85D/Boethin
| Parameter |
Value |
| Designation |
85D/Boethin |
| Type |
D |
| Perihelion (tp_cal, UTC) |
2008-12-12T17:55:03.103680Z |
| Orbit solution date (soln_date, UTC) |
2007-09-25T13:47:46Z |
| Obs used |
51 |
| NEO |
Yes |
| M1 |
- |
| K1 |
- |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2007-06-01.0000000 |
| e |
0.78116063 |
| q (au) |
1.134657 |
| a (au) |
5.184887 |
| i (deg) |
4.295295 |
| Ω (om, deg) |
359.396114 |
| ω (w, deg) |
37.618385 |
| M (ma, deg) |
313.187511 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.705 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.705 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.865 |
| k |
1.000 |
| δ90 |
9.984 |
| 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) |
| 2026-02-03 00:00 |
14:40:04.02 |
-19:32:52.8 |
HIP 71816 |
29.77 |
| 2026-02-03 12:00 |
14:40:05.84 |
-19:33:15.9 |
HIP 71816 |
29.20 |
| 2026-02-04 00:00 |
14:40:07.55 |
-19:33:38.5 |
HIP 71816 |
28.65 |
| 2026-02-04 12:00 |
14:40:09.14 |
-19:34:00.6 |
HIP 71816 |
28.13 |
| 2026-02-05 00:00 |
14:40:10.62 |
-19:34:22.2 |
HIP 71816 |
27.63 |
| 2026-02-05 12:00 |
14:40:11.99 |
-19:34:43.3 |
HIP 71816 |
27.15 |
| 2026-02-06 00:00 |
14:40:13.23 |
-19:35:03.9 |
HIP 71816 |
26.70 |
| 2026-02-06 12:00 |
14:40:14.36 |
-19:35:24.0 |
HIP 71816 |
26.28 |
| 2026-02-07 00:00 |
14:40:15.38 |
-19:35:43.6 |
HIP 71816 |
25.87 |
| 2026-02-07 12:00 |
14:40:16.28 |
-19:36:02.6 |
HIP 71816 |
25.49 |
| 2026-02-08 00:00 |
14:40:17.06 |
-19:36:21.2 |
HIP 71816 |
25.14 |
| 2026-02-08 12:00 |
14:40:17.72 |
-19:36:39.2 |
HIP 71816 |
24.81 |
| 2026-02-09 00:00 |
14:40:18.27 |
-19:36:56.8 |
HIP 71816 |
24.50 |
| 2026-02-09 12:00 |
14:40:18.69 |
-19:37:13.8 |
HIP 71816 |
24.22 |
| 2026-02-10 00:00 |
14:40:19.00 |
-19:37:30.3 |
HIP 71816 |
23.96 |
| 2026-02-10 12:00 |
14:40:19.19 |
-19:37:46.2 |
HIP 71816 |
23.73 |
| 2026-02-11 00:00 |
14:40:19.26 |
-19:38:01.7 |
HIP 71816 |
23.53 |
| 2026-02-11 12:00 |
14:40:19.22 |
-19:38:16.6 |
HIP 71816 |
23.35 |
| 2026-02-12 00:00 |
14:40:19.05 |
-19:38:31.0 |
HIP 71816 |
23.19 |
| 2026-02-12 12:00 |
14:40:18.76 |
-19:38:44.8 |
HIP 71816 |
23.07 |
| 2026-02-13 00:00 |
14:40:18.36 |
-19:38:58.2 |
HIP 71816 |
22.97 |
| 2026-02-13 12:00 |
14:40:17.83 |
-19:39:10.9 |
HIP 71816 |
22.90 |
| 2026-02-14 00:00 |
14:40:17.19 |
-19:39:23.2 |
HIP 71816 |
22.86 |
| 2026-02-14 12:00 |
14:40:16.43 |
-19:39:34.9 |
HIP 71816 |
22.85 |
| 2026-02-15 00:00 |
14:40:15.54 |
-19:39:46.1 |
HIP 71816 |
22.87 |
| 2026-02-15 12:00 |
14:40:14.54 |
-19:39:56.7 |
HIP 71816 |
22.92 |
| 2026-02-16 00:00 |
14:40:13.41 |
-19:40:06.8 |
HIP 71816 |
23.00 |
| 2026-02-16 12:00 |
14:40:12.16 |
-19:40:16.3 |
HIP 71816 |
23.11 |
| 2026-02-17 00:00 |
14:40:10.80 |
-19:40:25.3 |
HIP 71816 |
23.25 |
| 2026-02-17 12:00 |
14:40:09.31 |
-19:40:33.7 |
HIP 71816 |
23.42 |
| 2026-02-18 00:00 |
14:40:07.70 |
-19:40:41.6 |
HIP 71816 |
23.63 |
| 2026-02-18 12:00 |
14:40:05.98 |
-19:40:49.0 |
HIP 71816 |
23.87 |
| 2026-02-19 00:00 |
14:40:04.13 |
-19:40:55.8 |
HIP 71614 |
23.92 |
| 2026-02-19 12:00 |
14:40:02.16 |
-19:41:02.0 |
HIP 71614 |
23.50 |
| 2026-02-20 00:00 |
14:40:00.07 |
-19:41:07.7 |
HIP 71614 |
23.07 |
| 2026-02-20 12:00 |
14:39:57.86 |
-19:41:12.8 |
HIP 71614 |
22.63 |
| 2026-02-21 00:00 |
14:39:55.54 |
-19:41:17.3 |
HIP 71614 |
22.18 |
| 2026-02-21 12:00 |
14:39:53.09 |
-19:41:21.4 |
HIP 71614 |
21.71 |
| 2026-02-22 00:00 |
14:39:50.52 |
-19:41:24.8 |
HIP 71614 |
21.24 |
| 2026-02-22 12:00 |
14:39:47.83 |
-19:41:27.7 |
HIP 71614 |
20.77 |
| 2026-02-23 00:00 |
14:39:45.02 |
-19:41:30.0 |
HIP 71614 |
20.29 |
| 2026-02-23 12:00 |
14:39:42.09 |
-19:41:31.8 |
HIP 71614 |
19.81 |
| 2026-02-24 00:00 |
14:39:39.05 |
-19:41:33.0 |
HIP 71614 |
19.33 |