| Parameter |
Value |
| Designation |
C/2012 Y3 (McNaught) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2012-08-25T20:18:44.000640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:30Z |
| Obs used |
150 |
| NEO |
- |
| M1 |
12.900 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-02-01.0000000 |
| e |
0.93994217 |
| q (au) |
1.764843 |
| a (au) |
29.385733 |
| i (deg) |
73.231907 |
| Ω (om, deg) |
122.707962 |
| ω (w, deg) |
235.694296 |
| M (ma, deg) |
0.984727 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.507 + 5.732\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.507 |
| n |
5.732 |
| gf |
0.999 |
| 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) |
| 2026-06-01 00:00 |
09:44:57.08 |
+47:42:51.5 |
HIP 47618 |
27.46 |
| 2026-06-01 12:00 |
09:44:59.08 |
+47:42:15.1 |
HIP 47618 |
27.47 |
| 2026-06-02 00:00 |
09:45:01.13 |
+47:41:38.7 |
HIP 47618 |
27.50 |
| 2026-06-02 12:00 |
09:45:03.23 |
+47:41:02.2 |
HIP 47618 |
27.56 |
| 2026-06-03 00:00 |
09:45:05.37 |
+47:40:25.7 |
HIP 47618 |
27.64 |
| 2026-06-03 12:00 |
09:45:07.56 |
+47:39:49.2 |
HIP 47618 |
27.75 |
| 2026-06-04 00:00 |
09:45:09.80 |
+47:39:12.6 |
HIP 47618 |
27.88 |
| 2026-06-04 12:00 |
09:45:12.08 |
+47:38:36.0 |
HIP 47618 |
28.04 |
| 2026-06-05 00:00 |
09:45:14.41 |
+47:37:59.4 |
HIP 47618 |
28.22 |
| 2026-06-05 12:00 |
09:45:16.79 |
+47:37:22.8 |
HIP 48008 |
28.08 |
| 2026-06-06 00:00 |
09:45:19.21 |
+47:36:46.1 |
HIP 48008 |
27.36 |
| 2026-06-06 12:00 |
09:45:21.67 |
+47:36:09.5 |
HIP 48008 |
26.64 |
| 2026-06-07 00:00 |
09:45:24.18 |
+47:35:32.8 |
HIP 48008 |
25.91 |
| 2026-06-07 12:00 |
09:45:26.74 |
+47:34:56.1 |
HIP 48008 |
25.17 |
| 2026-06-08 00:00 |
09:45:29.33 |
+47:34:19.4 |
HIP 48008 |
24.43 |
| 2026-06-08 12:00 |
09:45:31.98 |
+47:33:42.7 |
HIP 48008 |
23.69 |
| 2026-06-09 00:00 |
09:45:34.67 |
+47:33:06.0 |
HIP 48008 |
22.94 |
| 2026-06-09 12:00 |
09:45:37.40 |
+47:32:29.3 |
HIP 48008 |
22.18 |
| 2026-06-10 00:00 |
09:45:40.18 |
+47:31:52.6 |
HIP 48008 |
21.42 |
| 2026-06-10 12:00 |
09:45:43.00 |
+47:31:15.9 |
HIP 48008 |
20.66 |
| 2026-06-11 00:00 |
09:45:45.86 |
+47:30:39.3 |
HIP 48008 |
19.89 |
| 2026-06-11 12:00 |
09:45:48.77 |
+47:30:02.6 |
HIP 48008 |
19.12 |
| 2026-06-12 00:00 |
09:45:51.72 |
+47:29:25.9 |
HIP 48008 |
18.34 |
| 2026-06-12 12:00 |
09:45:54.71 |
+47:28:49.3 |
HIP 48008 |
17.56 |
| 2026-06-13 00:00 |
09:45:57.74 |
+47:28:12.7 |
HIP 48008 |
16.78 |
| 2026-06-13 12:00 |
09:46:00.82 |
+47:27:36.1 |
HIP 48008 |
15.99 |
| 2026-06-14 00:00 |
09:46:03.94 |
+47:26:59.5 |
HIP 48008 |
15.19 |
| 2026-06-14 12:00 |
09:46:07.10 |
+47:26:22.9 |
HIP 48008 |
14.39 |
| 2026-06-15 00:00 |
09:46:10.31 |
+47:25:46.4 |
HIP 48008 |
13.59 |
| 2026-06-15 12:00 |
09:46:13.55 |
+47:25:09.9 |
HIP 48008 |
12.79 |
| 2026-06-16 00:00 |
09:46:16.84 |
+47:24:33.4 |
HIP 48008 |
11.98 |
| 2026-06-16 12:00 |
09:46:20.16 |
+47:23:57.0 |
HIP 48008 |
11.16 |
| 2026-06-17 00:00 |
09:46:23.53 |
+47:23:20.6 |
HIP 48008 |
10.35 |
| 2026-06-17 12:00 |
09:46:26.94 |
+47:22:44.3 |
HIP 48008 |
9.53 |
| 2026-06-18 00:00 |
09:46:30.39 |
+47:22:08.0 |
HIP 48008 |
8.71 |
| 2026-06-18 12:00 |
09:46:33.87 |
+47:21:31.7 |
HIP 48008 |
7.89 |
| 2026-06-19 00:00 |
09:46:37.40 |
+47:20:55.5 |
HIP 48008 |
7.07 |
| 2026-06-19 12:00 |
09:46:40.97 |
+47:20:19.4 |
HIP 48008 |
6.25 |
| 2026-06-20 00:00 |
09:46:44.57 |
+47:19:43.3 |
HIP 48008 |
5.43 |
| 2026-06-20 12:00 |
09:46:48.21 |
+47:19:07.2 |
HIP 48008 |
4.63 |
| 2026-06-21 00:00 |
09:46:51.89 |
+47:18:31.2 |
HIP 48008 |
3.84 |
| 2026-06-21 12:00 |
09:46:55.61 |
+47:17:55.3 |
HIP 48008 |
3.09 |
| 2026-06-22 00:00 |
09:46:59.37 |
+47:17:19.5 |
HIP 48008 |
2.41 |