| Parameter |
Value |
| Designation |
91P/Russell 3 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2005-06-27T02:09:49.521600Z |
| Orbit solution date (soln_date, UTC) |
2021-09-07T13:51:26Z |
| Obs used |
337 |
| NEO |
- |
| M1 |
7.700 |
| K1 |
21.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-04-19.0000000 |
| e |
0.33022414 |
| q (au) |
2.605665 |
| a (au) |
3.890354 |
| i (deg) |
14.092166 |
| Ω (om, deg) |
247.895980 |
| ω (w, deg) |
354.865752 |
| M (ma, deg) |
131.902421 |
Magnitude
Scatter + Global Linear
$$
M_a = (17.424 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
17.424 |
| n |
2.000 |
| gf |
0.834 |
| gb |
-0.704 |
| k |
0.891 |
| δ90 |
2.146 |
| 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) |
| 2026-05-12 00:00 |
06:35:50.67 |
+12:49:39.5 |
HIP 31427 |
14.26 |
| 2026-05-12 12:00 |
06:36:14.98 |
+12:49:31.6 |
HIP 31427 |
19.03 |
| 2026-05-13 00:00 |
06:36:39.38 |
+12:49:23.1 |
HIP 31427 |
24.32 |
| 2026-05-13 12:00 |
06:37:03.87 |
+12:49:14.0 |
HIP 31755 |
22.28 |
| 2026-05-14 00:00 |
06:37:28.46 |
+12:49:04.3 |
HIP 31755 |
16.44 |
| 2026-05-14 12:00 |
06:37:53.14 |
+12:48:54.0 |
HIP 31755 |
10.75 |
| 2026-05-15 00:00 |
06:38:17.92 |
+12:48:43.1 |
HIP 31755 |
5.74 |
| 2026-05-15 12:00 |
06:38:42.79 |
+12:48:31.5 |
HIP 31755 |
4.85 |
| 2026-05-16 00:00 |
06:39:07.75 |
+12:48:19.4 |
HIP 31755 |
9.38 |
| 2026-05-16 12:00 |
06:39:32.80 |
+12:48:06.6 |
HIP 31876 |
11.45 |
| 2026-05-17 00:00 |
06:39:57.94 |
+12:47:53.2 |
HIP 31876 |
11.36 |
| 2026-05-17 12:00 |
06:40:23.17 |
+12:47:39.2 |
HIP 31876 |
14.23 |
| 2026-05-18 00:00 |
06:40:48.48 |
+12:47:24.5 |
HIP 31915 |
17.89 |
| 2026-05-18 12:00 |
06:41:13.88 |
+12:47:09.3 |
HIP 31915 |
21.87 |
| 2026-05-19 00:00 |
06:41:39.37 |
+12:46:53.3 |
HIP 31915 |
26.72 |
| 2026-05-19 12:00 |
06:42:04.94 |
+12:46:36.8 |
HIP 31915 |
32.07 |
| 2026-05-20 00:00 |
06:42:30.59 |
+12:46:19.6 |
HIP 32249 |
34.86 |
| 2026-05-20 12:00 |
06:42:56.33 |
+12:46:01.8 |
HIP 32249 |
31.63 |
| 2026-05-21 00:00 |
06:43:22.15 |
+12:45:43.4 |
HIP 32362 |
29.23 |
| 2026-05-21 12:00 |
06:43:48.04 |
+12:45:24.3 |
HIP 32362 |
23.34 |
| 2026-05-22 00:00 |
06:44:14.02 |
+12:45:04.5 |
HIP 32362 |
17.73 |
| 2026-05-22 12:00 |
06:44:40.07 |
+12:44:44.2 |
HIP 32362 |
12.82 |
| 2026-05-23 00:00 |
06:45:06.21 |
+12:44:23.2 |
HIP 32362 |
9.77 |
| 2026-05-23 12:00 |
06:45:32.41 |
+12:44:01.5 |
HIP 32404 |
5.83 |
| 2026-05-24 00:00 |
06:45:58.70 |
+12:43:39.2 |
HIP 32404 |
2.32 |
| 2026-05-24 12:00 |
06:46:25.06 |
+12:43:16.2 |
HIP 32404 |
7.71 |
| 2026-05-25 00:00 |
06:46:51.49 |
+12:42:52.6 |
HIP 32404 |
14.03 |
| 2026-05-25 12:00 |
06:47:18.00 |
+12:42:28.3 |
HIP 32404 |
20.45 |
| 2026-05-26 00:00 |
06:47:44.57 |
+12:42:03.4 |
HIP 32660 |
16.79 |
| 2026-05-26 12:00 |
06:48:11.22 |
+12:41:37.9 |
HIP 32660 |
11.27 |
| 2026-05-27 00:00 |
06:48:37.94 |
+12:41:11.6 |
HIP 32660 |
7.55 |
| 2026-05-27 12:00 |
06:49:04.73 |
+12:40:44.8 |
HIP 32660 |
8.50 |
| 2026-05-28 00:00 |
06:49:31.59 |
+12:40:17.2 |
HIP 32660 |
13.18 |
| 2026-05-28 12:00 |
06:49:58.52 |
+12:39:49.0 |
HIP 32660 |
19.02 |
| 2026-05-29 00:00 |
06:50:25.51 |
+12:39:20.2 |
HIP 32660 |
25.25 |
| 2026-05-29 12:00 |
06:50:52.57 |
+12:38:50.7 |
HIP 32969 |
29.62 |
| 2026-05-30 00:00 |
06:51:19.70 |
+12:38:20.5 |
HIP 32969 |
25.96 |
| 2026-05-30 12:00 |
06:51:46.89 |
+12:37:49.7 |
HIP 32969 |
23.64 |
| 2026-05-31 00:00 |
06:52:14.15 |
+12:37:18.1 |
HIP 32969 |
23.06 |
| 2026-05-31 12:00 |
06:52:41.47 |
+12:36:46.0 |
HIP 32969 |
24.36 |
| 2026-06-01 00:00 |
06:53:08.85 |
+12:36:13.1 |
HIP 33204 |
23.84 |
| 2026-06-01 12:00 |
06:53:36.29 |
+12:35:39.6 |
HIP 33204 |
17.51 |
| 2026-06-02 00:00 |
06:54:03.80 |
+12:35:05.4 |
HIP 33204 |
11.62 |