| 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) |
| 2026-06-01 00:00 |
00:51:42.13 |
+29:16:43.6 |
HIP 4132 |
19.89 |
| 2026-06-01 12:00 |
00:51:42.99 |
+29:16:55.0 |
HIP 4132 |
19.86 |
| 2026-06-02 00:00 |
00:51:43.83 |
+29:17:06.3 |
HIP 4132 |
19.84 |
| 2026-06-02 12:00 |
00:51:44.67 |
+29:17:17.7 |
HIP 4132 |
19.82 |
| 2026-06-03 00:00 |
00:51:45.50 |
+29:17:29.0 |
HIP 4132 |
19.80 |
| 2026-06-03 12:00 |
00:51:46.31 |
+29:17:40.3 |
HIP 4132 |
19.79 |
| 2026-06-04 00:00 |
00:51:47.12 |
+29:17:51.6 |
HIP 4132 |
19.79 |
| 2026-06-04 12:00 |
00:51:47.91 |
+29:18:02.9 |
HIP 4132 |
19.79 |
| 2026-06-05 00:00 |
00:51:48.69 |
+29:18:14.2 |
HIP 4132 |
19.79 |
| 2026-06-05 12:00 |
00:51:49.46 |
+29:18:25.4 |
HIP 4132 |
19.80 |
| 2026-06-06 00:00 |
00:51:50.22 |
+29:18:36.6 |
HIP 4132 |
19.82 |
| 2026-06-06 12:00 |
00:51:50.97 |
+29:18:47.8 |
HIP 4132 |
19.84 |
| 2026-06-07 00:00 |
00:51:51.70 |
+29:18:59.0 |
HIP 4132 |
19.86 |
| 2026-06-07 12:00 |
00:51:52.43 |
+29:19:10.2 |
HIP 4132 |
19.89 |
| 2026-06-08 00:00 |
00:51:53.14 |
+29:19:21.3 |
HIP 4132 |
19.92 |
| 2026-06-08 12:00 |
00:51:53.84 |
+29:19:32.4 |
HIP 4132 |
19.96 |
| 2026-06-09 00:00 |
00:51:54.53 |
+29:19:43.5 |
HIP 4132 |
20.00 |
| 2026-06-09 12:00 |
00:51:55.21 |
+29:19:54.6 |
HIP 4132 |
20.05 |
| 2026-06-10 00:00 |
00:51:55.87 |
+29:20:05.6 |
HIP 4132 |
20.10 |
| 2026-06-10 12:00 |
00:51:56.52 |
+29:20:16.6 |
HIP 4132 |
20.15 |
| 2026-06-11 00:00 |
00:51:57.16 |
+29:20:27.6 |
HIP 4132 |
20.21 |
| 2026-06-11 12:00 |
00:51:57.79 |
+29:20:38.6 |
HIP 4132 |
20.27 |
| 2026-06-12 00:00 |
00:51:58.41 |
+29:20:49.5 |
HIP 4132 |
20.33 |
| 2026-06-12 12:00 |
00:51:59.01 |
+29:21:00.4 |
HIP 4132 |
20.40 |
| 2026-06-13 00:00 |
00:51:59.61 |
+29:21:11.3 |
HIP 4132 |
20.47 |
| 2026-06-13 12:00 |
00:52:00.19 |
+29:21:22.1 |
HIP 4132 |
20.55 |
| 2026-06-14 00:00 |
00:52:00.75 |
+29:21:32.9 |
HIP 4132 |
20.63 |
| 2026-06-14 12:00 |
00:52:01.31 |
+29:21:43.7 |
HIP 4132 |
20.71 |
| 2026-06-15 00:00 |
00:52:01.85 |
+29:21:54.4 |
HIP 4132 |
20.79 |
| 2026-06-15 12:00 |
00:52:02.38 |
+29:22:05.1 |
HIP 4132 |
20.88 |
| 2026-06-16 00:00 |
00:52:02.90 |
+29:22:15.8 |
HIP 4132 |
20.97 |
| 2026-06-16 12:00 |
00:52:03.40 |
+29:22:26.4 |
HIP 4132 |
21.06 |
| 2026-06-17 00:00 |
00:52:03.89 |
+29:22:37.0 |
HIP 4132 |
21.15 |
| 2026-06-17 12:00 |
00:52:04.37 |
+29:22:47.5 |
HIP 4197 |
21.21 |
| 2026-06-18 00:00 |
00:52:04.84 |
+29:22:58.1 |
HIP 4197 |
21.06 |
| 2026-06-18 12:00 |
00:52:05.29 |
+29:23:08.5 |
HIP 4197 |
20.91 |
| 2026-06-19 00:00 |
00:52:05.74 |
+29:23:19.0 |
HIP 4197 |
20.77 |
| 2026-06-19 12:00 |
00:52:06.16 |
+29:23:29.4 |
HIP 4197 |
20.63 |
| 2026-06-20 00:00 |
00:52:06.58 |
+29:23:39.7 |
HIP 4197 |
20.49 |
| 2026-06-20 12:00 |
00:52:06.98 |
+29:23:50.0 |
HIP 4197 |
20.36 |
| 2026-06-21 00:00 |
00:52:07.37 |
+29:24:00.3 |
HIP 4197 |
20.23 |
| 2026-06-21 12:00 |
00:52:07.75 |
+29:24:10.5 |
HIP 4197 |
20.11 |
| 2026-06-22 00:00 |
00:52:08.11 |
+29:24:20.7 |
HIP 4197 |
19.99 |