| Parameter |
Value |
| Designation |
89P/Russell 2 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2016-12-14T20:36:28.673280Z |
| Orbit solution date (soln_date, UTC) |
2025-11-13T13:54:38Z |
| Obs used |
648 |
| NEO |
- |
| M1 |
8.200 |
| K1 |
21.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-07-19.0000000 |
| e |
0.40842673 |
| q (au) |
2.220297 |
| a (au) |
3.753208 |
| i (deg) |
12.076267 |
| Ω (om, deg) |
41.443124 |
| ω (w, deg) |
250.178436 |
| M (ma, deg) |
78.773821 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.324 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.324 |
| n |
6.000 |
| gf |
0.856 |
| gb |
-0.758 |
| k |
0.985 |
| δ90 |
1.000 |
| 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) |
| 2026-09-20 00:00 |
06:25:01.69 |
+31:25:00.8 |
HIP 30697 |
33.13 |
| 2026-09-20 12:00 |
06:25:14.81 |
+31:26:00.0 |
HIP 30697 |
31.73 |
| 2026-09-21 00:00 |
06:25:27.74 |
+31:26:59.5 |
HIP 30697 |
30.59 |
| 2026-09-21 12:00 |
06:25:40.47 |
+31:27:59.2 |
HIP 30697 |
29.73 |
| 2026-09-22 00:00 |
06:25:53.01 |
+31:28:59.2 |
HIP 30697 |
29.15 |
| 2026-09-22 12:00 |
06:26:05.36 |
+31:29:59.5 |
HIP 30697 |
28.88 |
| 2026-09-23 00:00 |
06:26:17.50 |
+31:31:00.1 |
HIP 30697 |
28.89 |
| 2026-09-23 12:00 |
06:26:29.45 |
+31:32:00.9 |
HIP 30697 |
29.18 |
| 2026-09-24 00:00 |
06:26:41.19 |
+31:33:02.1 |
HIP 30697 |
29.74 |
| 2026-09-24 12:00 |
06:26:52.74 |
+31:34:03.5 |
HIP 30697 |
30.54 |
| 2026-09-25 00:00 |
06:27:04.09 |
+31:35:05.2 |
HIP 30697 |
31.54 |
| 2026-09-25 12:00 |
06:27:15.23 |
+31:36:07.3 |
HIP 30697 |
32.73 |
| 2026-09-26 00:00 |
06:27:26.16 |
+31:37:09.6 |
HIP 30816 |
33.56 |
| 2026-09-26 12:00 |
06:27:36.90 |
+31:38:12.2 |
HIP 30816 |
31.75 |
| 2026-09-27 00:00 |
06:27:47.42 |
+31:39:15.1 |
HIP 30816 |
30.04 |
| 2026-09-27 12:00 |
06:27:57.74 |
+31:40:18.3 |
HIP 30816 |
28.45 |
| 2026-09-28 00:00 |
06:28:07.85 |
+31:41:21.8 |
HIP 30816 |
26.99 |
| 2026-09-28 12:00 |
06:28:17.75 |
+31:42:25.6 |
HIP 30816 |
25.67 |
| 2026-09-29 00:00 |
06:28:27.44 |
+31:43:29.6 |
HIP 30816 |
24.50 |
| 2026-09-29 12:00 |
06:28:36.92 |
+31:44:34.0 |
HIP 30816 |
23.50 |
| 2026-09-30 00:00 |
06:28:46.19 |
+31:45:38.7 |
HIP 30816 |
22.66 |
| 2026-09-30 12:00 |
06:28:55.24 |
+31:46:43.7 |
HIP 30816 |
22.01 |
| 2026-10-01 00:00 |
06:29:04.07 |
+31:47:49.0 |
HIP 30816 |
21.54 |
| 2026-10-01 12:00 |
06:29:12.69 |
+31:48:54.6 |
HIP 30816 |
21.26 |
| 2026-10-02 00:00 |
06:29:21.09 |
+31:50:00.5 |
HIP 30816 |
21.16 |
| 2026-10-02 12:00 |
06:29:29.27 |
+31:51:06.8 |
HIP 30816 |
21.23 |
| 2026-10-03 00:00 |
06:29:37.23 |
+31:52:13.3 |
HIP 30816 |
21.47 |
| 2026-10-03 12:00 |
06:29:44.96 |
+31:53:20.1 |
HIP 30816 |
21.85 |
| 2026-10-04 00:00 |
06:29:52.48 |
+31:54:27.2 |
HIP 30816 |
22.36 |
| 2026-10-04 12:00 |
06:29:59.77 |
+31:55:34.7 |
HIP 30969 |
22.96 |
| 2026-10-05 00:00 |
06:30:06.83 |
+31:56:42.4 |
HIP 30969 |
21.85 |
| 2026-10-05 12:00 |
06:30:13.67 |
+31:57:50.5 |
HIP 30969 |
20.84 |
| 2026-10-06 00:00 |
06:30:20.27 |
+31:58:58.8 |
HIP 31104 |
19.57 |
| 2026-10-06 12:00 |
06:30:26.65 |
+32:00:07.5 |
HIP 31104 |
17.81 |
| 2026-10-07 00:00 |
06:30:32.80 |
+32:01:16.4 |
HIP 31104 |
16.09 |
| 2026-10-07 12:00 |
06:30:38.72 |
+32:02:25.7 |
HIP 31104 |
14.41 |
| 2026-10-08 00:00 |
06:30:44.40 |
+32:03:35.2 |
HIP 31104 |
12.78 |
| 2026-10-08 12:00 |
06:30:49.85 |
+32:04:45.1 |
HIP 31104 |
11.21 |
| 2026-10-09 00:00 |
06:30:55.06 |
+32:05:55.2 |
HIP 31104 |
9.70 |
| 2026-10-09 12:00 |
06:31:00.04 |
+32:07:05.7 |
HIP 31104 |
8.27 |
| 2026-10-10 00:00 |
06:31:04.78 |
+32:08:16.4 |
HIP 31104 |
6.96 |
| 2026-10-10 12:00 |
06:31:09.28 |
+32:09:27.4 |
HIP 31104 |
5.82 |
| 2026-10-11 00:00 |
06:31:13.55 |
+32:10:38.8 |
HIP 31104 |
4.94 |