| 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) |
| 2026-03-26 00:00 |
14:28:43.08 |
-29:32:30.4 |
HIP 70753 |
7.71 |
| 2026-03-26 12:00 |
14:28:41.42 |
-29:32:26.7 |
HIP 70753 |
7.36 |
| 2026-03-27 00:00 |
14:28:39.74 |
-29:32:22.8 |
HIP 70753 |
7.00 |
| 2026-03-27 12:00 |
14:28:38.05 |
-29:32:18.8 |
HIP 70753 |
6.63 |
| 2026-03-28 00:00 |
14:28:36.35 |
-29:32:14.8 |
HIP 70753 |
6.27 |
| 2026-03-28 12:00 |
14:28:34.65 |
-29:32:10.6 |
HIP 70753 |
5.91 |
| 2026-03-29 00:00 |
14:28:32.93 |
-29:32:06.4 |
HIP 70753 |
5.55 |
| 2026-03-29 12:00 |
14:28:31.21 |
-29:32:02.0 |
HIP 70753 |
5.18 |
| 2026-03-30 00:00 |
14:28:29.47 |
-29:31:57.6 |
HIP 70753 |
4.82 |
| 2026-03-30 12:00 |
14:28:27.73 |
-29:31:53.1 |
HIP 70753 |
4.46 |
| 2026-03-31 00:00 |
14:28:25.98 |
-29:31:48.5 |
HIP 70753 |
4.10 |
| 2026-03-31 12:00 |
14:28:24.22 |
-29:31:43.8 |
HIP 70753 |
3.74 |
| 2026-04-01 00:00 |
14:28:22.45 |
-29:31:39.0 |
HIP 70753 |
3.39 |
| 2026-04-01 12:00 |
14:28:20.67 |
-29:31:34.2 |
HIP 70753 |
3.04 |
| 2026-04-02 00:00 |
14:28:18.89 |
-29:31:29.2 |
HIP 70753 |
2.71 |
| 2026-04-02 12:00 |
14:28:17.10 |
-29:31:24.2 |
HIP 70753 |
2.39 |
| 2026-04-03 00:00 |
14:28:15.30 |
-29:31:19.0 |
HIP 70753 |
2.11 |
| 2026-04-03 12:00 |
14:28:13.49 |
-29:31:13.8 |
HIP 70753 |
1.86 |
| 2026-04-04 00:00 |
14:28:11.67 |
-29:31:08.5 |
HIP 70753 |
1.67 |
| 2026-04-04 12:00 |
14:28:09.85 |
-29:31:03.1 |
HIP 70753 |
1.56 |
| 2026-04-05 00:00 |
14:28:08.02 |
-29:30:57.6 |
HIP 70753 |
1.56 |
| 2026-04-05 12:00 |
14:28:06.18 |
-29:30:52.0 |
HIP 70753 |
1.66 |
| 2026-04-06 00:00 |
14:28:04.34 |
-29:30:46.4 |
HIP 70753 |
1.84 |
| 2026-04-06 12:00 |
14:28:02.49 |
-29:30:40.6 |
HIP 70753 |
2.10 |
| 2026-04-07 00:00 |
14:28:00.63 |
-29:30:34.8 |
HIP 70753 |
2.40 |
| 2026-04-07 12:00 |
14:27:58.76 |
-29:30:28.9 |
HIP 70753 |
2.73 |
| 2026-04-08 00:00 |
14:27:56.89 |
-29:30:22.9 |
HIP 70753 |
3.08 |
| 2026-04-08 12:00 |
14:27:55.01 |
-29:30:16.8 |
HIP 70753 |
3.45 |
| 2026-04-09 00:00 |
14:27:53.13 |
-29:30:10.6 |
HIP 70753 |
3.83 |
| 2026-04-09 12:00 |
14:27:51.24 |
-29:30:04.3 |
HIP 70753 |
4.22 |
| 2026-04-10 00:00 |
14:27:49.34 |
-29:29:58.0 |
HIP 70753 |
4.62 |
| 2026-04-10 12:00 |
14:27:47.44 |
-29:29:51.6 |
HIP 70753 |
5.02 |
| 2026-04-11 00:00 |
14:27:45.53 |
-29:29:45.1 |
HIP 70753 |
5.43 |
| 2026-04-11 12:00 |
14:27:43.62 |
-29:29:38.5 |
HIP 70753 |
5.84 |
| 2026-04-12 00:00 |
14:27:41.70 |
-29:29:31.8 |
HIP 70753 |
6.26 |
| 2026-04-12 12:00 |
14:27:39.77 |
-29:29:25.0 |
HIP 70753 |
6.67 |
| 2026-04-13 00:00 |
14:27:37.84 |
-29:29:18.2 |
HIP 70753 |
7.10 |
| 2026-04-13 12:00 |
14:27:35.91 |
-29:29:11.3 |
HIP 70753 |
7.52 |
| 2026-04-14 00:00 |
14:27:33.97 |
-29:29:04.3 |
HIP 70753 |
7.95 |
| 2026-04-14 12:00 |
14:27:32.03 |
-29:28:57.2 |
HIP 70753 |
8.38 |
| 2026-04-15 00:00 |
14:27:30.08 |
-29:28:50.1 |
HIP 70753 |
8.81 |
| 2026-04-15 12:00 |
14:27:28.12 |
-29:28:42.8 |
HIP 70753 |
9.24 |
| 2026-04-16 00:00 |
14:27:26.17 |
-29:28:35.5 |
HIP 70753 |
9.68 |