| Parameter |
Value |
| Designation |
C/1990 K1 (Levy) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1990-10-24T16:24:53.331840Z |
| Orbit solution date (soln_date, UTC) |
2023-08-19T20:42:31Z |
| Obs used |
666 |
| NEO |
- |
| M1 |
4.600 |
| K1 |
9.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1990-10-29.0000000 |
| e |
1.00058309 |
| q (au) |
0.938738 |
| a (au) |
-1609.945375 |
| i (deg) |
131.583977 |
| Ω (om, deg) |
139.364097 |
| ω (w, deg) |
242.666331 |
| M (ma, deg) |
0.000066 |
Magnitude
Scatter + Global Linear
$$
M_a = (4.561 + 3.402\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
4.561 |
| n |
3.402 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.916 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 1990-05-20 |
1990-07-17 |
+0.5609 |
-0.382 |
| 1990-07-17 |
1990-10-23 |
-2.7924 |
+0.454 |
| 1990-10-24 |
1991-04-15 |
+1.4645 |
+0.190 |
| 1991-04-15 |
1991-11-07 |
-5.2198 |
+3.605 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
07:13:04.65 |
+56:08:29.4 |
HIP 34754 |
15.51 |
| 2026-05-12 12:00 |
07:13:06.50 |
+56:08:14.9 |
HIP 34754 |
15.86 |
| 2026-05-13 00:00 |
07:13:08.37 |
+56:08:00.4 |
HIP 34754 |
16.22 |
| 2026-05-13 12:00 |
07:13:10.27 |
+56:07:45.9 |
HIP 34754 |
16.57 |
| 2026-05-14 00:00 |
07:13:12.20 |
+56:07:31.5 |
HIP 34754 |
16.93 |
| 2026-05-14 12:00 |
07:13:14.14 |
+56:07:17.2 |
HIP 34754 |
17.29 |
| 2026-05-15 00:00 |
07:13:16.11 |
+56:07:02.9 |
HIP 34754 |
17.66 |
| 2026-05-15 12:00 |
07:13:18.10 |
+56:06:48.7 |
HIP 34754 |
18.02 |
| 2026-05-16 00:00 |
07:13:20.11 |
+56:06:34.6 |
HIP 34754 |
18.39 |
| 2026-05-16 12:00 |
07:13:22.14 |
+56:06:20.5 |
HIP 34866 |
18.65 |
| 2026-05-17 00:00 |
07:13:24.20 |
+56:06:06.5 |
HIP 34866 |
18.49 |
| 2026-05-17 12:00 |
07:13:26.28 |
+56:05:52.5 |
HIP 34866 |
18.35 |
| 2026-05-18 00:00 |
07:13:28.38 |
+56:05:38.7 |
HIP 34866 |
18.21 |
| 2026-05-18 12:00 |
07:13:30.50 |
+56:05:24.9 |
HIP 34866 |
18.07 |
| 2026-05-19 00:00 |
07:13:32.65 |
+56:05:11.1 |
HIP 34866 |
17.95 |
| 2026-05-19 12:00 |
07:13:34.81 |
+56:04:57.4 |
HIP 34866 |
17.84 |
| 2026-05-20 00:00 |
07:13:37.00 |
+56:04:43.9 |
HIP 34866 |
17.74 |
| 2026-05-20 12:00 |
07:13:39.20 |
+56:04:30.3 |
HIP 34866 |
17.64 |
| 2026-05-21 00:00 |
07:13:41.43 |
+56:04:16.9 |
HIP 34866 |
17.56 |
| 2026-05-21 12:00 |
07:13:43.68 |
+56:04:03.5 |
HIP 34866 |
17.49 |
| 2026-05-22 00:00 |
07:13:45.95 |
+56:03:50.2 |
HIP 34866 |
17.42 |
| 2026-05-22 12:00 |
07:13:48.23 |
+56:03:37.0 |
HIP 34866 |
17.37 |
| 2026-05-23 00:00 |
07:13:50.54 |
+56:03:23.8 |
HIP 34866 |
17.33 |
| 2026-05-23 12:00 |
07:13:52.87 |
+56:03:10.8 |
HIP 34866 |
17.30 |
| 2026-05-24 00:00 |
07:13:55.22 |
+56:02:57.8 |
HIP 34866 |
17.28 |
| 2026-05-24 12:00 |
07:13:57.58 |
+56:02:44.9 |
HIP 34866 |
17.28 |
| 2026-05-25 00:00 |
07:13:59.97 |
+56:02:32.0 |
HIP 34866 |
17.28 |
| 2026-05-25 12:00 |
07:14:02.37 |
+56:02:19.3 |
HIP 34866 |
17.30 |
| 2026-05-26 00:00 |
07:14:04.79 |
+56:02:06.6 |
HIP 34866 |
17.33 |
| 2026-05-26 12:00 |
07:14:07.23 |
+56:01:54.0 |
HIP 34866 |
17.37 |
| 2026-05-27 00:00 |
07:14:09.69 |
+56:01:41.5 |
HIP 34866 |
17.42 |
| 2026-05-27 12:00 |
07:14:12.17 |
+56:01:29.1 |
HIP 34866 |
17.48 |
| 2026-05-28 00:00 |
07:14:14.67 |
+56:01:16.8 |
HIP 34869 |
17.56 |
| 2026-05-28 12:00 |
07:14:17.18 |
+56:01:04.5 |
HIP 34869 |
17.63 |
| 2026-05-29 00:00 |
07:14:19.71 |
+56:00:52.3 |
HIP 34869 |
17.72 |
| 2026-05-29 12:00 |
07:14:22.26 |
+56:00:40.3 |
HIP 34869 |
17.83 |
| 2026-05-30 00:00 |
07:14:24.83 |
+56:00:28.3 |
HIP 34869 |
17.94 |
| 2026-05-30 12:00 |
07:14:27.41 |
+56:00:16.4 |
HIP 34869 |
18.06 |
| 2026-05-31 00:00 |
07:14:30.01 |
+56:00:04.5 |
HIP 34869 |
18.20 |
| 2026-05-31 12:00 |
07:14:32.62 |
+55:59:52.8 |
HIP 34869 |
18.35 |
| 2026-06-01 00:00 |
07:14:35.26 |
+55:59:41.2 |
HIP 34869 |
18.51 |
| 2026-06-01 12:00 |
07:14:37.91 |
+55:59:29.6 |
HIP 34869 |
18.67 |
| 2026-06-02 00:00 |
07:14:40.57 |
+55:59:18.2 |
HIP 34869 |
18.85 |