| Parameter |
Value |
| Designation |
C/1991 Q1 (McNaught-Russell) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1992-05-03T10:52:23.122560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:41Z |
| Obs used |
29 |
| NEO |
- |
| M1 |
5.000 |
| K1 |
15.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1992-08-12.0000000 |
| e |
0.99448867 |
| q (au) |
3.193967 |
| a (au) |
579.527657 |
| i (deg) |
90.506206 |
| Ω (om, deg) |
120.462895 |
| ω (w, deg) |
257.232969 |
| M (ma, deg) |
0.007103 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.015 + 2.500\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.015 |
| n |
2.500 |
| gf |
0.998 |
| gb |
-0.876 |
| k |
0.968 |
| δ90 |
9.995 |
| 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 |
09:46:10.23 |
+67:00:19.6 |
HIP 47837 |
6.68 |
| 2026-07-29 12:00 |
09:46:15.11 |
+67:00:07.4 |
HIP 47837 |
7.12 |
| 2026-07-30 00:00 |
09:46:20.00 |
+66:59:55.3 |
HIP 47837 |
7.57 |
| 2026-07-30 12:00 |
09:46:24.90 |
+66:59:43.4 |
HIP 47837 |
8.03 |
| 2026-07-31 00:00 |
09:46:29.81 |
+66:59:31.7 |
HIP 47837 |
8.50 |
| 2026-07-31 12:00 |
09:46:34.73 |
+66:59:20.1 |
HIP 47837 |
8.97 |
| 2026-08-01 00:00 |
09:46:39.66 |
+66:59:08.7 |
HIP 47837 |
9.45 |
| 2026-08-01 12:00 |
09:46:44.60 |
+66:58:57.6 |
HIP 47837 |
9.94 |
| 2026-08-02 00:00 |
09:46:49.56 |
+66:58:46.5 |
HIP 47837 |
10.43 |
| 2026-08-02 12:00 |
09:46:54.52 |
+66:58:35.7 |
HIP 47837 |
10.92 |
| 2026-08-03 00:00 |
09:46:59.49 |
+66:58:25.0 |
HIP 47837 |
11.41 |
| 2026-08-03 12:00 |
09:47:04.47 |
+66:58:14.6 |
HIP 47837 |
11.91 |
| 2026-08-04 00:00 |
09:47:09.46 |
+66:58:04.3 |
HIP 47837 |
12.41 |
| 2026-08-04 12:00 |
09:47:14.46 |
+66:57:54.2 |
HIP 47837 |
12.92 |
| 2026-08-05 00:00 |
09:47:19.47 |
+66:57:44.3 |
HIP 47837 |
13.42 |
| 2026-08-05 12:00 |
09:47:24.49 |
+66:57:34.5 |
HIP 47837 |
13.93 |
| 2026-08-06 00:00 |
09:47:29.51 |
+66:57:25.0 |
HIP 47837 |
14.43 |
| 2026-08-06 12:00 |
09:47:34.54 |
+66:57:15.6 |
HIP 47837 |
14.94 |
| 2026-08-07 00:00 |
09:47:39.58 |
+66:57:06.4 |
HIP 47837 |
15.45 |
| 2026-08-07 12:00 |
09:47:44.62 |
+66:56:57.5 |
HIP 47837 |
15.96 |
| 2026-08-08 00:00 |
09:47:49.67 |
+66:56:48.7 |
HIP 48258 |
16.34 |
| 2026-08-08 12:00 |
09:47:54.73 |
+66:56:40.1 |
HIP 48258 |
15.84 |
| 2026-08-09 00:00 |
09:47:59.79 |
+66:56:31.7 |
HIP 48258 |
15.34 |
| 2026-08-09 12:00 |
09:48:04.86 |
+66:56:23.4 |
HIP 48258 |
14.84 |
| 2026-08-10 00:00 |
09:48:09.94 |
+66:56:15.4 |
HIP 48258 |
14.34 |
| 2026-08-10 12:00 |
09:48:15.01 |
+66:56:07.6 |
HIP 48258 |
13.84 |
| 2026-08-11 00:00 |
09:48:20.10 |
+66:56:00.0 |
HIP 48258 |
13.35 |
| 2026-08-11 12:00 |
09:48:25.19 |
+66:55:52.5 |
HIP 48258 |
12.85 |
| 2026-08-12 00:00 |
09:48:30.28 |
+66:55:45.2 |
HIP 48258 |
12.37 |
| 2026-08-12 12:00 |
09:48:35.37 |
+66:55:38.2 |
HIP 48258 |
11.88 |
| 2026-08-13 00:00 |
09:48:40.47 |
+66:55:31.3 |
HIP 48258 |
11.40 |
| 2026-08-13 12:00 |
09:48:45.57 |
+66:55:24.7 |
HIP 48258 |
10.92 |
| 2026-08-14 00:00 |
09:48:50.68 |
+66:55:18.2 |
HIP 48258 |
10.45 |
| 2026-08-14 12:00 |
09:48:55.78 |
+66:55:12.0 |
HIP 48258 |
9.99 |
| 2026-08-15 00:00 |
09:49:00.89 |
+66:55:05.9 |
HIP 48258 |
9.53 |
| 2026-08-15 12:00 |
09:49:06.00 |
+66:55:00.1 |
HIP 48258 |
9.08 |
| 2026-08-16 00:00 |
09:49:11.12 |
+66:54:54.4 |
HIP 48258 |
8.64 |
| 2026-08-16 12:00 |
09:49:16.23 |
+66:54:49.0 |
HIP 48258 |
8.21 |
| 2026-08-17 00:00 |
09:49:21.34 |
+66:54:43.7 |
HIP 48258 |
7.79 |
| 2026-08-17 12:00 |
09:49:26.45 |
+66:54:38.7 |
HIP 48258 |
7.38 |
| 2026-08-18 00:00 |
09:49:31.57 |
+66:54:33.8 |
HIP 48258 |
6.99 |
| 2026-08-18 12:00 |
09:49:36.68 |
+66:54:29.2 |
HIP 48258 |
6.62 |
| 2026-08-19 00:00 |
09:49:41.79 |
+66:54:24.8 |
HIP 48258 |
6.27 |