| Parameter |
Value |
| Designation |
C/1972 L1 (Sandage) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1972-11-14T18:55:18.753600Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:21Z |
| Obs used |
146 |
| NEO |
- |
| M1 |
5.600 |
| K1 |
7.250 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1972-10-11.0000000 |
| e |
1.00634381 |
| q (au) |
4.275741 |
| a (au) |
-674.001905 |
| i (deg) |
79.368060 |
| Ω (om, deg) |
225.486355 |
| ω (w, deg) |
56.654504 |
| M (ma, deg) |
-0.001960 |
Magnitude
Scatter + Global Linear
$$
M_a = (6.002 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
6.002 |
| n |
2.000 |
| gf |
0.993 |
| gb |
-1.000 |
| k |
1.000 |
| δ90 |
9.993 |
| 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 |
03:43:52.14 |
-08:59:39.5 |
HIP 17360 |
15.90 |
| 2026-05-12 12:00 |
03:43:53.65 |
-08:59:34.5 |
HIP 17360 |
16.18 |
| 2026-05-13 00:00 |
03:43:55.16 |
-08:59:29.5 |
HIP 17360 |
16.46 |
| 2026-05-13 12:00 |
03:43:56.68 |
-08:59:24.5 |
HIP 17360 |
16.75 |
| 2026-05-14 00:00 |
03:43:58.20 |
-08:59:19.7 |
HIP 17360 |
17.04 |
| 2026-05-14 12:00 |
03:43:59.72 |
-08:59:15.0 |
HIP 17360 |
17.34 |
| 2026-05-15 00:00 |
03:44:01.24 |
-08:59:10.4 |
HIP 17360 |
17.64 |
| 2026-05-15 12:00 |
03:44:02.76 |
-08:59:05.8 |
HIP 17360 |
17.94 |
| 2026-05-16 00:00 |
03:44:04.28 |
-08:59:01.4 |
HIP 17360 |
18.25 |
| 2026-05-16 12:00 |
03:44:05.80 |
-08:58:57.0 |
HIP 17360 |
18.56 |
| 2026-05-17 00:00 |
03:44:07.32 |
-08:58:52.7 |
HIP 17360 |
18.88 |
| 2026-05-17 12:00 |
03:44:08.85 |
-08:58:48.5 |
HIP 17360 |
19.20 |
| 2026-05-18 00:00 |
03:44:10.37 |
-08:58:44.4 |
HIP 17360 |
19.52 |
| 2026-05-18 12:00 |
03:44:11.89 |
-08:58:40.4 |
HIP 17360 |
19.84 |
| 2026-05-19 00:00 |
03:44:13.42 |
-08:58:36.5 |
HIP 17360 |
20.17 |
| 2026-05-19 12:00 |
03:44:14.94 |
-08:58:32.7 |
HIP 17360 |
20.50 |
| 2026-05-20 00:00 |
03:44:16.47 |
-08:58:29.0 |
HIP 17360 |
20.83 |
| 2026-05-20 12:00 |
03:44:17.99 |
-08:58:25.4 |
HIP 17360 |
21.16 |
| 2026-05-21 00:00 |
03:44:19.51 |
-08:58:21.8 |
HIP 17360 |
21.50 |
| 2026-05-21 12:00 |
03:44:21.04 |
-08:58:18.4 |
HIP 17360 |
21.84 |
| 2026-05-22 00:00 |
03:44:22.56 |
-08:58:15.1 |
HIP 17360 |
22.18 |
| 2026-05-22 12:00 |
03:44:24.08 |
-08:58:11.8 |
HIP 17360 |
22.52 |
| 2026-05-23 00:00 |
03:44:25.60 |
-08:58:08.6 |
HIP 17582 |
22.83 |
| 2026-05-23 12:00 |
03:44:27.12 |
-08:58:05.6 |
HIP 17582 |
22.46 |
| 2026-05-24 00:00 |
03:44:28.64 |
-08:58:02.6 |
HIP 17582 |
22.10 |
| 2026-05-24 12:00 |
03:44:30.16 |
-08:57:59.8 |
HIP 17582 |
21.73 |
| 2026-05-25 00:00 |
03:44:31.68 |
-08:57:57.0 |
HIP 17582 |
21.36 |
| 2026-05-25 12:00 |
03:44:33.20 |
-08:57:54.3 |
HIP 17582 |
21.00 |
| 2026-05-26 00:00 |
03:44:34.71 |
-08:57:51.7 |
HIP 17582 |
20.63 |
| 2026-05-26 12:00 |
03:44:36.23 |
-08:57:49.2 |
HIP 17582 |
20.27 |
| 2026-05-27 00:00 |
03:44:37.74 |
-08:57:46.8 |
HIP 17582 |
19.90 |
| 2026-05-27 12:00 |
03:44:39.25 |
-08:57:44.5 |
HIP 17582 |
19.54 |
| 2026-05-28 00:00 |
03:44:40.76 |
-08:57:42.3 |
HIP 17582 |
19.17 |
| 2026-05-28 12:00 |
03:44:42.27 |
-08:57:40.2 |
HIP 17582 |
18.81 |
| 2026-05-29 00:00 |
03:44:43.77 |
-08:57:38.2 |
HIP 17582 |
18.45 |
| 2026-05-29 12:00 |
03:44:45.27 |
-08:57:36.3 |
HIP 17582 |
18.09 |
| 2026-05-30 00:00 |
03:44:46.78 |
-08:57:34.5 |
HIP 17582 |
17.73 |
| 2026-05-30 12:00 |
03:44:48.28 |
-08:57:32.8 |
HIP 17582 |
17.37 |
| 2026-05-31 00:00 |
03:44:49.77 |
-08:57:31.1 |
HIP 17582 |
17.01 |
| 2026-05-31 12:00 |
03:44:51.27 |
-08:57:29.6 |
HIP 17582 |
16.65 |
| 2026-06-01 00:00 |
03:44:52.76 |
-08:57:28.2 |
HIP 17582 |
16.29 |
| 2026-06-01 12:00 |
03:44:54.25 |
-08:57:26.9 |
HIP 17582 |
15.93 |
| 2026-06-02 00:00 |
03:44:55.74 |
-08:57:25.6 |
HIP 17582 |
15.58 |