C/1983 O1 (Cernis)
| Parameter |
Value |
| Designation |
C/1983 O1 (Cernis) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1983-07-21T04:28:44.451840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:31Z |
| Obs used |
229 |
| NEO |
- |
| M1 |
5.200 |
| K1 |
6.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1984-05-13.0000000 |
| e |
1.00152642 |
| q (au) |
3.317948 |
| a (au) |
-2173.674289 |
| i (deg) |
134.695303 |
| Ω (om, deg) |
209.575905 |
| ω (w, deg) |
186.208578 |
| M (ma, deg) |
0.002887 |
Magnitude
Scatter + Global Linear
$$
M_a = (1.779 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
1.779 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.659 |
| k |
0.800 |
| 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 |
| 1983-07-21 |
1984-04-15 |
+9.7034 |
-4.741 |
| 1984-04-15 |
1988-03-23 |
-8.5603 |
+6.413 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
14:30:22.62 |
-29:30:44.8 |
HIP 70941 |
12.52 |
| 2026-02-03 12:00 |
14:30:22.45 |
-29:30:50.3 |
HIP 70941 |
12.62 |
| 2026-02-04 00:00 |
14:30:22.27 |
-29:30:55.6 |
HIP 70941 |
12.72 |
| 2026-02-04 12:00 |
14:30:22.07 |
-29:31:01.0 |
HIP 70941 |
12.81 |
| 2026-02-05 00:00 |
14:30:21.85 |
-29:31:06.2 |
HIP 70941 |
12.91 |
| 2026-02-05 12:00 |
14:30:21.61 |
-29:31:11.4 |
HIP 70941 |
13.01 |
| 2026-02-06 00:00 |
14:30:21.36 |
-29:31:16.4 |
HIP 70941 |
13.10 |
| 2026-02-06 12:00 |
14:30:21.09 |
-29:31:21.5 |
HIP 70941 |
13.20 |
| 2026-02-07 00:00 |
14:30:20.80 |
-29:31:26.4 |
HIP 70941 |
13.29 |
| 2026-02-07 12:00 |
14:30:20.49 |
-29:31:31.2 |
HIP 70941 |
13.39 |
| 2026-02-08 00:00 |
14:30:20.17 |
-29:31:36.0 |
HIP 70941 |
13.48 |
| 2026-02-08 12:00 |
14:30:19.83 |
-29:31:40.7 |
HIP 70941 |
13.58 |
| 2026-02-09 00:00 |
14:30:19.47 |
-29:31:45.3 |
HIP 70941 |
13.67 |
| 2026-02-09 12:00 |
14:30:19.09 |
-29:31:49.8 |
HIP 70941 |
13.77 |
| 2026-02-10 00:00 |
14:30:18.70 |
-29:31:54.3 |
HIP 70941 |
13.86 |
| 2026-02-10 12:00 |
14:30:18.29 |
-29:31:58.6 |
HIP 70941 |
13.96 |
| 2026-02-11 00:00 |
14:30:17.87 |
-29:32:02.9 |
HIP 70941 |
14.05 |
| 2026-02-11 12:00 |
14:30:17.42 |
-29:32:07.1 |
HIP 70941 |
14.15 |
| 2026-02-12 00:00 |
14:30:16.96 |
-29:32:11.2 |
HIP 70941 |
14.24 |
| 2026-02-12 12:00 |
14:30:16.48 |
-29:32:15.2 |
HIP 70941 |
14.34 |
| 2026-02-13 00:00 |
14:30:15.99 |
-29:32:19.2 |
HIP 70941 |
14.44 |
| 2026-02-13 12:00 |
14:30:15.47 |
-29:32:23.0 |
HIP 70941 |
14.53 |
| 2026-02-14 00:00 |
14:30:14.94 |
-29:32:26.8 |
HIP 70941 |
14.63 |
| 2026-02-14 12:00 |
14:30:14.40 |
-29:32:30.5 |
HIP 70941 |
14.72 |
| 2026-02-15 00:00 |
14:30:13.83 |
-29:32:34.1 |
HIP 70941 |
14.82 |
| 2026-02-15 12:00 |
14:30:13.25 |
-29:32:37.6 |
HIP 70941 |
14.92 |
| 2026-02-16 00:00 |
14:30:12.66 |
-29:32:41.0 |
HIP 70941 |
15.02 |
| 2026-02-16 12:00 |
14:30:12.04 |
-29:32:44.4 |
HIP 70941 |
15.12 |
| 2026-02-17 00:00 |
14:30:11.41 |
-29:32:47.6 |
HIP 70941 |
15.22 |
| 2026-02-17 12:00 |
14:30:10.76 |
-29:32:50.8 |
HIP 70941 |
15.32 |
| 2026-02-18 00:00 |
14:30:10.10 |
-29:32:53.9 |
HIP 70941 |
15.42 |
| 2026-02-18 12:00 |
14:30:09.42 |
-29:32:56.9 |
HIP 70941 |
15.52 |
| 2026-02-19 00:00 |
14:30:08.72 |
-29:32:59.7 |
HIP 70941 |
15.62 |
| 2026-02-19 12:00 |
14:30:08.00 |
-29:33:02.6 |
HIP 70941 |
15.73 |
| 2026-02-20 00:00 |
14:30:07.27 |
-29:33:05.3 |
HIP 70941 |
15.83 |
| 2026-02-20 12:00 |
14:30:06.52 |
-29:33:07.9 |
HIP 70941 |
15.94 |
| 2026-02-21 00:00 |
14:30:05.76 |
-29:33:10.4 |
HIP 70941 |
16.05 |
| 2026-02-21 12:00 |
14:30:04.98 |
-29:33:12.9 |
HIP 70941 |
16.15 |
| 2026-02-22 00:00 |
14:30:04.18 |
-29:33:15.2 |
HIP 70941 |
16.26 |
| 2026-02-22 12:00 |
14:30:03.37 |
-29:33:17.5 |
HIP 70941 |
16.37 |
| 2026-02-23 00:00 |
14:30:02.54 |
-29:33:19.7 |
HIP 70941 |
16.49 |
| 2026-02-23 12:00 |
14:30:01.70 |
-29:33:21.7 |
HIP 70941 |
16.60 |
| 2026-02-24 00:00 |
14:30:00.83 |
-29:33:23.7 |
HIP 70941 |
16.72 |