| Parameter |
Value |
| Designation |
C/1974 O1 (Cesco) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1974-05-12T23:37:48.135360Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:22Z |
| Obs used |
18 |
| NEO |
- |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1974-08-21.0000000 |
| e |
0.97938205 |
| q (au) |
1.372893 |
| a (au) |
66.587290 |
| i (deg) |
173.158463 |
| Ω (om, deg) |
165.740646 |
| ω (w, deg) |
176.764065 |
| M (ma, deg) |
0.181420 |
Magnitude
Scatter + Global Linear
$$
M_a = (H_0 + n\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
- |
| n |
- |
| gf |
- |
| gb |
- |
| k |
- |
| δ90 |
- |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
11:58:31.91 |
-01:42:05.0 |
HIP 58480 |
20.26 |
| 2026-09-20 12:00 |
11:58:33.46 |
-01:42:14.9 |
HIP 58480 |
19.86 |
| 2026-09-21 00:00 |
11:58:35.00 |
-01:42:24.9 |
HIP 58480 |
19.46 |
| 2026-09-21 12:00 |
11:58:36.55 |
-01:42:34.8 |
HIP 58480 |
19.06 |
| 2026-09-22 00:00 |
11:58:38.09 |
-01:42:44.8 |
HIP 58480 |
18.66 |
| 2026-09-22 12:00 |
11:58:39.64 |
-01:42:54.7 |
HIP 58480 |
18.26 |
| 2026-09-23 00:00 |
11:58:41.18 |
-01:43:04.7 |
HIP 58480 |
17.86 |
| 2026-09-23 12:00 |
11:58:42.73 |
-01:43:14.7 |
HIP 58480 |
17.46 |
| 2026-09-24 00:00 |
11:58:44.27 |
-01:43:24.6 |
HIP 58480 |
17.07 |
| 2026-09-24 12:00 |
11:58:45.81 |
-01:43:34.6 |
HIP 58480 |
16.67 |
| 2026-09-25 00:00 |
11:58:47.36 |
-01:43:44.6 |
HIP 58480 |
16.28 |
| 2026-09-25 12:00 |
11:58:48.90 |
-01:43:54.6 |
HIP 58480 |
15.89 |
| 2026-09-26 00:00 |
11:58:50.45 |
-01:44:04.6 |
HIP 58480 |
15.50 |
| 2026-09-26 12:00 |
11:58:51.99 |
-01:44:14.6 |
HIP 58480 |
15.11 |
| 2026-09-27 00:00 |
11:58:53.53 |
-01:44:24.6 |
HIP 58480 |
14.72 |
| 2026-09-27 12:00 |
11:58:55.07 |
-01:44:34.6 |
HIP 58480 |
14.34 |
| 2026-09-28 00:00 |
11:58:56.61 |
-01:44:44.6 |
HIP 58480 |
13.96 |
| 2026-09-28 12:00 |
11:58:58.15 |
-01:44:54.6 |
HIP 58480 |
13.58 |
| 2026-09-29 00:00 |
11:58:59.68 |
-01:45:04.6 |
HIP 58480 |
13.20 |
| 2026-09-29 12:00 |
11:59:01.22 |
-01:45:14.6 |
HIP 58480 |
12.83 |
| 2026-09-30 00:00 |
11:59:02.75 |
-01:45:24.6 |
HIP 58480 |
12.45 |
| 2026-09-30 12:00 |
11:59:04.29 |
-01:45:34.6 |
HIP 58480 |
12.09 |
| 2026-10-01 00:00 |
11:59:05.82 |
-01:45:44.6 |
HIP 58480 |
11.72 |
| 2026-10-01 12:00 |
11:59:07.35 |
-01:45:54.6 |
HIP 58480 |
11.36 |
| 2026-10-02 00:00 |
11:59:08.87 |
-01:46:04.5 |
HIP 58480 |
11.00 |
| 2026-10-02 12:00 |
11:59:10.40 |
-01:46:14.5 |
HIP 58480 |
10.65 |
| 2026-10-03 00:00 |
11:59:11.92 |
-01:46:24.5 |
HIP 58480 |
10.31 |
| 2026-10-03 12:00 |
11:59:13.44 |
-01:46:34.4 |
HIP 58480 |
9.96 |
| 2026-10-04 00:00 |
11:59:14.96 |
-01:46:44.4 |
HIP 58480 |
9.63 |
| 2026-10-04 12:00 |
11:59:16.48 |
-01:46:54.3 |
HIP 58480 |
9.30 |
| 2026-10-05 00:00 |
11:59:17.99 |
-01:47:04.3 |
HIP 58480 |
8.98 |
| 2026-10-05 12:00 |
11:59:19.51 |
-01:47:14.2 |
HIP 58480 |
8.67 |
| 2026-10-06 00:00 |
11:59:21.01 |
-01:47:24.1 |
HIP 58480 |
8.37 |
| 2026-10-06 12:00 |
11:59:22.52 |
-01:47:34.0 |
HIP 58480 |
8.07 |
| 2026-10-07 00:00 |
11:59:24.02 |
-01:47:43.9 |
HIP 58480 |
7.79 |
| 2026-10-07 12:00 |
11:59:25.52 |
-01:47:53.8 |
HIP 58480 |
7.52 |
| 2026-10-08 00:00 |
11:59:27.02 |
-01:48:03.7 |
HIP 58480 |
7.26 |
| 2026-10-08 12:00 |
11:59:28.51 |
-01:48:13.5 |
HIP 58480 |
7.02 |
| 2026-10-09 00:00 |
11:59:30.00 |
-01:48:23.3 |
HIP 58480 |
6.80 |
| 2026-10-09 12:00 |
11:59:31.49 |
-01:48:33.1 |
HIP 58480 |
6.59 |
| 2026-10-10 00:00 |
11:59:32.97 |
-01:48:42.9 |
HIP 58480 |
6.40 |
| 2026-10-10 12:00 |
11:59:34.45 |
-01:48:52.7 |
HIP 58480 |
6.24 |
| 2026-10-11 00:00 |
11:59:35.92 |
-01:49:02.5 |
HIP 58480 |
6.09 |