| Parameter |
Value |
| Designation |
50P/Arend |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2007-11-02T19:43:29.481600Z |
| Orbit solution date (soln_date, UTC) |
2025-10-01T16:07:23Z |
| Obs used |
1874 |
| NEO |
- |
| M1 |
13.900 |
| K1 |
9.000 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-07-01.0000000 |
| e |
0.53063813 |
| q (au) |
1.918329 |
| a (au) |
4.087100 |
| i (deg) |
19.155639 |
| Ω (om, deg) |
355.310553 |
| ω (w, deg) |
49.039728 |
| M (ma, deg) |
159.384273 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.457 + 4.038\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.457 |
| n |
4.038 |
| gf |
1.000 |
| gb |
-1.000 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2023-08-17 |
2024-05-13 |
+13.6006 |
-5.552 |
| 2024-05-13 |
2025-05-02 |
-14.3888 |
+6.578 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
11:34:29.15 |
-01:36:38.1 |
HIP 56493 |
37.65 |
| 2026-06-01 12:00 |
11:34:30.93 |
-01:37:08.6 |
HIP 56493 |
37.08 |
| 2026-06-02 00:00 |
11:34:32.89 |
-01:37:40.0 |
HIP 56493 |
36.49 |
| 2026-06-02 12:00 |
11:34:35.03 |
-01:38:12.4 |
HIP 56493 |
35.88 |
| 2026-06-03 00:00 |
11:34:37.34 |
-01:38:45.9 |
HIP 56493 |
35.26 |
| 2026-06-03 12:00 |
11:34:39.83 |
-01:39:20.4 |
HIP 56493 |
34.63 |
| 2026-06-04 00:00 |
11:34:42.50 |
-01:39:55.9 |
HIP 56493 |
33.98 |
| 2026-06-04 12:00 |
11:34:45.34 |
-01:40:32.4 |
HIP 56493 |
33.33 |
| 2026-06-05 00:00 |
11:34:48.35 |
-01:41:09.9 |
HIP 56493 |
32.67 |
| 2026-06-05 12:00 |
11:34:51.54 |
-01:41:48.5 |
HIP 56493 |
32.01 |
| 2026-06-06 00:00 |
11:34:54.90 |
-01:42:28.0 |
HIP 56493 |
31.35 |
| 2026-06-06 12:00 |
11:34:58.43 |
-01:43:08.5 |
HIP 56493 |
30.71 |
| 2026-06-07 00:00 |
11:35:02.14 |
-01:43:50.1 |
HIP 56493 |
30.07 |
| 2026-06-07 12:00 |
11:35:06.01 |
-01:44:32.6 |
HIP 56493 |
29.46 |
| 2026-06-08 00:00 |
11:35:10.06 |
-01:45:16.1 |
HIP 56493 |
28.87 |
| 2026-06-08 12:00 |
11:35:14.27 |
-01:46:00.6 |
HIP 56493 |
28.32 |
| 2026-06-09 00:00 |
11:35:18.65 |
-01:46:46.1 |
HIP 56493 |
27.81 |
| 2026-06-09 12:00 |
11:35:23.20 |
-01:47:32.6 |
HIP 56493 |
27.35 |
| 2026-06-10 00:00 |
11:35:27.91 |
-01:48:20.1 |
HIP 56493 |
26.95 |
| 2026-06-10 12:00 |
11:35:32.80 |
-01:49:08.5 |
HIP 56493 |
26.62 |
| 2026-06-11 00:00 |
11:35:37.84 |
-01:49:57.9 |
HIP 56493 |
26.37 |
| 2026-06-11 12:00 |
11:35:43.05 |
-01:50:48.3 |
HIP 56493 |
26.22 |
| 2026-06-12 00:00 |
11:35:48.43 |
-01:51:39.7 |
HIP 56493 |
26.16 |
| 2026-06-12 12:00 |
11:35:53.97 |
-01:52:32.1 |
HIP 56493 |
26.20 |
| 2026-06-13 00:00 |
11:35:59.67 |
-01:53:25.4 |
HIP 56493 |
26.37 |
| 2026-06-13 12:00 |
11:36:05.53 |
-01:54:19.7 |
HIP 56493 |
26.65 |
| 2026-06-14 00:00 |
11:36:11.55 |
-01:55:14.9 |
HIP 56493 |
27.06 |
| 2026-06-14 12:00 |
11:36:17.73 |
-01:56:11.1 |
HIP 56493 |
27.59 |
| 2026-06-15 00:00 |
11:36:24.07 |
-01:57:08.3 |
HIP 56493 |
28.25 |
| 2026-06-15 12:00 |
11:36:30.57 |
-01:58:06.4 |
HIP 56493 |
29.05 |
| 2026-06-16 00:00 |
11:36:37.22 |
-01:59:05.5 |
HIP 56493 |
29.96 |
| 2026-06-16 12:00 |
11:36:44.03 |
-02:00:05.5 |
HIP 56738 |
30.57 |
| 2026-06-17 00:00 |
11:36:51.00 |
-02:01:06.5 |
HIP 56738 |
30.37 |
| 2026-06-17 12:00 |
11:36:58.12 |
-02:02:08.4 |
HIP 56738 |
30.29 |
| 2026-06-18 00:00 |
11:37:05.39 |
-02:03:11.2 |
HIP 56775 |
30.23 |
| 2026-06-18 12:00 |
11:37:12.82 |
-02:04:14.9 |
HIP 56775 |
28.23 |
| 2026-06-19 00:00 |
11:37:20.39 |
-02:05:19.6 |
HIP 56775 |
26.21 |
| 2026-06-19 12:00 |
11:37:28.12 |
-02:06:25.2 |
HIP 56775 |
24.19 |
| 2026-06-20 00:00 |
11:37:35.99 |
-02:07:31.7 |
HIP 56775 |
22.17 |
| 2026-06-20 12:00 |
11:37:44.01 |
-02:08:39.2 |
HIP 56775 |
20.16 |
| 2026-06-21 00:00 |
11:37:52.18 |
-02:09:47.5 |
HIP 56775 |
18.20 |
| 2026-06-21 12:00 |
11:38:00.50 |
-02:10:56.7 |
HIP 56775 |
16.31 |
| 2026-06-22 00:00 |
11:38:08.96 |
-02:12:06.8 |
HIP 56775 |
14.54 |