| 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) |
| 2026-03-26 00:00 |
03:50:50.98 |
-22:18:13.3 |
HIP 18153 |
27.52 |
| 2026-03-26 12:00 |
03:50:51.77 |
-22:18:00.3 |
HIP 18153 |
27.33 |
| 2026-03-27 00:00 |
03:50:52.58 |
-22:17:47.3 |
HIP 18153 |
27.13 |
| 2026-03-27 12:00 |
03:50:53.39 |
-22:17:34.4 |
HIP 18153 |
26.94 |
| 2026-03-28 00:00 |
03:50:54.21 |
-22:17:21.6 |
HIP 18153 |
26.74 |
| 2026-03-28 12:00 |
03:50:55.04 |
-22:17:08.7 |
HIP 18153 |
26.54 |
| 2026-03-29 00:00 |
03:50:55.88 |
-22:16:56.0 |
HIP 18153 |
26.35 |
| 2026-03-29 12:00 |
03:50:56.73 |
-22:16:43.3 |
HIP 18153 |
26.15 |
| 2026-03-30 00:00 |
03:50:57.59 |
-22:16:30.7 |
HIP 18153 |
25.95 |
| 2026-03-30 12:00 |
03:50:58.46 |
-22:16:18.1 |
HIP 18153 |
25.75 |
| 2026-03-31 00:00 |
03:50:59.34 |
-22:16:05.5 |
HIP 18153 |
25.55 |
| 2026-03-31 12:00 |
03:51:00.23 |
-22:15:53.0 |
HIP 18153 |
25.35 |
| 2026-04-01 00:00 |
03:51:01.13 |
-22:15:40.6 |
HIP 18153 |
25.15 |
| 2026-04-01 12:00 |
03:51:02.03 |
-22:15:28.3 |
HIP 18153 |
24.95 |
| 2026-04-02 00:00 |
03:51:02.95 |
-22:15:15.9 |
HIP 18153 |
24.75 |
| 2026-04-02 12:00 |
03:51:03.87 |
-22:15:03.7 |
HIP 18153 |
24.55 |
| 2026-04-03 00:00 |
03:51:04.80 |
-22:14:51.5 |
HIP 18153 |
24.34 |
| 2026-04-03 12:00 |
03:51:05.75 |
-22:14:39.4 |
HIP 18153 |
24.14 |
| 2026-04-04 00:00 |
03:51:06.70 |
-22:14:27.3 |
HIP 18153 |
23.94 |
| 2026-04-04 12:00 |
03:51:07.66 |
-22:14:15.3 |
HIP 18153 |
23.74 |
| 2026-04-05 00:00 |
03:51:08.62 |
-22:14:03.4 |
HIP 18153 |
23.54 |
| 2026-04-05 12:00 |
03:51:09.60 |
-22:13:51.5 |
HIP 18153 |
23.33 |
| 2026-04-06 00:00 |
03:51:10.58 |
-22:13:39.7 |
HIP 18153 |
23.13 |
| 2026-04-06 12:00 |
03:51:11.58 |
-22:13:27.9 |
HIP 18153 |
22.93 |
| 2026-04-07 00:00 |
03:51:12.58 |
-22:13:16.2 |
HIP 18153 |
22.73 |
| 2026-04-07 12:00 |
03:51:13.59 |
-22:13:04.6 |
HIP 18153 |
22.53 |
| 2026-04-08 00:00 |
03:51:14.60 |
-22:12:53.1 |
HIP 18153 |
22.33 |
| 2026-04-08 12:00 |
03:51:15.63 |
-22:12:41.6 |
HIP 18153 |
22.13 |
| 2026-04-09 00:00 |
03:51:16.66 |
-22:12:30.2 |
HIP 18153 |
21.93 |
| 2026-04-09 12:00 |
03:51:17.71 |
-22:12:18.8 |
HIP 18153 |
21.73 |
| 2026-04-10 00:00 |
03:51:18.75 |
-22:12:07.6 |
HIP 18153 |
21.53 |
| 2026-04-10 12:00 |
03:51:19.81 |
-22:11:56.4 |
HIP 18153 |
21.33 |
| 2026-04-11 00:00 |
03:51:20.88 |
-22:11:45.2 |
HIP 18153 |
21.13 |
| 2026-04-11 12:00 |
03:51:21.95 |
-22:11:34.2 |
HIP 18153 |
20.93 |
| 2026-04-12 00:00 |
03:51:23.03 |
-22:11:23.2 |
HIP 18153 |
20.73 |
| 2026-04-12 12:00 |
03:51:24.12 |
-22:11:12.3 |
HIP 18153 |
20.54 |
| 2026-04-13 00:00 |
03:51:25.21 |
-22:11:01.5 |
HIP 18153 |
20.34 |
| 2026-04-13 12:00 |
03:51:26.31 |
-22:10:50.7 |
HIP 18153 |
20.15 |
| 2026-04-14 00:00 |
03:51:27.42 |
-22:10:40.0 |
HIP 18153 |
19.95 |
| 2026-04-14 12:00 |
03:51:28.54 |
-22:10:29.4 |
HIP 18153 |
19.76 |
| 2026-04-15 00:00 |
03:51:29.66 |
-22:10:18.9 |
HIP 18153 |
19.57 |
| 2026-04-15 12:00 |
03:51:30.79 |
-22:10:08.5 |
HIP 18153 |
19.38 |
| 2026-04-16 00:00 |
03:51:31.93 |
-22:09:58.1 |
HIP 18153 |
19.19 |