| Parameter |
Value |
| Designation |
C/2007 Y2 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-04-08T09:35:06.708480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:15Z |
| Obs used |
81 |
| NEO |
- |
| M1 |
9.200 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-03-10.0000000 |
| e |
0.99652600 |
| q (au) |
4.208958 |
| a (au) |
1211.561103 |
| i (deg) |
98.503197 |
| Ω (om, deg) |
303.462012 |
| ω (w, deg) |
257.686731 |
| M (ma, deg) |
359.999313 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.768 + 3.627\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.768 |
| n |
3.627 |
| gf |
0.997 |
| gb |
-1.000 |
| k |
0.998 |
| 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) |
| 2026-06-01 00:00 |
19:32:54.34 |
+16:31:52.3 |
HIP 96078 |
12.51 |
| 2026-06-01 12:00 |
19:32:51.60 |
+16:32:12.3 |
HIP 96078 |
11.98 |
| 2026-06-02 00:00 |
19:32:48.85 |
+16:32:32.1 |
HIP 96078 |
11.47 |
| 2026-06-02 12:00 |
19:32:46.07 |
+16:32:51.7 |
HIP 96078 |
10.98 |
| 2026-06-03 00:00 |
19:32:43.27 |
+16:33:11.0 |
HIP 96078 |
10.51 |
| 2026-06-03 12:00 |
19:32:40.45 |
+16:33:30.1 |
HIP 96078 |
10.07 |
| 2026-06-04 00:00 |
19:32:37.62 |
+16:33:49.0 |
HIP 96078 |
9.65 |
| 2026-06-04 12:00 |
19:32:34.76 |
+16:34:07.6 |
HIP 96078 |
9.28 |
| 2026-06-05 00:00 |
19:32:31.89 |
+16:34:26.0 |
HIP 96078 |
8.95 |
| 2026-06-05 12:00 |
19:32:29.00 |
+16:34:44.1 |
HIP 96078 |
8.66 |
| 2026-06-06 00:00 |
19:32:26.09 |
+16:35:02.0 |
HIP 96078 |
8.43 |
| 2026-06-06 12:00 |
19:32:23.16 |
+16:35:19.7 |
HIP 96078 |
8.25 |
| 2026-06-07 00:00 |
19:32:20.21 |
+16:35:37.1 |
HIP 96078 |
8.13 |
| 2026-06-07 12:00 |
19:32:17.24 |
+16:35:54.2 |
HIP 96078 |
8.09 |
| 2026-06-08 00:00 |
19:32:14.26 |
+16:36:11.2 |
HIP 96078 |
8.10 |
| 2026-06-08 12:00 |
19:32:11.26 |
+16:36:27.8 |
HIP 96078 |
8.19 |
| 2026-06-09 00:00 |
19:32:08.24 |
+16:36:44.2 |
HIP 96078 |
8.34 |
| 2026-06-09 12:00 |
19:32:05.21 |
+16:37:00.4 |
HIP 96078 |
8.55 |
| 2026-06-10 00:00 |
19:32:02.15 |
+16:37:16.3 |
HIP 96078 |
8.83 |
| 2026-06-10 12:00 |
19:31:59.08 |
+16:37:31.9 |
HIP 96078 |
9.16 |
| 2026-06-11 00:00 |
19:31:56.00 |
+16:37:47.3 |
HIP 96078 |
9.53 |
| 2026-06-11 12:00 |
19:31:52.90 |
+16:38:02.4 |
HIP 96078 |
9.96 |
| 2026-06-12 00:00 |
19:31:49.78 |
+16:38:17.3 |
HIP 96078 |
10.42 |
| 2026-06-12 12:00 |
19:31:46.65 |
+16:38:31.9 |
HIP 96078 |
10.91 |
| 2026-06-13 00:00 |
19:31:43.50 |
+16:38:46.3 |
HIP 96078 |
11.44 |
| 2026-06-13 12:00 |
19:31:40.34 |
+16:39:00.4 |
HIP 96078 |
11.99 |
| 2026-06-14 00:00 |
19:31:37.16 |
+16:39:14.2 |
HIP 96078 |
12.57 |
| 2026-06-14 12:00 |
19:31:33.96 |
+16:39:27.8 |
HIP 96078 |
13.17 |
| 2026-06-15 00:00 |
19:31:30.75 |
+16:39:41.1 |
HIP 96078 |
13.79 |
| 2026-06-15 12:00 |
19:31:27.53 |
+16:39:54.1 |
HIP 96078 |
14.42 |
| 2026-06-16 00:00 |
19:31:24.29 |
+16:40:06.9 |
HIP 95927 |
14.88 |
| 2026-06-16 12:00 |
19:31:21.04 |
+16:40:19.4 |
HIP 95927 |
14.12 |
| 2026-06-17 00:00 |
19:31:17.78 |
+16:40:31.6 |
HIP 95927 |
13.35 |
| 2026-06-17 12:00 |
19:31:14.50 |
+16:40:43.6 |
HIP 95927 |
12.60 |
| 2026-06-18 00:00 |
19:31:11.21 |
+16:40:55.3 |
HIP 95927 |
11.85 |
| 2026-06-18 12:00 |
19:31:07.91 |
+16:41:06.7 |
HIP 95915 |
11.04 |
| 2026-06-19 00:00 |
19:31:04.59 |
+16:41:17.9 |
HIP 95915 |
10.23 |
| 2026-06-19 12:00 |
19:31:01.27 |
+16:41:28.7 |
HIP 95915 |
9.41 |
| 2026-06-20 00:00 |
19:30:57.93 |
+16:41:39.4 |
HIP 95915 |
8.60 |
| 2026-06-20 12:00 |
19:30:54.57 |
+16:41:49.7 |
HIP 95915 |
7.78 |
| 2026-06-21 00:00 |
19:30:51.21 |
+16:41:59.8 |
HIP 95915 |
6.96 |
| 2026-06-21 12:00 |
19:30:47.84 |
+16:42:09.6 |
HIP 95915 |
6.14 |
| 2026-06-22 00:00 |
19:30:44.45 |
+16:42:19.1 |
HIP 95915 |
5.32 |