| Parameter |
Value |
| Designation |
C/1973 A1 (Heck-Sause) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1972-10-05T11:17:13.539840Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:22Z |
| Obs used |
190 |
| NEO |
- |
| M1 |
5.500 |
| K1 |
10.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1973-03-02.0000000 |
| e |
1.00057319 |
| q (au) |
2.511110 |
| a (au) |
-4380.958906 |
| i (deg) |
138.630150 |
| Ω (om, deg) |
175.878043 |
| ω (w, deg) |
346.237180 |
| M (ma, deg) |
0.000501 |
Magnitude
Scatter + Global Linear
$$
M_a = (2.285 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
2.285 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| k |
1.000 |
| 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) |
| 2026-03-26 00:00 |
00:48:40.43 |
+28:54:48.8 |
HIP 3830 |
13.30 |
| 2026-03-26 12:00 |
00:48:41.98 |
+28:54:54.9 |
HIP 3830 |
13.23 |
| 2026-03-27 00:00 |
00:48:43.54 |
+28:55:01.0 |
HIP 3830 |
13.17 |
| 2026-03-27 12:00 |
00:48:45.10 |
+28:55:07.2 |
HIP 3830 |
13.12 |
| 2026-03-28 00:00 |
00:48:46.66 |
+28:55:13.5 |
HIP 3830 |
13.08 |
| 2026-03-28 12:00 |
00:48:48.22 |
+28:55:19.9 |
HIP 3830 |
13.05 |
| 2026-03-29 00:00 |
00:48:49.79 |
+28:55:26.4 |
HIP 3830 |
13.03 |
| 2026-03-29 12:00 |
00:48:51.35 |
+28:55:32.9 |
HIP 3830 |
13.02 |
| 2026-03-30 00:00 |
00:48:52.92 |
+28:55:39.5 |
HIP 3830 |
13.03 |
| 2026-03-30 12:00 |
00:48:54.48 |
+28:55:46.2 |
HIP 3830 |
13.04 |
| 2026-03-31 00:00 |
00:48:56.05 |
+28:55:53.0 |
HIP 3830 |
13.07 |
| 2026-03-31 12:00 |
00:48:57.62 |
+28:56:00.0 |
HIP 3830 |
13.11 |
| 2026-04-01 00:00 |
00:48:59.18 |
+28:56:06.9 |
HIP 3830 |
13.16 |
| 2026-04-01 12:00 |
00:49:00.75 |
+28:56:13.9 |
HIP 3830 |
13.22 |
| 2026-04-02 00:00 |
00:49:02.32 |
+28:56:21.0 |
HIP 3830 |
13.29 |
| 2026-04-02 12:00 |
00:49:03.89 |
+28:56:28.2 |
HIP 3830 |
13.37 |
| 2026-04-03 00:00 |
00:49:05.46 |
+28:56:35.5 |
HIP 3830 |
13.46 |
| 2026-04-03 12:00 |
00:49:07.03 |
+28:56:42.8 |
HIP 3830 |
13.57 |
| 2026-04-04 00:00 |
00:49:08.60 |
+28:56:50.2 |
HIP 3830 |
13.68 |
| 2026-04-04 12:00 |
00:49:10.17 |
+28:56:57.7 |
HIP 3830 |
13.80 |
| 2026-04-05 00:00 |
00:49:11.74 |
+28:57:05.3 |
HIP 3830 |
13.94 |
| 2026-04-05 12:00 |
00:49:13.31 |
+28:57:12.9 |
HIP 3830 |
14.08 |
| 2026-04-06 00:00 |
00:49:14.88 |
+28:57:20.7 |
HIP 3830 |
14.23 |
| 2026-04-06 12:00 |
00:49:16.44 |
+28:57:28.5 |
HIP 3830 |
14.39 |
| 2026-04-07 00:00 |
00:49:18.01 |
+28:57:36.3 |
HIP 3830 |
14.56 |
| 2026-04-07 12:00 |
00:49:19.58 |
+28:57:44.3 |
HIP 3830 |
14.74 |
| 2026-04-08 00:00 |
00:49:21.14 |
+28:57:52.3 |
HIP 3830 |
14.93 |
| 2026-04-08 12:00 |
00:49:22.71 |
+28:58:00.4 |
HIP 3830 |
15.12 |
| 2026-04-09 00:00 |
00:49:24.27 |
+28:58:08.5 |
HIP 3830 |
15.32 |
| 2026-04-09 12:00 |
00:49:25.83 |
+28:58:16.7 |
HIP 3830 |
15.53 |
| 2026-04-10 00:00 |
00:49:27.39 |
+28:58:25.0 |
HIP 3830 |
15.74 |
| 2026-04-10 12:00 |
00:49:28.95 |
+28:58:33.4 |
HIP 3830 |
15.97 |
| 2026-04-11 00:00 |
00:49:30.51 |
+28:58:41.8 |
HIP 3830 |
16.19 |
| 2026-04-11 12:00 |
00:49:32.07 |
+28:58:50.3 |
HIP 3830 |
16.43 |
| 2026-04-12 00:00 |
00:49:33.62 |
+28:58:58.9 |
HIP 3830 |
16.67 |
| 2026-04-12 12:00 |
00:49:35.17 |
+28:59:07.5 |
HIP 3830 |
16.91 |
| 2026-04-13 00:00 |
00:49:36.72 |
+28:59:16.2 |
HIP 3830 |
17.17 |
| 2026-04-13 12:00 |
00:49:38.27 |
+28:59:25.0 |
HIP 3830 |
17.42 |
| 2026-04-14 00:00 |
00:49:39.82 |
+28:59:33.8 |
HIP 3830 |
17.68 |
| 2026-04-14 12:00 |
00:49:41.36 |
+28:59:42.7 |
HIP 3830 |
17.95 |
| 2026-04-15 00:00 |
00:49:42.90 |
+28:59:51.7 |
HIP 3830 |
18.22 |
| 2026-04-15 12:00 |
00:49:44.44 |
+29:00:00.7 |
HIP 3830 |
18.49 |
| 2026-04-16 00:00 |
00:49:45.98 |
+29:00:09.7 |
HIP 3830 |
18.77 |