| 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) |
| 2026-06-01 00:00 |
03:53:33.41 |
-22:01:01.8 |
HIP 18143 |
13.86 |
| 2026-06-01 12:00 |
03:53:34.78 |
-22:01:01.1 |
HIP 18143 |
14.12 |
| 2026-06-02 00:00 |
03:53:36.14 |
-22:01:00.4 |
HIP 18143 |
14.38 |
| 2026-06-02 12:00 |
03:53:37.50 |
-22:00:59.9 |
HIP 18143 |
14.64 |
| 2026-06-03 00:00 |
03:53:38.86 |
-22:00:59.5 |
HIP 18143 |
14.90 |
| 2026-06-03 12:00 |
03:53:40.21 |
-22:00:59.2 |
HIP 18143 |
15.17 |
| 2026-06-04 00:00 |
03:53:41.57 |
-22:00:59.0 |
HIP 18143 |
15.43 |
| 2026-06-04 12:00 |
03:53:42.92 |
-22:00:58.9 |
HIP 18143 |
15.70 |
| 2026-06-05 00:00 |
03:53:44.27 |
-22:00:59.0 |
HIP 18143 |
15.98 |
| 2026-06-05 12:00 |
03:53:45.61 |
-22:00:59.2 |
HIP 18143 |
16.25 |
| 2026-06-06 00:00 |
03:53:46.96 |
-22:00:59.4 |
HIP 18143 |
16.53 |
| 2026-06-06 12:00 |
03:53:48.30 |
-22:00:59.8 |
HIP 18143 |
16.80 |
| 2026-06-07 00:00 |
03:53:49.64 |
-22:01:00.3 |
HIP 18143 |
17.08 |
| 2026-06-07 12:00 |
03:53:50.97 |
-22:01:01.0 |
HIP 18143 |
17.36 |
| 2026-06-08 00:00 |
03:53:52.30 |
-22:01:01.7 |
HIP 18143 |
17.64 |
| 2026-06-08 12:00 |
03:53:53.63 |
-22:01:02.6 |
HIP 18143 |
17.93 |
| 2026-06-09 00:00 |
03:53:54.96 |
-22:01:03.5 |
HIP 18143 |
18.21 |
| 2026-06-09 12:00 |
03:53:56.28 |
-22:01:04.6 |
HIP 18143 |
18.49 |
| 2026-06-10 00:00 |
03:53:57.60 |
-22:01:05.8 |
HIP 18143 |
18.78 |
| 2026-06-10 12:00 |
03:53:58.91 |
-22:01:07.2 |
HIP 18143 |
19.06 |
| 2026-06-11 00:00 |
03:54:00.22 |
-22:01:08.6 |
HIP 18143 |
19.35 |
| 2026-06-11 12:00 |
03:54:01.53 |
-22:01:10.1 |
HIP 18143 |
19.64 |
| 2026-06-12 00:00 |
03:54:02.83 |
-22:01:11.8 |
HIP 18143 |
19.93 |
| 2026-06-12 12:00 |
03:54:04.13 |
-22:01:13.6 |
HIP 18143 |
20.21 |
| 2026-06-13 00:00 |
03:54:05.43 |
-22:01:15.5 |
HIP 18143 |
20.50 |
| 2026-06-13 12:00 |
03:54:06.72 |
-22:01:17.5 |
HIP 18143 |
20.79 |
| 2026-06-14 00:00 |
03:54:08.01 |
-22:01:19.6 |
HIP 18143 |
21.08 |
| 2026-06-14 12:00 |
03:54:09.29 |
-22:01:21.9 |
HIP 18143 |
21.37 |
| 2026-06-15 00:00 |
03:54:10.57 |
-22:01:24.2 |
HIP 18248 |
21.44 |
| 2026-06-15 12:00 |
03:54:11.84 |
-22:01:26.7 |
HIP 18248 |
21.41 |
| 2026-06-16 00:00 |
03:54:13.11 |
-22:01:29.3 |
HIP 18248 |
21.38 |
| 2026-06-16 12:00 |
03:54:14.38 |
-22:01:32.0 |
HIP 18248 |
21.35 |
| 2026-06-17 00:00 |
03:54:15.63 |
-22:01:34.8 |
HIP 18248 |
21.32 |
| 2026-06-17 12:00 |
03:54:16.89 |
-22:01:37.8 |
HIP 18248 |
21.30 |
| 2026-06-18 00:00 |
03:54:18.14 |
-22:01:40.8 |
HIP 18248 |
21.28 |
| 2026-06-18 12:00 |
03:54:19.38 |
-22:01:44.0 |
HIP 18248 |
21.26 |
| 2026-06-19 00:00 |
03:54:20.62 |
-22:01:47.2 |
HIP 18248 |
21.24 |
| 2026-06-19 12:00 |
03:54:21.86 |
-22:01:50.6 |
HIP 18248 |
21.22 |
| 2026-06-20 00:00 |
03:54:23.09 |
-22:01:54.1 |
HIP 18248 |
21.21 |
| 2026-06-20 12:00 |
03:54:24.31 |
-22:01:57.7 |
HIP 18248 |
21.20 |
| 2026-06-21 00:00 |
03:54:25.53 |
-22:02:01.4 |
HIP 18248 |
21.19 |
| 2026-06-21 12:00 |
03:54:26.74 |
-22:02:05.3 |
HIP 18248 |
21.18 |
| 2026-06-22 00:00 |
03:54:27.95 |
-22:02:09.2 |
HIP 18248 |
21.17 |