| 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) |
| 2026-05-12 00:00 |
03:52:38.22 |
-22:03:05.5 |
HIP 18143 |
10.04 |
| 2026-05-12 12:00 |
03:52:39.59 |
-22:03:00.2 |
HIP 18143 |
9.91 |
| 2026-05-13 00:00 |
03:52:40.96 |
-22:02:55.1 |
HIP 18143 |
9.80 |
| 2026-05-13 12:00 |
03:52:42.33 |
-22:02:50.0 |
HIP 18143 |
9.69 |
| 2026-05-14 00:00 |
03:52:43.71 |
-22:02:45.1 |
HIP 18143 |
9.60 |
| 2026-05-14 12:00 |
03:52:45.08 |
-22:02:40.2 |
HIP 18143 |
9.52 |
| 2026-05-15 00:00 |
03:52:46.46 |
-22:02:35.5 |
HIP 18143 |
9.45 |
| 2026-05-15 12:00 |
03:52:47.84 |
-22:02:30.9 |
HIP 18143 |
9.40 |
| 2026-05-16 00:00 |
03:52:49.22 |
-22:02:26.4 |
HIP 18143 |
9.36 |
| 2026-05-16 12:00 |
03:52:50.60 |
-22:02:22.0 |
HIP 18143 |
9.33 |
| 2026-05-17 00:00 |
03:52:51.98 |
-22:02:17.7 |
HIP 18143 |
9.32 |
| 2026-05-17 12:00 |
03:52:53.36 |
-22:02:13.5 |
HIP 18143 |
9.32 |
| 2026-05-18 00:00 |
03:52:54.75 |
-22:02:09.4 |
HIP 18143 |
9.33 |
| 2026-05-18 12:00 |
03:52:56.13 |
-22:02:05.5 |
HIP 18143 |
9.36 |
| 2026-05-19 00:00 |
03:52:57.52 |
-22:02:01.7 |
HIP 18143 |
9.40 |
| 2026-05-19 12:00 |
03:52:58.90 |
-22:01:57.9 |
HIP 18143 |
9.45 |
| 2026-05-20 00:00 |
03:53:00.29 |
-22:01:54.3 |
HIP 18143 |
9.51 |
| 2026-05-20 12:00 |
03:53:01.67 |
-22:01:50.8 |
HIP 18143 |
9.59 |
| 2026-05-21 00:00 |
03:53:03.06 |
-22:01:47.4 |
HIP 18143 |
9.68 |
| 2026-05-21 12:00 |
03:53:04.44 |
-22:01:44.2 |
HIP 18143 |
9.78 |
| 2026-05-22 00:00 |
03:53:05.83 |
-22:01:41.0 |
HIP 18143 |
9.89 |
| 2026-05-22 12:00 |
03:53:07.22 |
-22:01:38.0 |
HIP 18143 |
10.02 |
| 2026-05-23 00:00 |
03:53:08.60 |
-22:01:35.0 |
HIP 18143 |
10.15 |
| 2026-05-23 12:00 |
03:53:09.99 |
-22:01:32.2 |
HIP 18143 |
10.30 |
| 2026-05-24 00:00 |
03:53:11.37 |
-22:01:29.5 |
HIP 18143 |
10.45 |
| 2026-05-24 12:00 |
03:53:12.76 |
-22:01:26.9 |
HIP 18143 |
10.61 |
| 2026-05-25 00:00 |
03:53:14.14 |
-22:01:24.5 |
HIP 18143 |
10.78 |
| 2026-05-25 12:00 |
03:53:15.53 |
-22:01:22.1 |
HIP 18143 |
10.96 |
| 2026-05-26 00:00 |
03:53:16.91 |
-22:01:19.8 |
HIP 18143 |
11.15 |
| 2026-05-26 12:00 |
03:53:18.29 |
-22:01:17.7 |
HIP 18143 |
11.35 |
| 2026-05-27 00:00 |
03:53:19.67 |
-22:01:15.7 |
HIP 18143 |
11.55 |
| 2026-05-27 12:00 |
03:53:21.05 |
-22:01:13.8 |
HIP 18143 |
11.76 |
| 2026-05-28 00:00 |
03:53:22.43 |
-22:01:12.0 |
HIP 18143 |
11.97 |
| 2026-05-28 12:00 |
03:53:23.81 |
-22:01:10.3 |
HIP 18143 |
12.19 |
| 2026-05-29 00:00 |
03:53:25.19 |
-22:01:08.8 |
HIP 18143 |
12.42 |
| 2026-05-29 12:00 |
03:53:26.56 |
-22:01:07.3 |
HIP 18143 |
12.65 |
| 2026-05-30 00:00 |
03:53:27.93 |
-22:01:06.0 |
HIP 18143 |
12.88 |
| 2026-05-30 12:00 |
03:53:29.31 |
-22:01:04.8 |
HIP 18143 |
13.12 |
| 2026-05-31 00:00 |
03:53:30.68 |
-22:01:03.7 |
HIP 18143 |
13.36 |
| 2026-05-31 12:00 |
03:53:32.05 |
-22:01:02.7 |
HIP 18143 |
13.61 |
| 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 |