| Parameter |
Value |
| Designation |
C/1991 C3 (McNaught-Russell) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1990-10-18T13:20:57.874560Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:41Z |
| Obs used |
42 |
| NEO |
- |
| M1 |
7.100 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1991-06-24.0000000 |
| e |
1.00249603 |
| q (au) |
4.777706 |
| a (au) |
-1914.125633 |
| i (deg) |
113.443762 |
| Ω (om, deg) |
161.705796 |
| ω (w, deg) |
320.929727 |
| M (ma, deg) |
0.002924 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.686 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.686 |
| n |
2.000 |
| gf |
0.998 |
| gb |
-0.502 |
| 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) |
| 2026-06-01 00:00 |
23:13:32.91 |
+65:23:49.5 |
HIP 114769 |
8.67 |
| 2026-06-01 12:00 |
23:13:33.47 |
+65:24:17.3 |
HIP 114769 |
8.54 |
| 2026-06-02 00:00 |
23:13:33.99 |
+65:24:45.1 |
HIP 114769 |
8.43 |
| 2026-06-02 12:00 |
23:13:34.46 |
+65:25:12.9 |
HIP 114769 |
8.35 |
| 2026-06-03 00:00 |
23:13:34.91 |
+65:25:40.6 |
HIP 114769 |
8.31 |
| 2026-06-03 12:00 |
23:13:35.31 |
+65:26:08.4 |
HIP 114769 |
8.29 |
| 2026-06-04 00:00 |
23:13:35.67 |
+65:26:36.1 |
HIP 114769 |
8.30 |
| 2026-06-04 12:00 |
23:13:36.00 |
+65:27:03.8 |
HIP 114769 |
8.34 |
| 2026-06-05 00:00 |
23:13:36.29 |
+65:27:31.6 |
HIP 114769 |
8.41 |
| 2026-06-05 12:00 |
23:13:36.54 |
+65:27:59.2 |
HIP 114769 |
8.51 |
| 2026-06-06 00:00 |
23:13:36.75 |
+65:28:26.9 |
HIP 114769 |
8.64 |
| 2026-06-06 12:00 |
23:13:36.92 |
+65:28:54.6 |
HIP 114769 |
8.79 |
| 2026-06-07 00:00 |
23:13:37.05 |
+65:29:22.2 |
HIP 114769 |
8.97 |
| 2026-06-07 12:00 |
23:13:37.15 |
+65:29:49.8 |
HIP 114769 |
9.17 |
| 2026-06-08 00:00 |
23:13:37.20 |
+65:30:17.4 |
HIP 114769 |
9.39 |
| 2026-06-08 12:00 |
23:13:37.22 |
+65:30:44.9 |
HIP 114769 |
9.63 |
| 2026-06-09 00:00 |
23:13:37.20 |
+65:31:12.4 |
HIP 114769 |
9.89 |
| 2026-06-09 12:00 |
23:13:37.14 |
+65:31:39.9 |
HIP 114769 |
10.17 |
| 2026-06-10 00:00 |
23:13:37.04 |
+65:32:07.4 |
HIP 114769 |
10.46 |
| 2026-06-10 12:00 |
23:13:36.90 |
+65:32:34.8 |
HIP 114769 |
10.77 |
| 2026-06-11 00:00 |
23:13:36.72 |
+65:33:02.2 |
HIP 114769 |
11.09 |
| 2026-06-11 12:00 |
23:13:36.50 |
+65:33:29.5 |
HIP 114769 |
11.42 |
| 2026-06-12 00:00 |
23:13:36.25 |
+65:33:56.8 |
HIP 114769 |
11.76 |
| 2026-06-12 12:00 |
23:13:35.95 |
+65:34:24.0 |
HIP 114769 |
12.11 |
| 2026-06-13 00:00 |
23:13:35.62 |
+65:34:51.2 |
HIP 114769 |
12.48 |
| 2026-06-13 12:00 |
23:13:35.24 |
+65:35:18.3 |
HIP 114769 |
12.84 |
| 2026-06-14 00:00 |
23:13:34.83 |
+65:35:45.4 |
HIP 114769 |
13.22 |
| 2026-06-14 12:00 |
23:13:34.37 |
+65:36:12.5 |
HIP 114769 |
13.60 |
| 2026-06-15 00:00 |
23:13:33.88 |
+65:36:39.4 |
HIP 114769 |
13.99 |
| 2026-06-15 12:00 |
23:13:33.35 |
+65:37:06.3 |
HIP 114769 |
14.38 |
| 2026-06-16 00:00 |
23:13:32.78 |
+65:37:33.2 |
HIP 114769 |
14.78 |
| 2026-06-16 12:00 |
23:13:32.17 |
+65:38:00.0 |
HIP 114769 |
15.18 |
| 2026-06-17 00:00 |
23:13:31.52 |
+65:38:26.7 |
HIP 114769 |
15.59 |
| 2026-06-17 12:00 |
23:13:30.83 |
+65:38:53.4 |
HIP 114769 |
16.00 |
| 2026-06-18 00:00 |
23:13:30.10 |
+65:39:19.9 |
HIP 114769 |
16.41 |
| 2026-06-18 12:00 |
23:13:29.33 |
+65:39:46.5 |
HIP 114769 |
16.83 |
| 2026-06-19 00:00 |
23:13:28.52 |
+65:40:12.9 |
HIP 114769 |
17.25 |
| 2026-06-19 12:00 |
23:13:27.68 |
+65:40:39.3 |
HIP 114769 |
17.67 |
| 2026-06-20 00:00 |
23:13:26.79 |
+65:41:05.5 |
HIP 114769 |
18.09 |
| 2026-06-20 12:00 |
23:13:25.87 |
+65:41:31.7 |
HIP 114769 |
18.52 |
| 2026-06-21 00:00 |
23:13:24.90 |
+65:41:57.9 |
HIP 114769 |
18.95 |
| 2026-06-21 12:00 |
23:13:23.90 |
+65:42:23.9 |
HIP 114769 |
19.37 |
| 2026-06-22 00:00 |
23:13:22.86 |
+65:42:49.8 |
HIP 114769 |
19.80 |