| 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) |
| 2026-03-26 00:00 |
20:51:14.10 |
+02:59:34.2 |
HIP 102929 |
29.86 |
| 2026-03-26 12:00 |
20:51:15.34 |
+02:59:48.9 |
HIP 102929 |
29.62 |
| 2026-03-27 00:00 |
20:51:16.57 |
+03:00:03.7 |
HIP 102929 |
29.38 |
| 2026-03-27 12:00 |
20:51:17.79 |
+03:00:18.4 |
HIP 102929 |
29.15 |
| 2026-03-28 00:00 |
20:51:18.99 |
+03:00:33.1 |
HIP 102929 |
28.92 |
| 2026-03-28 12:00 |
20:51:20.17 |
+03:00:47.9 |
HIP 102929 |
28.69 |
| 2026-03-29 00:00 |
20:51:21.34 |
+03:01:02.6 |
HIP 102929 |
28.47 |
| 2026-03-29 12:00 |
20:51:22.50 |
+03:01:17.3 |
HIP 102929 |
28.25 |
| 2026-03-30 00:00 |
20:51:23.64 |
+03:01:32.0 |
HIP 102929 |
28.03 |
| 2026-03-30 12:00 |
20:51:24.77 |
+03:01:46.7 |
HIP 102929 |
27.82 |
| 2026-03-31 00:00 |
20:51:25.89 |
+03:02:01.4 |
HIP 102929 |
27.61 |
| 2026-03-31 12:00 |
20:51:26.98 |
+03:02:16.1 |
HIP 102929 |
27.40 |
| 2026-04-01 00:00 |
20:51:28.07 |
+03:02:30.8 |
HIP 102929 |
27.19 |
| 2026-04-01 12:00 |
20:51:29.14 |
+03:02:45.4 |
HIP 102929 |
26.99 |
| 2026-04-02 00:00 |
20:51:30.19 |
+03:03:00.1 |
HIP 102929 |
26.79 |
| 2026-04-02 12:00 |
20:51:31.23 |
+03:03:14.7 |
HIP 102929 |
26.60 |
| 2026-04-03 00:00 |
20:51:32.25 |
+03:03:29.4 |
HIP 102929 |
26.40 |
| 2026-04-03 12:00 |
20:51:33.26 |
+03:03:44.0 |
HIP 102929 |
26.21 |
| 2026-04-04 00:00 |
20:51:34.25 |
+03:03:58.6 |
HIP 102929 |
26.02 |
| 2026-04-04 12:00 |
20:51:35.23 |
+03:04:13.2 |
HIP 102929 |
25.84 |
| 2026-04-05 00:00 |
20:51:36.20 |
+03:04:27.7 |
HIP 102929 |
25.66 |
| 2026-04-05 12:00 |
20:51:37.14 |
+03:04:42.3 |
HIP 102929 |
25.48 |
| 2026-04-06 00:00 |
20:51:38.07 |
+03:04:56.8 |
HIP 102929 |
25.30 |
| 2026-04-06 12:00 |
20:51:38.99 |
+03:05:11.3 |
HIP 102929 |
25.13 |
| 2026-04-07 00:00 |
20:51:39.89 |
+03:05:25.8 |
HIP 102929 |
24.95 |
| 2026-04-07 12:00 |
20:51:40.78 |
+03:05:40.3 |
HIP 102929 |
24.78 |
| 2026-04-08 00:00 |
20:51:41.65 |
+03:05:54.8 |
HIP 102929 |
24.62 |
| 2026-04-08 12:00 |
20:51:42.50 |
+03:06:09.2 |
HIP 102929 |
24.45 |
| 2026-04-09 00:00 |
20:51:43.34 |
+03:06:23.6 |
HIP 102929 |
24.29 |
| 2026-04-09 12:00 |
20:51:44.16 |
+03:06:38.0 |
HIP 102929 |
24.13 |
| 2026-04-10 00:00 |
20:51:44.96 |
+03:06:52.3 |
HIP 102929 |
23.97 |
| 2026-04-10 12:00 |
20:51:45.75 |
+03:07:06.7 |
HIP 102929 |
23.81 |
| 2026-04-11 00:00 |
20:51:46.53 |
+03:07:21.0 |
HIP 102929 |
23.66 |
| 2026-04-11 12:00 |
20:51:47.29 |
+03:07:35.3 |
HIP 102929 |
23.50 |
| 2026-04-12 00:00 |
20:51:48.03 |
+03:07:49.5 |
HIP 102929 |
23.35 |
| 2026-04-12 12:00 |
20:51:48.75 |
+03:08:03.7 |
HIP 102929 |
23.21 |
| 2026-04-13 00:00 |
20:51:49.46 |
+03:08:17.9 |
HIP 102929 |
23.06 |
| 2026-04-13 12:00 |
20:51:50.15 |
+03:08:32.0 |
HIP 102929 |
22.91 |
| 2026-04-14 00:00 |
20:51:50.83 |
+03:08:46.2 |
HIP 102929 |
22.77 |
| 2026-04-14 12:00 |
20:51:51.49 |
+03:09:00.2 |
HIP 102929 |
22.63 |
| 2026-04-15 00:00 |
20:51:52.13 |
+03:09:14.3 |
HIP 102929 |
22.49 |
| 2026-04-15 12:00 |
20:51:52.76 |
+03:09:28.3 |
HIP 102929 |
22.35 |
| 2026-04-16 00:00 |
20:51:53.37 |
+03:09:42.3 |
HIP 102929 |
22.21 |