| 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) |
| 2026-05-12 00:00 |
11:56:21.61 |
-01:31:04.2 |
HIP 58191 |
6.82 |
| 2026-05-12 12:00 |
11:56:20.56 |
-01:30:56.7 |
HIP 58191 |
6.54 |
| 2026-05-13 00:00 |
11:56:19.53 |
-01:30:49.2 |
HIP 58191 |
6.27 |
| 2026-05-13 12:00 |
11:56:18.51 |
-01:30:41.8 |
HIP 58191 |
6.00 |
| 2026-05-14 00:00 |
11:56:17.50 |
-01:30:34.4 |
HIP 58191 |
5.73 |
| 2026-05-14 12:00 |
11:56:16.50 |
-01:30:27.1 |
HIP 58191 |
5.47 |
| 2026-05-15 00:00 |
11:56:15.51 |
-01:30:19.9 |
HIP 58191 |
5.21 |
| 2026-05-15 12:00 |
11:56:14.53 |
-01:30:12.8 |
HIP 58191 |
4.96 |
| 2026-05-16 00:00 |
11:56:13.57 |
-01:30:05.7 |
HIP 58191 |
4.71 |
| 2026-05-16 12:00 |
11:56:12.62 |
-01:29:58.7 |
HIP 58191 |
4.47 |
| 2026-05-17 00:00 |
11:56:11.67 |
-01:29:51.8 |
HIP 58191 |
4.23 |
| 2026-05-17 12:00 |
11:56:10.75 |
-01:29:44.9 |
HIP 58191 |
4.00 |
| 2026-05-18 00:00 |
11:56:09.83 |
-01:29:38.2 |
HIP 58191 |
3.77 |
| 2026-05-18 12:00 |
11:56:08.92 |
-01:29:31.4 |
HIP 58191 |
3.56 |
| 2026-05-19 00:00 |
11:56:08.03 |
-01:29:24.8 |
HIP 58191 |
3.35 |
| 2026-05-19 12:00 |
11:56:07.15 |
-01:29:18.2 |
HIP 58191 |
3.14 |
| 2026-05-20 00:00 |
11:56:06.28 |
-01:29:11.8 |
HIP 58191 |
2.95 |
| 2026-05-20 12:00 |
11:56:05.42 |
-01:29:05.4 |
HIP 58191 |
2.76 |
| 2026-05-21 00:00 |
11:56:04.57 |
-01:28:59.0 |
HIP 58191 |
2.59 |
| 2026-05-21 12:00 |
11:56:03.74 |
-01:28:52.8 |
HIP 58191 |
2.43 |
| 2026-05-22 00:00 |
11:56:02.92 |
-01:28:46.6 |
HIP 58191 |
2.29 |
| 2026-05-22 12:00 |
11:56:02.11 |
-01:28:40.5 |
HIP 58191 |
2.16 |
| 2026-05-23 00:00 |
11:56:01.31 |
-01:28:34.5 |
HIP 58191 |
2.05 |
| 2026-05-23 12:00 |
11:56:00.53 |
-01:28:28.5 |
HIP 58191 |
1.96 |
| 2026-05-24 00:00 |
11:55:59.76 |
-01:28:22.6 |
HIP 58191 |
1.89 |
| 2026-05-24 12:00 |
11:55:59.00 |
-01:28:16.8 |
HIP 58191 |
1.84 |
| 2026-05-25 00:00 |
11:55:58.25 |
-01:28:11.1 |
HIP 58191 |
1.82 |
| 2026-05-25 12:00 |
11:55:57.52 |
-01:28:05.5 |
HIP 58191 |
1.82 |
| 2026-05-26 00:00 |
11:55:56.80 |
-01:28:00.0 |
HIP 58191 |
1.85 |
| 2026-05-26 12:00 |
11:55:56.09 |
-01:27:54.4 |
HIP 58191 |
1.89 |
| 2026-05-27 00:00 |
11:55:55.39 |
-01:27:49.0 |
HIP 58191 |
1.95 |
| 2026-05-27 12:00 |
11:55:54.71 |
-01:27:43.7 |
HIP 58191 |
2.03 |
| 2026-05-28 00:00 |
11:55:54.04 |
-01:27:38.5 |
HIP 58191 |
2.12 |
| 2026-05-28 12:00 |
11:55:53.38 |
-01:27:33.3 |
HIP 58191 |
2.22 |
| 2026-05-29 00:00 |
11:55:52.73 |
-01:27:28.2 |
HIP 58191 |
2.33 |
| 2026-05-29 12:00 |
11:55:52.10 |
-01:27:23.2 |
HIP 58191 |
2.44 |
| 2026-05-30 00:00 |
11:55:51.48 |
-01:27:18.3 |
HIP 58191 |
2.56 |
| 2026-05-30 12:00 |
11:55:50.87 |
-01:27:13.5 |
HIP 58191 |
2.69 |
| 2026-05-31 00:00 |
11:55:50.28 |
-01:27:08.7 |
HIP 58191 |
2.81 |
| 2026-05-31 12:00 |
11:55:49.70 |
-01:27:04.0 |
HIP 58191 |
2.94 |
| 2026-06-01 00:00 |
11:55:49.13 |
-01:26:59.4 |
HIP 58191 |
3.07 |
| 2026-06-01 12:00 |
11:55:48.57 |
-01:26:54.9 |
HIP 58191 |
3.19 |
| 2026-06-02 00:00 |
11:55:48.03 |
-01:26:50.5 |
HIP 58191 |
3.32 |