C/1989 Y2 (McKenzie-Russell)
| Parameter |
Value |
| Designation |
C/1989 Y2 (McKenzie-Russell) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1989-11-07T16:28:56.971200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:38Z |
| Obs used |
45 |
| NEO |
- |
| M1 |
10.000 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1989-12-30.0000000 |
| e |
0.99999649 |
| q (au) |
1.975796 |
| a (au) |
562869.874478 |
| i (deg) |
160.336275 |
| Ω (om, deg) |
293.896265 |
| ω (w, deg) |
191.736136 |
| M (ma, deg) |
0.000000 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.266 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.266 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.972 |
| 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) |
| 2026-02-03 00:00 |
20:23:09.32 |
-22:26:28.0 |
HIP 100637 |
28.81 |
| 2026-02-03 12:00 |
20:23:11.30 |
-22:26:21.4 |
HIP 100637 |
28.45 |
| 2026-02-04 00:00 |
20:23:13.28 |
-22:26:14.8 |
HIP 100637 |
28.11 |
| 2026-02-04 12:00 |
20:23:15.25 |
-22:26:08.2 |
HIP 100637 |
27.76 |
| 2026-02-05 00:00 |
20:23:17.22 |
-22:26:01.7 |
HIP 100637 |
27.42 |
| 2026-02-05 12:00 |
20:23:19.19 |
-22:25:55.2 |
HIP 100637 |
27.09 |
| 2026-02-06 00:00 |
20:23:21.15 |
-22:25:48.7 |
HIP 100637 |
26.76 |
| 2026-02-06 12:00 |
20:23:23.11 |
-22:25:42.2 |
HIP 100637 |
26.43 |
| 2026-02-07 00:00 |
20:23:25.07 |
-22:25:35.8 |
HIP 100637 |
26.11 |
| 2026-02-07 12:00 |
20:23:27.02 |
-22:25:29.3 |
HIP 100637 |
25.79 |
| 2026-02-08 00:00 |
20:23:28.96 |
-22:25:23.0 |
HIP 100637 |
25.48 |
| 2026-02-08 12:00 |
20:23:30.90 |
-22:25:16.6 |
HIP 100637 |
25.18 |
| 2026-02-09 00:00 |
20:23:32.84 |
-22:25:10.3 |
HIP 100637 |
24.88 |
| 2026-02-09 12:00 |
20:23:34.77 |
-22:25:04.0 |
HIP 100637 |
24.59 |
| 2026-02-10 00:00 |
20:23:36.69 |
-22:24:57.7 |
HIP 100637 |
24.30 |
| 2026-02-10 12:00 |
20:23:38.61 |
-22:24:51.4 |
HIP 100637 |
24.02 |
| 2026-02-11 00:00 |
20:23:40.53 |
-22:24:45.2 |
HIP 100637 |
23.75 |
| 2026-02-11 12:00 |
20:23:42.44 |
-22:24:39.0 |
HIP 100637 |
23.48 |
| 2026-02-12 00:00 |
20:23:44.34 |
-22:24:32.9 |
HIP 100637 |
23.22 |
| 2026-02-12 12:00 |
20:23:46.24 |
-22:24:26.7 |
HIP 100637 |
22.97 |
| 2026-02-13 00:00 |
20:23:48.13 |
-22:24:20.7 |
HIP 100637 |
22.72 |
| 2026-02-13 12:00 |
20:23:50.02 |
-22:24:14.6 |
HIP 100637 |
22.48 |
| 2026-02-14 00:00 |
20:23:51.90 |
-22:24:08.6 |
HIP 100637 |
22.25 |
| 2026-02-14 12:00 |
20:23:53.77 |
-22:24:02.6 |
HIP 100637 |
22.03 |
| 2026-02-15 00:00 |
20:23:55.63 |
-22:23:56.6 |
HIP 100637 |
21.81 |
| 2026-02-15 12:00 |
20:23:57.49 |
-22:23:50.7 |
HIP 100637 |
21.60 |
| 2026-02-16 00:00 |
20:23:59.35 |
-22:23:44.8 |
HIP 100637 |
21.40 |
| 2026-02-16 12:00 |
20:24:01.19 |
-22:23:38.9 |
HIP 100637 |
21.21 |
| 2026-02-17 00:00 |
20:24:03.03 |
-22:23:33.1 |
HIP 100637 |
21.02 |
| 2026-02-17 12:00 |
20:24:04.86 |
-22:23:27.3 |
HIP 100637 |
20.85 |
| 2026-02-18 00:00 |
20:24:06.68 |
-22:23:21.6 |
HIP 100637 |
20.68 |
| 2026-02-18 12:00 |
20:24:08.50 |
-22:23:15.8 |
HIP 100637 |
20.52 |
| 2026-02-19 00:00 |
20:24:10.31 |
-22:23:10.2 |
HIP 100637 |
20.37 |
| 2026-02-19 12:00 |
20:24:12.11 |
-22:23:04.5 |
HIP 100637 |
20.23 |
| 2026-02-20 00:00 |
20:24:13.90 |
-22:22:58.9 |
HIP 100637 |
20.10 |
| 2026-02-20 12:00 |
20:24:15.68 |
-22:22:53.4 |
HIP 100637 |
19.98 |
| 2026-02-21 00:00 |
20:24:17.45 |
-22:22:47.8 |
HIP 100637 |
19.86 |
| 2026-02-21 12:00 |
20:24:19.22 |
-22:22:42.3 |
HIP 100637 |
19.76 |
| 2026-02-22 00:00 |
20:24:20.98 |
-22:22:36.9 |
HIP 100637 |
19.66 |
| 2026-02-22 12:00 |
20:24:22.73 |
-22:22:31.5 |
HIP 100637 |
19.57 |
| 2026-02-23 00:00 |
20:24:24.47 |
-22:22:26.1 |
HIP 100637 |
19.49 |
| 2026-02-23 12:00 |
20:24:26.20 |
-22:22:20.8 |
HIP 100637 |
19.43 |
| 2026-02-24 00:00 |
20:24:27.92 |
-22:22:15.5 |
HIP 100637 |
19.37 |