| Parameter |
Value |
| Designation |
C/1992 A1 (Helin-Alu) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1992-07-08T17:12:35.945280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:41Z |
| Obs used |
53 |
| NEO |
- |
| M1 |
12.200 |
| K1 |
4.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1992-02-26.0000000 |
| e |
1.00425169 |
| q (au) |
3.016597 |
| a (au) |
-709.504993 |
| i (deg) |
39.271080 |
| Ω (om, deg) |
288.912404 |
| ω (w, deg) |
239.843091 |
| M (ma, deg) |
-0.006974 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.138 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.138 |
| 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) |
| 2026-05-12 00:00 |
20:52:01.63 |
+03:20:34.6 |
HIP 102929 |
15.13 |
| 2026-05-12 12:00 |
20:52:01.34 |
+03:20:45.4 |
HIP 102929 |
14.97 |
| 2026-05-13 00:00 |
20:52:01.03 |
+03:20:56.0 |
HIP 102929 |
14.80 |
| 2026-05-13 12:00 |
20:52:00.70 |
+03:21:06.6 |
HIP 102929 |
14.63 |
| 2026-05-14 00:00 |
20:52:00.36 |
+03:21:17.1 |
HIP 102929 |
14.46 |
| 2026-05-14 12:00 |
20:52:00.00 |
+03:21:27.5 |
HIP 102929 |
14.29 |
| 2026-05-15 00:00 |
20:51:59.62 |
+03:21:37.8 |
HIP 102929 |
14.12 |
| 2026-05-15 12:00 |
20:51:59.22 |
+03:21:48.1 |
HIP 102929 |
13.94 |
| 2026-05-16 00:00 |
20:51:58.81 |
+03:21:58.2 |
HIP 102929 |
13.76 |
| 2026-05-16 12:00 |
20:51:58.38 |
+03:22:08.3 |
HIP 102929 |
13.58 |
| 2026-05-17 00:00 |
20:51:57.93 |
+03:22:18.3 |
HIP 102929 |
13.40 |
| 2026-05-17 12:00 |
20:51:57.47 |
+03:22:28.2 |
HIP 102929 |
13.21 |
| 2026-05-18 00:00 |
20:51:56.99 |
+03:22:37.9 |
HIP 102929 |
13.03 |
| 2026-05-18 12:00 |
20:51:56.49 |
+03:22:47.7 |
HIP 102929 |
12.84 |
| 2026-05-19 00:00 |
20:51:55.98 |
+03:22:57.3 |
HIP 102929 |
12.64 |
| 2026-05-19 12:00 |
20:51:55.45 |
+03:23:06.8 |
HIP 102929 |
12.45 |
| 2026-05-20 00:00 |
20:51:54.90 |
+03:23:16.2 |
HIP 102929 |
12.25 |
| 2026-05-20 12:00 |
20:51:54.34 |
+03:23:25.6 |
HIP 102929 |
12.05 |
| 2026-05-21 00:00 |
20:51:53.76 |
+03:23:34.8 |
HIP 102929 |
11.85 |
| 2026-05-21 12:00 |
20:51:53.16 |
+03:23:44.0 |
HIP 102929 |
11.65 |
| 2026-05-22 00:00 |
20:51:52.55 |
+03:23:53.0 |
HIP 102929 |
11.44 |
| 2026-05-22 12:00 |
20:51:51.92 |
+03:24:02.0 |
HIP 102929 |
11.23 |
| 2026-05-23 00:00 |
20:51:51.28 |
+03:24:10.9 |
HIP 102929 |
11.02 |
| 2026-05-23 12:00 |
20:51:50.62 |
+03:24:19.6 |
HIP 102929 |
10.80 |
| 2026-05-24 00:00 |
20:51:49.94 |
+03:24:28.3 |
HIP 102929 |
10.59 |
| 2026-05-24 12:00 |
20:51:49.25 |
+03:24:36.9 |
HIP 102929 |
10.37 |
| 2026-05-25 00:00 |
20:51:48.54 |
+03:24:45.4 |
HIP 102929 |
10.14 |
| 2026-05-25 12:00 |
20:51:47.82 |
+03:24:53.7 |
HIP 102929 |
9.92 |
| 2026-05-26 00:00 |
20:51:47.08 |
+03:25:02.0 |
HIP 102929 |
9.69 |
| 2026-05-26 12:00 |
20:51:46.32 |
+03:25:10.2 |
HIP 102929 |
9.46 |
| 2026-05-27 00:00 |
20:51:45.55 |
+03:25:18.3 |
HIP 102929 |
9.23 |
| 2026-05-27 12:00 |
20:51:44.76 |
+03:25:26.3 |
HIP 102929 |
8.99 |
| 2026-05-28 00:00 |
20:51:43.96 |
+03:25:34.2 |
HIP 102929 |
8.76 |
| 2026-05-28 12:00 |
20:51:43.14 |
+03:25:42.0 |
HIP 102929 |
8.52 |
| 2026-05-29 00:00 |
20:51:42.31 |
+03:25:49.7 |
HIP 102929 |
8.27 |
| 2026-05-29 12:00 |
20:51:41.46 |
+03:25:57.2 |
HIP 102929 |
8.03 |
| 2026-05-30 00:00 |
20:51:40.59 |
+03:26:04.7 |
HIP 102929 |
7.78 |
| 2026-05-30 12:00 |
20:51:39.71 |
+03:26:12.1 |
HIP 102929 |
7.53 |
| 2026-05-31 00:00 |
20:51:38.82 |
+03:26:19.4 |
HIP 102929 |
7.27 |
| 2026-05-31 12:00 |
20:51:37.91 |
+03:26:26.6 |
HIP 102929 |
7.02 |
| 2026-06-01 00:00 |
20:51:36.98 |
+03:26:33.6 |
HIP 102929 |
6.76 |
| 2026-06-01 12:00 |
20:51:36.04 |
+03:26:40.6 |
HIP 102929 |
6.50 |
| 2026-06-02 00:00 |
20:51:35.09 |
+03:26:47.5 |
HIP 102929 |
6.23 |