:18.6 |
HIP 116474 |
15.32 |
| 2026-04-02 00:00 |
23:37:32.65 |
+35:04:55.1 |
HIP 116667 |
12.92 |
| 2026-04-02 12:00 |
23:37:48.90 |
+35:06:32.3 |
HIP 116667 |
10.31 |
| 2026-04-03 00:00 |
23:38:05.12 |
+35:08:10.0 |
HIP 116667 |
8.56 |
| 2026-04-03 12:00 |
23:38:21.33 |
+35:09:48.4 |
HIP 116667 |
8.24 |
| 2026-04-04 00:00 |
23:38:37.51 |
+35:11:27.3 |
HIP 116667 |
9.48 |
| 2026-04-04 12:00 |
23:38:53.67 |
+35:13:06.8 |
HIP 116667 |
11.81 |
| 2026-04-05 00:00 |
23:39:09.80 |
+35:14:47.0 |
HIP 116667 |
14.72 |
| 2026-04-05 12:00 |
23:39:25.91 |
+35:16:27.7 |
HIP 116667 |
17.92 |
| 2026-04-06 00:00 |
23:39:42.00 |
+35:18:09.0 |
HIP 116671 |
18.96 |
| 2026-04-06 12:00 |
23:39:58.07 |
+35:19:50.8 |
HIP 116671 |
20.24 |
| 2026-04-07 00:00 |
23:40:14.10 |
+35:21:33.3 |
HIP 116671 |
22.05 |
| 2026-04-07 12:00 |
23:40:30.12 |
+35:23:16.3 |
HIP 116671 |
24.28 |
| 2026-04-08 00:00 |
23:40:46.10 |
+35:24:59.8 |
HIP 116671 |
26.83 |
| 2026-04-08 12:00 |
23:41:02.06 |
+35:26:44.0 |
HIP 116671 |
29.60 |
| 2026-04-09 00:00 |
23:41:17.99 |
+35:28:28.7 |
HIP 116842 |
30.04 |
| 2026-04-09 12:00 |
23:41:33.90 |
+35:30:13.9 |
HIP 116842 |
28.88 |
| 2026-04-10 00:00 |
23:41:49.77 |
+35:31:59.7 |
HIP 116842 |
28.15 |
| 2026-04-10 12:00 |
23:42:05.62 |
+35:33:46.1 |
HIP 116842 |
27.87 |
| 2026-04-11 00:00 |
23:42:21.44 |
+35:35:33.0 |
HIP 116842 |
28.06 |
| 2026-04-11 12:00 |
23:42:37.22 |
+35:37:20.4 |
HIP 116842 |
28.71 |
| 2026-04-12 00:00 |
23:42:52.98 |
+35:39:08.3 |
HIP 116842 |
29.79 |
| 2026-04-12 12:00 |
23:43:08.70 |
+35:40:56.8 |
HIP 116842 |
31.25 |
| 2026-04-13 00:00 |
23:43:24.39 |
+35:42:45.9 |
HIP 116842 |
33.05 |
| 2026-04-13 12:00 |
23:43:40.05 |
+35:44:35.4 |
HIP 116842 |
35.12 |
| 2026-04-14 00:00 |
23:43:55.68 |
+35:46:25.5 |
HIP 117094 |
34.17 |
| 2026-04-14 12:00 |
23:44:11.27 |
+35:48:16.0 |
HIP 117094 |
32.08 |
| 2026-04-15 00:00 |
23:44:26.83 |
+35:50:07.1 |
HIP 117132 |
29.93 |
| 2026-04-15 12:00 |
23:44:42.35 |
+35:51:58.7 |
HIP 117197 |
26.95 |
| 2026-04-16 00:00 |
23:44:57.83 |
+35:53:50.8 |
HIP 117197 |
23.83 |