| Parameter |
Value |
| Designation |
C/1989 Y1 (Skorichenko-George) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1990-04-11T22:18:59.575680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:38Z |
| Obs used |
106 |
| NEO |
- |
| M1 |
5.300 |
| K1 |
12.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1990-02-24.0000000 |
| e |
1.00030135 |
| q (au) |
1.569168 |
| a (au) |
-5207.172639 |
| i (deg) |
59.365874 |
| Ω (om, deg) |
280.009427 |
| ω (w, deg) |
137.833282 |
| M (ma, deg) |
-0.000123 |
Magnitude
Scatter + Global Linear
$$
M_a = (4.464 + 4.016\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
4.464 |
| n |
4.016 |
| gf |
1.000 |
| gb |
-1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1988-06-13 |
1989-12-28 |
+1.3205 |
-0.610 |
| 1989-12-28 |
1990-04-11 |
-4.1211 |
+0.921 |
| 1990-04-12 |
1991-03-18 |
+3.8685 |
+0.256 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
13:58:35.37 |
-66:08:08.7 |
HIP 68455 |
15.98 |
| 2026-06-01 12:00 |
13:58:31.92 |
-66:07:49.0 |
HIP 68455 |
16.45 |
| 2026-06-02 00:00 |
13:58:28.50 |
-66:07:29.2 |
HIP 68455 |
16.92 |
| 2026-06-02 12:00 |
13:58:25.10 |
-66:07:09.2 |
HIP 68455 |
17.38 |
| 2026-06-03 00:00 |
13:58:21.73 |
-66:06:49.2 |
HIP 68455 |
17.85 |
| 2026-06-03 12:00 |
13:58:18.39 |
-66:06:29.0 |
HIP 68455 |
18.31 |
| 2026-06-04 00:00 |
13:58:15.07 |
-66:06:08.7 |
HIP 68270 |
18.19 |
| 2026-06-04 12:00 |
13:58:11.78 |
-66:05:48.3 |
HIP 68270 |
17.88 |
| 2026-06-05 00:00 |
13:58:08.52 |
-66:05:27.7 |
HIP 68270 |
17.58 |
| 2026-06-05 12:00 |
13:58:05.28 |
-66:05:07.0 |
HIP 68270 |
17.29 |
| 2026-06-06 00:00 |
13:58:02.08 |
-66:04:46.3 |
HIP 68270 |
17.00 |
| 2026-06-06 12:00 |
13:57:58.90 |
-66:04:25.4 |
HIP 68270 |
16.72 |
| 2026-06-07 00:00 |
13:57:55.75 |
-66:04:04.3 |
HIP 68270 |
16.44 |
| 2026-06-07 12:00 |
13:57:52.63 |
-66:03:43.2 |
HIP 68270 |
16.17 |
| 2026-06-08 00:00 |
13:57:49.53 |
-66:03:22.0 |
HIP 68270 |
15.91 |
| 2026-06-08 12:00 |
13:57:46.47 |
-66:03:00.6 |
HIP 68270 |
15.66 |
| 2026-06-09 00:00 |
13:57:43.44 |
-66:02:39.2 |
HIP 68270 |
15.41 |
| 2026-06-09 12:00 |
13:57:40.43 |
-66:02:17.6 |
HIP 68270 |
15.17 |
| 2026-06-10 00:00 |
13:57:37.46 |
-66:01:56.0 |
HIP 68270 |
14.94 |
| 2026-06-10 12:00 |
13:57:34.51 |
-66:01:34.2 |
HIP 68270 |
14.72 |
| 2026-06-11 00:00 |
13:57:31.60 |
-66:01:12.3 |
HIP 68270 |
14.51 |
| 2026-06-11 12:00 |
13:57:28.71 |
-66:00:50.4 |
HIP 68270 |
14.31 |
| 2026-06-12 00:00 |
13:57:25.86 |
-66:00:28.3 |
HIP 68270 |
14.12 |
| 2026-06-12 12:00 |
13:57:23.03 |
-66:00:06.1 |
HIP 68270 |
13.93 |
| 2026-06-13 00:00 |
13:57:20.24 |
-65:59:43.9 |
HIP 68270 |
13.76 |
| 2026-06-13 12:00 |
13:57:17.48 |
-65:59:21.6 |
HIP 68270 |
13.60 |
| 2026-06-14 00:00 |
13:57:14.75 |
-65:58:59.1 |
HIP 68270 |
13.45 |
| 2026-06-14 12:00 |
13:57:12.06 |
-65:58:36.6 |
HIP 68270 |
13.32 |
| 2026-06-15 00:00 |
13:57:09.39 |
-65:58:14.0 |
HIP 68270 |
13.19 |
| 2026-06-15 12:00 |
13:57:06.76 |
-65:57:51.3 |
HIP 68270 |
13.08 |
| 2026-06-16 00:00 |
13:57:04.16 |
-65:57:28.5 |
HIP 68270 |
12.98 |
| 2026-06-16 12:00 |
13:57:01.59 |
-65:57:05.7 |
HIP 68270 |
12.89 |
| 2026-06-17 00:00 |
13:56:59.05 |
-65:56:42.7 |
HIP 68270 |
12.81 |
| 2026-06-17 12:00 |
13:56:56.55 |
-65:56:19.7 |
HIP 68270 |
12.75 |
| 2026-06-18 00:00 |
13:56:54.08 |
-65:55:56.7 |
HIP 68270 |
12.70 |
| 2026-06-18 12:00 |
13:56:51.64 |
-65:55:33.5 |
HIP 68270 |
12.66 |
| 2026-06-19 00:00 |
13:56:49.24 |
-65:55:10.3 |
HIP 68270 |
12.64 |
| 2026-06-19 12:00 |
13:56:46.87 |
-65:54:47.0 |
HIP 68270 |
12.63 |
| 2026-06-20 00:00 |
13:56:44.53 |
-65:54:23.6 |
HIP 68270 |
12.63 |
| 2026-06-20 12:00 |
13:56:42.23 |
-65:54:00.2 |
HIP 68270 |
12.65 |
| 2026-06-21 00:00 |
13:56:39.96 |
-65:53:36.7 |
HIP 68270 |
12.68 |
| 2026-06-21 12:00 |
13:56:37.73 |
-65:53:13.1 |
HIP 68270 |
12.72 |
| 2026-06-22 00:00 |
13:56:35.53 |
-65:52:49.5 |
HIP 68270 |
12.78 |