C/1992 A1 (Helin-Alu)
| 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) |
| 2026-02-03 00:00 |
20:48:12.32 |
+02:37:28.0 |
HIP 102653 |
5.50 |
| 2026-02-03 12:00 |
20:48:14.42 |
+02:37:37.8 |
HIP 102653 |
5.43 |
| 2026-02-04 00:00 |
20:48:16.51 |
+02:37:47.7 |
HIP 102653 |
5.41 |
| 2026-02-04 12:00 |
20:48:18.60 |
+02:37:57.6 |
HIP 102653 |
5.44 |
| 2026-02-05 00:00 |
20:48:20.70 |
+02:38:07.7 |
HIP 102653 |
5.53 |
| 2026-02-05 12:00 |
20:48:22.78 |
+02:38:17.8 |
HIP 102653 |
5.67 |
| 2026-02-06 00:00 |
20:48:24.87 |
+02:38:28.0 |
HIP 102653 |
5.85 |
| 2026-02-06 12:00 |
20:48:26.95 |
+02:38:38.3 |
HIP 102653 |
6.08 |
| 2026-02-07 00:00 |
20:48:29.03 |
+02:38:48.7 |
HIP 102653 |
6.34 |
| 2026-02-07 12:00 |
20:48:31.11 |
+02:38:59.2 |
HIP 102653 |
6.64 |
| 2026-02-08 00:00 |
20:48:33.19 |
+02:39:09.8 |
HIP 102653 |
6.97 |
| 2026-02-08 12:00 |
20:48:35.26 |
+02:39:20.4 |
HIP 102653 |
7.32 |
| 2026-02-09 00:00 |
20:48:37.33 |
+02:39:31.2 |
HIP 102653 |
7.69 |
| 2026-02-09 12:00 |
20:48:39.40 |
+02:39:42.0 |
HIP 102653 |
8.09 |
| 2026-02-10 00:00 |
20:48:41.47 |
+02:39:52.9 |
HIP 102653 |
8.49 |
| 2026-02-10 12:00 |
20:48:43.53 |
+02:40:03.9 |
HIP 102653 |
8.92 |
| 2026-02-11 00:00 |
20:48:45.58 |
+02:40:14.9 |
HIP 102653 |
9.35 |
| 2026-02-11 12:00 |
20:48:47.64 |
+02:40:26.1 |
HIP 102653 |
9.79 |
| 2026-02-12 00:00 |
20:48:49.69 |
+02:40:37.3 |
HIP 102653 |
10.24 |
| 2026-02-12 12:00 |
20:48:51.73 |
+02:40:48.6 |
HIP 102653 |
10.70 |
| 2026-02-13 00:00 |
20:48:53.77 |
+02:41:00.0 |
HIP 102653 |
11.17 |
| 2026-02-13 12:00 |
20:48:55.81 |
+02:41:11.4 |
HIP 102653 |
11.64 |
| 2026-02-14 00:00 |
20:48:57.84 |
+02:41:22.9 |
HIP 102653 |
12.12 |
| 2026-02-14 12:00 |
20:48:59.87 |
+02:41:34.5 |
HIP 102653 |
12.60 |
| 2026-02-15 00:00 |
20:49:01.89 |
+02:41:46.2 |
HIP 102653 |
13.08 |
| 2026-02-15 12:00 |
20:49:03.91 |
+02:41:58.0 |
HIP 102653 |
13.57 |
| 2026-02-16 00:00 |
20:49:05.93 |
+02:42:09.8 |
HIP 102653 |
14.06 |
| 2026-02-16 12:00 |
20:49:07.93 |
+02:42:21.7 |
HIP 102653 |
14.55 |
| 2026-02-17 00:00 |
20:49:09.94 |
+02:42:33.7 |
HIP 102653 |
15.04 |
| 2026-02-17 12:00 |
20:49:11.93 |
+02:42:45.7 |
HIP 102653 |
15.54 |
| 2026-02-18 00:00 |
20:49:13.92 |
+02:42:57.8 |
HIP 102653 |
16.03 |
| 2026-02-18 12:00 |
20:49:15.91 |
+02:43:10.0 |
HIP 102653 |
16.53 |
| 2026-02-19 00:00 |
20:49:17.89 |
+02:43:22.2 |
HIP 102653 |
17.03 |
| 2026-02-19 12:00 |
20:49:19.86 |
+02:43:34.5 |
HIP 102653 |
17.53 |
| 2026-02-20 00:00 |
20:49:21.83 |
+02:43:46.9 |
HIP 102653 |
18.03 |
| 2026-02-20 12:00 |
20:49:23.79 |
+02:43:59.4 |
HIP 102653 |
18.53 |
| 2026-02-21 00:00 |
20:49:25.75 |
+02:44:11.9 |
HIP 102653 |
19.03 |
| 2026-02-21 12:00 |
20:49:27.69 |
+02:44:24.5 |
HIP 102653 |
19.53 |
| 2026-02-22 00:00 |
20:49:29.63 |
+02:44:37.1 |
HIP 102832 |
19.96 |
| 2026-02-22 12:00 |
20:49:31.57 |
+02:44:49.8 |
HIP 102832 |
19.99 |
| 2026-02-23 00:00 |
20:49:33.49 |
+02:45:02.5 |
HIP 102832 |
20.03 |
| 2026-02-23 12:00 |
20:49:35.41 |
+02:45:15.4 |
HIP 102832 |
20.09 |
| 2026-02-24 00:00 |
20:49:37.33 |
+02:45:28.2 |
HIP 102832 |
20.16 |