| Parameter |
Value |
| Designation |
C/1939 H1 (Jurlof-Achmarof-Hassel) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
1939-04-10T02:44:02.135040Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:29:05Z |
| Obs used |
14 |
| NEO |
- |
| M1 |
6.000 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
1939-05-07.0000000 |
| e |
0.99150316 |
| q (au) |
0.528255 |
| a (au) |
62.170794 |
| i (deg) |
138.167852 |
| Ω (om, deg) |
312.348989 |
| ω (w, deg) |
89.151721 |
| M (ma, deg) |
0.054057 |
Magnitude
Scatter + Global Linear
$$
M_a = (5.872 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
5.872 |
| n |
2.000 |
| gf |
0.800 |
| gb |
-0.500 |
| k |
0.965 |
| δ90 |
1.000 |
| 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) |
| 2026-09-20 00:00 |
03:55:32.56 |
-22:35:16.7 |
HIP 18248 |
23.10 |
| 2026-09-20 12:00 |
03:55:31.90 |
-22:35:30.5 |
HIP 18248 |
23.09 |
| 2026-09-21 00:00 |
03:55:31.22 |
-22:35:44.3 |
HIP 18248 |
23.09 |
| 2026-09-21 12:00 |
03:55:30.53 |
-22:35:58.1 |
HIP 18248 |
23.09 |
| 2026-09-22 00:00 |
03:55:29.83 |
-22:36:11.8 |
HIP 18248 |
23.09 |
| 2026-09-22 12:00 |
03:55:29.12 |
-22:36:25.5 |
HIP 18248 |
23.09 |
| 2026-09-23 00:00 |
03:55:28.40 |
-22:36:39.2 |
HIP 18248 |
23.09 |
| 2026-09-23 12:00 |
03:55:27.67 |
-22:36:52.9 |
HIP 18248 |
23.09 |
| 2026-09-24 00:00 |
03:55:26.93 |
-22:37:06.5 |
HIP 18248 |
23.09 |
| 2026-09-24 12:00 |
03:55:26.17 |
-22:37:20.0 |
HIP 18248 |
23.10 |
| 2026-09-25 00:00 |
03:55:25.41 |
-22:37:33.6 |
HIP 18248 |
23.10 |
| 2026-09-25 12:00 |
03:55:24.63 |
-22:37:47.1 |
HIP 18248 |
23.11 |
| 2026-09-26 00:00 |
03:55:23.85 |
-22:38:00.5 |
HIP 18248 |
23.12 |
| 2026-09-26 12:00 |
03:55:23.05 |
-22:38:13.9 |
HIP 18248 |
23.13 |
| 2026-09-27 00:00 |
03:55:22.25 |
-22:38:27.3 |
HIP 18248 |
23.14 |
| 2026-09-27 12:00 |
03:55:21.43 |
-22:38:40.7 |
HIP 18248 |
23.15 |
| 2026-09-28 00:00 |
03:55:20.60 |
-22:38:54.0 |
HIP 18248 |
23.17 |
| 2026-09-28 12:00 |
03:55:19.76 |
-22:39:07.2 |
HIP 18248 |
23.18 |
| 2026-09-29 00:00 |
03:55:18.92 |
-22:39:20.4 |
HIP 18248 |
23.20 |
| 2026-09-29 12:00 |
03:55:18.06 |
-22:39:33.6 |
HIP 18248 |
23.22 |
| 2026-09-30 00:00 |
03:55:17.19 |
-22:39:46.7 |
HIP 18248 |
23.24 |
| 2026-09-30 12:00 |
03:55:16.31 |
-22:39:59.8 |
HIP 18248 |
23.26 |
| 2026-10-01 00:00 |
03:55:15.42 |
-22:40:12.8 |
HIP 18248 |
23.28 |
| 2026-10-01 12:00 |
03:55:14.52 |
-22:40:25.8 |
HIP 18248 |
23.31 |
| 2026-10-02 00:00 |
03:55:13.61 |
-22:40:38.7 |
HIP 18248 |
23.33 |
| 2026-10-02 12:00 |
03:55:12.69 |
-22:40:51.6 |
HIP 18248 |
23.36 |
| 2026-10-03 00:00 |
03:55:11.77 |
-22:41:04.5 |
HIP 18248 |
23.39 |
| 2026-10-03 12:00 |
03:55:10.83 |
-22:41:17.2 |
HIP 18248 |
23.42 |
| 2026-10-04 00:00 |
03:55:09.88 |
-22:41:30.0 |
HIP 18248 |
23.46 |
| 2026-10-04 12:00 |
03:55:08.92 |
-22:41:42.6 |
HIP 18248 |
23.49 |
| 2026-10-05 00:00 |
03:55:07.95 |
-22:41:55.2 |
HIP 18248 |
23.53 |
| 2026-10-05 12:00 |
03:55:06.97 |
-22:42:07.8 |
HIP 18248 |
23.57 |
| 2026-10-06 00:00 |
03:55:05.99 |
-22:42:20.3 |
HIP 18248 |
23.61 |
| 2026-10-06 12:00 |
03:55:04.99 |
-22:42:32.7 |
HIP 18248 |
23.66 |
| 2026-10-07 00:00 |
03:55:03.98 |
-22:42:45.1 |
HIP 18248 |
23.70 |
| 2026-10-07 12:00 |
03:55:02.97 |
-22:42:57.4 |
HIP 18248 |
23.75 |
| 2026-10-08 00:00 |
03:55:01.94 |
-22:43:09.7 |
HIP 18248 |
23.80 |
| 2026-10-08 12:00 |
03:55:00.91 |
-22:43:21.9 |
HIP 18248 |
23.85 |
| 2026-10-09 00:00 |
03:54:59.86 |
-22:43:34.0 |
HIP 18248 |
23.90 |
| 2026-10-09 12:00 |
03:54:58.81 |
-22:43:46.1 |
HIP 18248 |
23.96 |
| 2026-10-10 00:00 |
03:54:57.75 |
-22:43:58.1 |
HIP 18248 |
24.02 |
| 2026-10-10 12:00 |
03:54:56.68 |
-22:44:10.0 |
HIP 18248 |
24.08 |
| 2026-10-11 00:00 |
03:54:55.60 |
-22:44:21.9 |
HIP 18248 |
24.14 |