| Parameter |
Value |
| Designation |
139P/Vaisala-Oterma |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2008-04-20T10:37:01.891200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:27:39Z |
| Obs used |
546 |
| NEO |
- |
| M1 |
7.200 |
| K1 |
18.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2010-11-16.0000000 |
| e |
0.24752589 |
| q (au) |
3.402921 |
| a (au) |
4.522310 |
| i (deg) |
2.328730 |
| Ω (om, deg) |
242.377585 |
| ω (w, deg) |
165.725397 |
| M (ma, deg) |
96.291288 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.897 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.897 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
23:40:58.03 |
+00:21:46.0 |
HIP 116823 |
5.47 |
| 2026-06-01 12:00 |
23:41:19.78 |
+00:24:20.5 |
HIP 116823 |
9.89 |
| 2026-06-02 00:00 |
23:41:41.40 |
+00:26:54.2 |
HIP 116823 |
15.40 |
| 2026-06-02 12:00 |
23:42:02.89 |
+00:29:27.1 |
HIP 116984 |
20.17 |
| 2026-06-03 00:00 |
23:42:24.25 |
+00:31:59.3 |
HIP 116984 |
19.37 |
| 2026-06-03 12:00 |
23:42:45.49 |
+00:34:30.8 |
HIP 116984 |
20.32 |
| 2026-06-04 00:00 |
23:43:06.58 |
+00:37:01.4 |
HIP 117013 |
17.37 |
| 2026-06-04 12:00 |
23:43:27.55 |
+00:39:31.3 |
HIP 117097 |
13.07 |
| 2026-06-05 00:00 |
23:43:48.37 |
+00:42:00.4 |
HIP 117097 |
7.50 |
| 2026-06-05 12:00 |
23:44:09.07 |
+00:44:28.6 |
HIP 117097 |
2.87 |
| 2026-06-06 00:00 |
23:44:29.62 |
+00:46:56.1 |
HIP 117097 |
5.07 |
| 2026-06-06 12:00 |
23:44:50.04 |
+00:49:22.8 |
HIP 117097 |
10.36 |
| 2026-06-07 00:00 |
23:45:10.32 |
+00:51:48.6 |
HIP 117097 |
15.87 |
| 2026-06-07 12:00 |
23:45:30.46 |
+00:54:13.7 |
HIP 117097 |
21.40 |
| 2026-06-08 00:00 |
23:45:50.46 |
+00:56:37.8 |
HIP 117097 |
26.92 |
| 2026-06-08 12:00 |
23:46:10.31 |
+00:59:01.2 |
HIP 117260 |
27.88 |
| 2026-06-09 00:00 |
23:46:30.02 |
+01:01:23.6 |
HIP 117260 |
29.61 |
| 2026-06-09 12:00 |
23:46:49.59 |
+01:03:45.3 |
HIP 117260 |
32.17 |
| 2026-06-10 00:00 |
23:47:09.01 |
+01:06:06.0 |
HIP 117491 |
34.64 |
| 2026-06-10 12:00 |
23:47:28.29 |
+01:08:25.9 |
HIP 117491 |
30.04 |
| 2026-06-11 00:00 |
23:47:47.41 |
+01:10:44.8 |
HIP 117491 |
25.76 |
| 2026-06-11 12:00 |
23:48:06.39 |
+01:13:02.9 |
HIP 117491 |
21.97 |
| 2026-06-12 00:00 |
23:48:25.22 |
+01:15:20.1 |
HIP 117491 |
18.92 |
| 2026-06-12 12:00 |
23:48:43.89 |
+01:17:36.3 |
HIP 117491 |
16.99 |
| 2026-06-13 00:00 |
23:49:02.41 |
+01:19:51.7 |
HIP 117491 |
16.52 |
| 2026-06-13 12:00 |
23:49:20.78 |
+01:22:06.1 |
HIP 117491 |
17.61 |
| 2026-06-14 00:00 |
23:49:38.99 |
+01:24:19.5 |
HIP 117491 |
19.96 |
| 2026-06-14 12:00 |
23:49:57.05 |
+01:26:32.0 |
HIP 117491 |
23.17 |
| 2026-06-15 00:00 |
23:50:14.94 |
+01:28:43.6 |
HIP 117491 |
26.91 |
| 2026-06-15 12:00 |
23:50:32.68 |
+01:30:54.1 |
HIP 117704 |
26.05 |
| 2026-06-16 00:00 |
23:50:50.26 |
+01:33:03.7 |
HIP 117704 |
21.86 |
| 2026-06-16 12:00 |
23:51:07.68 |
+01:35:12.4 |
HIP 117704 |
18.07 |
| 2026-06-17 00:00 |
23:51:24.94 |
+01:37:20.0 |
HIP 117704 |
14.94 |
| 2026-06-17 12:00 |
23:51:42.03 |
+01:39:26.6 |
HIP 117704 |
12.90 |
| 2026-06-18 00:00 |
23:51:58.96 |
+01:41:32.2 |
HIP 117704 |
12.45 |
| 2026-06-18 12:00 |
23:52:15.72 |
+01:43:36.9 |
HIP 117704 |
13.70 |
| 2026-06-19 00:00 |
23:52:32.32 |
+01:45:40.5 |
HIP 117805 |
15.50 |
| 2026-06-19 12:00 |
23:52:48.75 |
+01:47:43.0 |
HIP 117805 |
12.31 |
| 2026-06-20 00:00 |
23:53:05.02 |
+01:49:44.6 |
HIP 117805 |
10.25 |
| 2026-06-20 12:00 |
23:53:21.11 |
+01:51:45.1 |
HIP 117805 |
9.99 |
| 2026-06-21 00:00 |
23:53:37.04 |
+01:53:44.5 |
HIP 117805 |
11.59 |
| 2026-06-21 12:00 |
23:53:52.80 |
+01:55:42.9 |
HIP 117805 |
14.41 |
| 2026-06-22 00:00 |
23:54:08.38 |
+01:57:40.3 |
HIP 117774 |
17.69 |