| 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 |
1988-03-23 |
-2.5184 |
+1.838 |
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 |
14:25:42.46 |
-29:20:42.0 |
HIP 70511 |
16.87 |
| 2026-05-12 12:00 |
14:25:40.50 |
-29:20:31.4 |
HIP 70511 |
16.61 |
| 2026-05-13 00:00 |
14:25:38.54 |
-29:20:20.8 |
HIP 70511 |
16.36 |
| 2026-05-13 12:00 |
14:25:36.59 |
-29:20:10.1 |
HIP 70511 |
16.11 |
| 2026-05-14 00:00 |
14:25:34.64 |
-29:19:59.4 |
HIP 70511 |
15.88 |
| 2026-05-14 12:00 |
14:25:32.69 |
-29:19:48.6 |
HIP 70511 |
15.65 |
| 2026-05-15 00:00 |
14:25:30.75 |
-29:19:37.8 |
HIP 70511 |
15.44 |
| 2026-05-15 12:00 |
14:25:28.82 |
-29:19:27.0 |
HIP 70511 |
15.23 |
| 2026-05-16 00:00 |
14:25:26.89 |
-29:19:16.1 |
HIP 70511 |
15.03 |
| 2026-05-16 12:00 |
14:25:24.96 |
-29:19:05.2 |
HIP 70511 |
14.85 |
| 2026-05-17 00:00 |
14:25:23.04 |
-29:18:54.2 |
HIP 70511 |
14.68 |
| 2026-05-17 12:00 |
14:25:21.12 |
-29:18:43.2 |
HIP 70511 |
14.52 |
| 2026-05-18 00:00 |
14:25:19.21 |
-29:18:32.2 |
HIP 70511 |
14.37 |
| 2026-05-18 12:00 |
14:25:17.31 |
-29:18:21.1 |
HIP 70511 |
14.23 |
| 2026-05-19 00:00 |
14:25:15.41 |
-29:18:10.0 |
HIP 70511 |
14.11 |
| 2026-05-19 12:00 |
14:25:13.51 |
-29:17:58.9 |
HIP 70511 |
13.99 |
| 2026-05-20 00:00 |
14:25:11.63 |
-29:17:47.7 |
HIP 70511 |
13.90 |
| 2026-05-20 12:00 |
14:25:09.74 |
-29:17:36.5 |
HIP 70511 |
13.81 |
| 2026-05-21 00:00 |
14:25:07.87 |
-29:17:25.3 |
HIP 70511 |
13.74 |
| 2026-05-21 12:00 |
14:25:06.00 |
-29:17:14.1 |
HIP 70511 |
13.68 |
| 2026-05-22 00:00 |
14:25:04.14 |
-29:17:02.8 |
HIP 70511 |
13.64 |
| 2026-05-22 12:00 |
14:25:02.28 |
-29:16:51.5 |
HIP 70511 |
13.60 |
| 2026-05-23 00:00 |
14:25:00.43 |
-29:16:40.1 |
HIP 70511 |
13.59 |
| 2026-05-23 12:00 |
14:24:58.59 |
-29:16:28.7 |
HIP 70511 |
13.58 |
| 2026-05-24 00:00 |
14:24:56.75 |
-29:16:17.4 |
HIP 70511 |
13.59 |
| 2026-05-24 12:00 |
14:24:54.93 |
-29:16:05.9 |
HIP 70511 |
13.62 |
| 2026-05-25 00:00 |
14:24:53.11 |
-29:15:54.5 |
HIP 70511 |
13.65 |
| 2026-05-25 12:00 |
14:24:51.29 |
-29:15:43.0 |
HIP 70511 |
13.70 |
| 2026-05-26 00:00 |
14:24:49.49 |
-29:15:31.5 |
HIP 70511 |
13.76 |
| 2026-05-26 12:00 |
14:24:47.69 |
-29:15:20.0 |
HIP 70511 |
13.84 |
| 2026-05-27 00:00 |
14:24:45.90 |
-29:15:08.5 |
HIP 70511 |
13.92 |
| 2026-05-27 12:00 |
14:24:44.11 |
-29:14:57.0 |
HIP 70511 |
14.02 |
| 2026-05-28 00:00 |
14:24:42.34 |
-29:14:45.4 |
HIP 70511 |
14.13 |
| 2026-05-28 12:00 |
14:24:40.57 |
-29:14:33.8 |
HIP 70511 |
14.25 |
| 2026-05-29 00:00 |
14:24:38.82 |
-29:14:22.2 |
HIP 70511 |
14.38 |
| 2026-05-29 12:00 |
14:24:37.07 |
-29:14:10.6 |
HIP 70511 |
14.52 |
| 2026-05-30 00:00 |
14:24:35.32 |
-29:13:58.9 |
HIP 70511 |
14.67 |
| 2026-05-30 12:00 |
14:24:33.59 |
-29:13:47.3 |
HIP 70511 |
14.83 |
| 2026-05-31 00:00 |
14:24:31.87 |
-29:13:35.6 |
HIP 70511 |
15.00 |
| 2026-05-31 12:00 |
14:24:30.15 |
-29:13:23.9 |
HIP 70511 |
15.18 |
| 2026-06-01 00:00 |
14:24:28.44 |
-29:13:12.2 |
HIP 70511 |
15.36 |
| 2026-06-01 12:00 |
14:24:26.75 |
-29:13:00.5 |
HIP 70511 |
15.55 |
| 2026-06-02 00:00 |
14:24:25.06 |
-29:12:48.8 |
HIP 70511 |
15.75 |