| Parameter |
Value |
| Designation |
C/1973 N1 (Sandage) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1973-11-08T03:45:29.695680Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:22Z |
| Obs used |
27 |
| NEO |
- |
| M1 |
6.200 |
| K1 |
10.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1974-02-27.0000000 |
| e |
1.00022570 |
| q (au) |
4.812051 |
| a (au) |
-21320.457837 |
| i (deg) |
137.403627 |
| Ω (om, deg) |
279.241065 |
| ω (w, deg) |
72.546350 |
| M (ma, deg) |
0.000035 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.938 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.938 |
| n |
6.000 |
| gf |
0.996 |
| gb |
-1.000 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
04:29:11.57 |
-05:49:44.1 |
HIP 20932 |
9.10 |
| 2026-05-12 12:00 |
04:29:13.00 |
-05:49:38.3 |
HIP 20932 |
8.94 |
| 2026-05-13 00:00 |
04:29:14.43 |
-05:49:32.6 |
HIP 20932 |
8.79 |
| 2026-05-13 12:00 |
04:29:15.86 |
-05:49:27.0 |
HIP 20932 |
8.66 |
| 2026-05-14 00:00 |
04:29:17.29 |
-05:49:21.5 |
HIP 20932 |
8.54 |
| 2026-05-14 12:00 |
04:29:18.74 |
-05:49:16.0 |
HIP 20932 |
8.44 |
| 2026-05-15 00:00 |
04:29:20.18 |
-05:49:10.6 |
HIP 20932 |
8.35 |
| 2026-05-15 12:00 |
04:29:21.63 |
-05:49:05.3 |
HIP 20932 |
8.28 |
| 2026-05-16 00:00 |
04:29:23.08 |
-05:49:00.1 |
HIP 20932 |
8.23 |
| 2026-05-16 12:00 |
04:29:24.53 |
-05:48:55.0 |
HIP 20932 |
8.20 |
| 2026-05-17 00:00 |
04:29:25.99 |
-05:48:49.9 |
HIP 20932 |
8.18 |
| 2026-05-17 12:00 |
04:29:27.45 |
-05:48:45.0 |
HIP 20932 |
8.18 |
| 2026-05-18 00:00 |
04:29:28.91 |
-05:48:40.1 |
HIP 20932 |
8.21 |
| 2026-05-18 12:00 |
04:29:30.37 |
-05:48:35.3 |
HIP 20932 |
8.25 |
| 2026-05-19 00:00 |
04:29:31.84 |
-05:48:30.6 |
HIP 20932 |
8.30 |
| 2026-05-19 12:00 |
04:29:33.31 |
-05:48:26.0 |
HIP 20932 |
8.38 |
| 2026-05-20 00:00 |
04:29:34.78 |
-05:48:21.4 |
HIP 20932 |
8.47 |
| 2026-05-20 12:00 |
04:29:36.26 |
-05:48:17.0 |
HIP 20932 |
8.58 |
| 2026-05-21 00:00 |
04:29:37.74 |
-05:48:12.6 |
HIP 20932 |
8.71 |
| 2026-05-21 12:00 |
04:29:39.22 |
-05:48:08.4 |
HIP 20932 |
8.85 |
| 2026-05-22 00:00 |
04:29:40.70 |
-05:48:04.2 |
HIP 20932 |
9.01 |
| 2026-05-22 12:00 |
04:29:42.18 |
-05:48:00.1 |
HIP 20932 |
9.18 |
| 2026-05-23 00:00 |
04:29:43.66 |
-05:47:56.1 |
HIP 20932 |
9.36 |
| 2026-05-23 12:00 |
04:29:45.15 |
-05:47:52.1 |
HIP 20932 |
9.56 |
| 2026-05-24 00:00 |
04:29:46.64 |
-05:47:48.3 |
HIP 20932 |
9.77 |
| 2026-05-24 12:00 |
04:29:48.13 |
-05:47:44.6 |
HIP 20932 |
9.99 |
| 2026-05-25 00:00 |
04:29:49.62 |
-05:47:40.9 |
HIP 20932 |
10.21 |
| 2026-05-25 12:00 |
04:29:51.11 |
-05:47:37.3 |
HIP 20932 |
10.45 |
| 2026-05-26 00:00 |
04:29:52.60 |
-05:47:33.9 |
HIP 20932 |
10.70 |
| 2026-05-26 12:00 |
04:29:54.09 |
-05:47:30.5 |
HIP 20932 |
10.96 |
| 2026-05-27 00:00 |
04:29:55.59 |
-05:47:27.2 |
HIP 20932 |
11.22 |
| 2026-05-27 12:00 |
04:29:57.08 |
-05:47:23.9 |
HIP 20932 |
11.50 |
| 2026-05-28 00:00 |
04:29:58.58 |
-05:47:20.8 |
HIP 20932 |
11.77 |
| 2026-05-28 12:00 |
04:30:00.07 |
-05:47:17.8 |
HIP 20932 |
12.06 |
| 2026-05-29 00:00 |
04:30:01.57 |
-05:47:14.9 |
HIP 20932 |
12.35 |
| 2026-05-29 12:00 |
04:30:03.07 |
-05:47:12.0 |
HIP 20932 |
12.64 |
| 2026-05-30 00:00 |
04:30:04.56 |
-05:47:09.2 |
HIP 20932 |
12.94 |
| 2026-05-30 12:00 |
04:30:06.06 |
-05:47:06.6 |
HIP 20932 |
13.25 |
| 2026-05-31 00:00 |
04:30:07.56 |
-05:47:04.0 |
HIP 20932 |
13.56 |
| 2026-05-31 12:00 |
04:30:09.06 |
-05:47:01.5 |
HIP 20932 |
13.87 |
| 2026-06-01 00:00 |
04:30:10.55 |
-05:46:59.1 |
HIP 20932 |
14.19 |
| 2026-06-01 12:00 |
04:30:12.05 |
-05:46:56.8 |
HIP 20932 |
14.51 |
| 2026-06-02 00:00 |
04:30:13.55 |
-05:46:54.6 |
HIP 20932 |
14.83 |