50P/Arend
| 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 |
-0.998 |
| 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) |
| 2026-02-03 00:00 |
12:27:09.04 |
-04:09:57.6 |
HIP 60680 |
24.21 |
| 2026-02-03 12:00 |
12:26:59.65 |
-04:10:02.8 |
HIP 60680 |
22.74 |
| 2026-02-04 00:00 |
12:26:50.05 |
-04:10:06.9 |
HIP 60680 |
21.43 |
| 2026-02-04 12:00 |
12:26:40.23 |
-04:10:09.6 |
HIP 60680 |
20.31 |
| 2026-02-05 00:00 |
12:26:30.20 |
-04:10:11.1 |
HIP 60680 |
19.44 |
| 2026-02-05 12:00 |
12:26:19.96 |
-04:10:11.3 |
HIP 60680 |
18.88 |
| 2026-02-06 00:00 |
12:26:09.51 |
-04:10:10.2 |
HIP 60574 |
17.88 |
| 2026-02-06 12:00 |
12:25:58.86 |
-04:10:07.9 |
HIP 60574 |
15.29 |
| 2026-02-07 00:00 |
12:25:47.99 |
-04:10:04.3 |
HIP 60574 |
12.68 |
| 2026-02-07 12:00 |
12:25:36.92 |
-04:09:59.5 |
HIP 60574 |
10.08 |
| 2026-02-08 00:00 |
12:25:25.64 |
-04:09:53.4 |
HIP 60574 |
7.55 |
| 2026-02-08 12:00 |
12:25:14.16 |
-04:09:46.0 |
HIP 60574 |
5.31 |
| 2026-02-09 00:00 |
12:25:02.47 |
-04:09:37.4 |
HIP 60574 |
3.98 |
| 2026-02-09 12:00 |
12:24:50.58 |
-04:09:27.5 |
HIP 60574 |
4.57 |
| 2026-02-10 00:00 |
12:24:38.49 |
-04:09:16.5 |
HIP 60574 |
6.65 |
| 2026-02-10 12:00 |
12:24:26.20 |
-04:09:04.1 |
HIP 60574 |
9.32 |
| 2026-02-11 00:00 |
12:24:13.71 |
-04:08:50.6 |
HIP 60574 |
12.23 |
| 2026-02-11 12:00 |
12:24:01.03 |
-04:08:35.8 |
HIP 60574 |
15.28 |
| 2026-02-12 00:00 |
12:23:48.15 |
-04:08:19.8 |
HIP 60574 |
18.42 |
| 2026-02-12 12:00 |
12:23:35.07 |
-04:08:02.6 |
HIP 60574 |
21.64 |
| 2026-02-13 00:00 |
12:23:21.80 |
-04:07:44.2 |
HIP 60574 |
24.92 |
| 2026-02-13 12:00 |
12:23:08.34 |
-04:07:24.5 |
HIP 60298 |
24.89 |
| 2026-02-14 00:00 |
12:22:54.69 |
-04:07:03.7 |
HIP 60298 |
22.61 |
| 2026-02-14 12:00 |
12:22:40.86 |
-04:06:41.7 |
HIP 60298 |
20.63 |
| 2026-02-15 00:00 |
12:22:26.84 |
-04:06:18.5 |
HIP 60298 |
19.08 |
| 2026-02-15 12:00 |
12:22:12.63 |
-04:05:54.2 |
HIP 60298 |
18.09 |
| 2026-02-16 00:00 |
12:21:58.24 |
-04:05:28.6 |
HIP 60298 |
17.79 |
| 2026-02-16 12:00 |
12:21:43.68 |
-04:05:02.0 |
HIP 60194 |
16.91 |
| 2026-02-17 00:00 |
12:21:28.93 |
-04:04:34.1 |
HIP 60194 |
13.29 |
| 2026-02-17 12:00 |
12:21:14.01 |
-04:04:05.2 |
HIP 60194 |
9.70 |
| 2026-02-18 00:00 |
12:20:58.91 |
-04:03:35.1 |
HIP 60194 |
6.24 |
| 2026-02-18 12:00 |
12:20:43.64 |
-04:03:03.8 |
HIP 60194 |
3.53 |
| 2026-02-19 00:00 |
12:20:28.21 |
-04:02:31.5 |
HIP 60194 |
3.96 |
| 2026-02-19 12:00 |
12:20:12.60 |
-04:01:58.1 |
HIP 60194 |
7.04 |
| 2026-02-20 00:00 |
12:19:56.83 |
-04:01:23.6 |
HIP 60194 |
10.73 |
| 2026-02-20 12:00 |
12:19:40.90 |
-04:00:48.0 |
HIP 60194 |
14.61 |
| 2026-02-21 00:00 |
12:19:24.81 |
-04:00:11.3 |
HIP 60194 |
18.59 |
| 2026-02-21 12:00 |
12:19:08.56 |
-03:59:33.6 |
HIP 59984 |
14.94 |
| 2026-02-22 00:00 |
12:18:52.16 |
-03:58:54.8 |
HIP 59984 |
10.80 |
| 2026-02-22 12:00 |
12:18:35.60 |
-03:58:15.0 |
HIP 59984 |
6.62 |
| 2026-02-23 00:00 |
12:18:18.90 |
-03:57:34.2 |
HIP 59984 |
2.41 |
| 2026-02-23 12:00 |
12:18:02.04 |
-03:56:52.4 |
HIP 59983 |
1.83 |
| 2026-02-24 00:00 |
12:17:45.05 |
-03:56:09.6 |
HIP 59983 |
6.13 |