| 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 |
9.985 |
| 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) |
| 2026-09-20 00:00 |
14:14:18.99 |
-17:16:32.3 |
HIP 69548 |
11.40 |
| 2026-09-20 12:00 |
14:14:30.35 |
-17:17:22.9 |
HIP 69548 |
11.34 |
| 2026-09-21 00:00 |
14:14:41.76 |
-17:18:13.7 |
HIP 69548 |
11.97 |
| 2026-09-21 12:00 |
14:14:53.23 |
-17:19:04.8 |
HIP 69548 |
13.21 |
| 2026-09-22 00:00 |
14:15:04.75 |
-17:19:56.2 |
HIP 69548 |
14.91 |
| 2026-09-22 12:00 |
14:15:16.32 |
-17:20:48.0 |
HIP 69548 |
16.94 |
| 2026-09-23 00:00 |
14:15:27.94 |
-17:21:40.0 |
HIP 69548 |
19.20 |
| 2026-09-23 12:00 |
14:15:39.61 |
-17:22:32.3 |
HIP 69548 |
21.63 |
| 2026-09-24 00:00 |
14:15:51.34 |
-17:23:24.9 |
HIP 69548 |
24.18 |
| 2026-09-24 12:00 |
14:16:03.11 |
-17:24:17.8 |
HIP 69548 |
26.81 |
| 2026-09-25 00:00 |
14:16:14.93 |
-17:25:11.0 |
HIP 69821 |
25.77 |
| 2026-09-25 12:00 |
14:16:26.81 |
-17:26:04.4 |
HIP 69821 |
23.36 |
| 2026-09-26 00:00 |
14:16:38.73 |
-17:26:58.1 |
HIP 69821 |
21.09 |
| 2026-09-26 12:00 |
14:16:50.70 |
-17:27:52.2 |
HIP 69821 |
19.01 |
| 2026-09-27 00:00 |
14:17:02.72 |
-17:28:46.4 |
HIP 69821 |
17.18 |
| 2026-09-27 12:00 |
14:17:14.78 |
-17:29:41.0 |
HIP 69821 |
15.73 |
| 2026-09-28 00:00 |
14:17:26.89 |
-17:30:35.8 |
HIP 69821 |
14.74 |
| 2026-09-28 12:00 |
14:17:39.05 |
-17:31:30.9 |
HIP 69821 |
14.34 |
| 2026-09-29 00:00 |
14:17:51.25 |
-17:32:26.2 |
HIP 69821 |
14.58 |
| 2026-09-29 12:00 |
14:18:03.50 |
-17:33:21.8 |
HIP 69821 |
15.43 |
| 2026-09-30 00:00 |
14:18:15.79 |
-17:34:17.7 |
HIP 69821 |
16.80 |
| 2026-09-30 12:00 |
14:18:28.12 |
-17:35:13.8 |
HIP 69821 |
18.60 |
| 2026-10-01 00:00 |
14:18:40.50 |
-17:36:10.1 |
HIP 69821 |
20.71 |
| 2026-10-01 12:00 |
14:18:52.93 |
-17:37:06.7 |
HIP 69821 |
23.05 |
| 2026-10-02 00:00 |
14:19:05.39 |
-17:38:03.6 |
HIP 70078 |
20.60 |
| 2026-10-02 12:00 |
14:19:17.90 |
-17:39:00.7 |
HIP 70078 |
18.14 |
| 2026-10-03 00:00 |
14:19:30.45 |
-17:39:58.0 |
HIP 70078 |
15.93 |
| 2026-10-03 12:00 |
14:19:43.04 |
-17:40:55.5 |
HIP 70078 |
14.06 |
| 2026-10-04 00:00 |
14:19:55.67 |
-17:41:53.3 |
HIP 70078 |
12.71 |
| 2026-10-04 12:00 |
14:20:08.34 |
-17:42:51.4 |
HIP 70078 |
12.06 |
| 2026-10-05 00:00 |
14:20:21.05 |
-17:43:49.6 |
HIP 70129 |
10.19 |
| 2026-10-05 12:00 |
14:20:33.80 |
-17:44:48.1 |
HIP 70129 |
7.02 |
| 2026-10-06 00:00 |
14:20:46.59 |
-17:45:46.8 |
HIP 70129 |
3.85 |
| 2026-10-06 12:00 |
14:20:59.42 |
-17:46:45.7 |
HIP 70129 |
0.89 |
| 2026-10-07 00:00 |
14:21:12.28 |
-17:47:44.8 |
HIP 70129 |
2.73 |
| 2026-10-07 12:00 |
14:21:25.19 |
-17:48:44.2 |
HIP 70129 |
5.90 |
| 2026-10-08 00:00 |
14:21:38.12 |
-17:49:43.7 |
HIP 70129 |
9.13 |
| 2026-10-08 12:00 |
14:21:51.10 |
-17:50:43.5 |
HIP 70129 |
12.36 |
| 2026-10-09 00:00 |
14:22:04.10 |
-17:51:43.4 |
HIP 70129 |
15.61 |
| 2026-10-09 12:00 |
14:22:17.15 |
-17:52:43.6 |
HIP 70288 |
13.30 |
| 2026-10-10 00:00 |
14:22:30.22 |
-17:53:43.9 |
HIP 70288 |
10.83 |
| 2026-10-10 12:00 |
14:22:43.33 |
-17:54:44.4 |
HIP 70288 |
8.89 |
| 2026-10-11 00:00 |
14:22:56.47 |
-17:55:45.2 |
HIP 70288 |
7.88 |