289P/Blanpain
| Parameter |
Value |
| Designation |
289P/Blanpain |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2019-12-20T23:47:39.655680Z |
| Orbit solution date (soln_date, UTC) |
2025-05-23T12:29:45Z |
| Obs used |
356 |
| NEO |
Yes |
| M1 |
22.000 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-09-19.0000000 |
| e |
0.68514009 |
| q (au) |
0.958876 |
| a (au) |
3.045405 |
| i (deg) |
5.897388 |
| Ω (om, deg) |
68.924004 |
| ω (w, deg) |
9.849290 |
| M (ma, deg) |
342.754359 |
Magnitude
Scatter + Global Linear
$$
M_a = (18.699 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
18.699 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.501 |
| 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) |
| 2026-02-03 00:00 |
15:25:18.80 |
-15:18:09.0 |
HIP 75514 |
9.67 |
| 2026-02-03 12:00 |
15:25:34.88 |
-15:18:58.7 |
HIP 75514 |
7.77 |
| 2026-02-04 00:00 |
15:25:50.69 |
-15:19:47.3 |
HIP 75514 |
7.66 |
| 2026-02-04 12:00 |
15:26:06.24 |
-15:20:34.8 |
HIP 75514 |
9.30 |
| 2026-02-05 00:00 |
15:26:21.51 |
-15:21:21.1 |
HIP 75514 |
11.94 |
| 2026-02-05 12:00 |
15:26:36.51 |
-15:22:06.2 |
HIP 75514 |
15.01 |
| 2026-02-06 00:00 |
15:26:51.24 |
-15:22:50.2 |
HIP 75684 |
12.50 |
| 2026-02-06 12:00 |
15:27:05.69 |
-15:23:33.1 |
HIP 75684 |
8.95 |
| 2026-02-07 00:00 |
15:27:19.87 |
-15:24:14.8 |
HIP 75684 |
5.47 |
| 2026-02-07 12:00 |
15:27:33.76 |
-15:24:55.4 |
HIP 75684 |
2.08 |
| 2026-02-08 00:00 |
15:27:47.38 |
-15:25:34.8 |
HIP 75684 |
1.36 |
| 2026-02-08 12:00 |
15:28:00.71 |
-15:26:13.1 |
HIP 75684 |
4.60 |
| 2026-02-09 00:00 |
15:28:13.76 |
-15:26:50.3 |
HIP 75684 |
7.80 |
| 2026-02-09 12:00 |
15:28:26.53 |
-15:27:26.2 |
HIP 75684 |
10.93 |
| 2026-02-10 00:00 |
15:28:39.01 |
-15:28:01.1 |
HIP 75684 |
13.99 |
| 2026-02-10 12:00 |
15:28:51.20 |
-15:28:34.8 |
HIP 75851 |
11.58 |
| 2026-02-11 00:00 |
15:29:03.10 |
-15:29:07.4 |
HIP 75851 |
8.70 |
| 2026-02-11 12:00 |
15:29:14.71 |
-15:29:38.8 |
HIP 75851 |
5.92 |
| 2026-02-12 00:00 |
15:29:26.03 |
-15:30:09.0 |
HIP 75851 |
3.34 |
| 2026-02-12 12:00 |
15:29:37.05 |
-15:30:38.1 |
HIP 75851 |
1.62 |
| 2026-02-13 00:00 |
15:29:47.77 |
-15:31:06.1 |
HIP 75851 |
2.88 |
| 2026-02-13 12:00 |
15:29:58.20 |
-15:31:32.9 |
HIP 75851 |
5.20 |
| 2026-02-14 00:00 |
15:30:08.33 |
-15:31:58.6 |
HIP 75851 |
7.60 |
| 2026-02-14 12:00 |
15:30:18.16 |
-15:32:23.1 |
HIP 75905 |
9.05 |
| 2026-02-15 00:00 |
15:30:27.68 |
-15:32:46.5 |
HIP 75905 |
9.22 |
| 2026-02-15 12:00 |
15:30:36.90 |
-15:33:08.7 |
HIP 75905 |
9.93 |
| 2026-02-16 00:00 |
15:30:45.82 |
-15:33:29.7 |
HIP 75905 |
11.02 |
| 2026-02-16 12:00 |
15:30:54.42 |
-15:33:49.7 |
HIP 75905 |
12.35 |
| 2026-02-17 00:00 |
15:31:02.72 |
-15:34:08.5 |
HIP 76050 |
13.74 |
| 2026-02-17 12:00 |
15:31:10.72 |
-15:34:26.1 |
HIP 76050 |
11.96 |
| 2026-02-18 00:00 |
15:31:18.39 |
-15:34:42.6 |
HIP 76050 |
10.31 |
| 2026-02-18 12:00 |
15:31:25.76 |
-15:34:57.9 |
HIP 76050 |
8.81 |
| 2026-02-19 00:00 |
15:31:32.82 |
-15:35:12.1 |
HIP 76050 |
7.51 |
| 2026-02-19 12:00 |
15:31:39.56 |
-15:35:25.1 |
HIP 76050 |
6.46 |
| 2026-02-20 00:00 |
15:31:45.98 |
-15:35:37.1 |
HIP 76050 |
5.72 |
| 2026-02-20 12:00 |
15:31:52.09 |
-15:35:47.8 |
HIP 76050 |
5.37 |
| 2026-02-21 00:00 |
15:31:57.87 |
-15:35:57.4 |
HIP 76050 |
5.42 |
| 2026-02-21 12:00 |
15:32:03.34 |
-15:36:05.9 |
HIP 76050 |
5.79 |
| 2026-02-22 00:00 |
15:32:08.49 |
-15:36:13.3 |
HIP 76050 |
6.38 |
| 2026-02-22 12:00 |
15:32:13.32 |
-15:36:19.5 |
HIP 76050 |
7.10 |
| 2026-02-23 00:00 |
15:32:17.83 |
-15:36:24.6 |
HIP 76050 |
7.88 |
| 2026-02-23 12:00 |
15:32:22.01 |
-15:36:28.5 |
HIP 76050 |
8.66 |
| 2026-02-24 00:00 |
15:32:25.88 |
-15:36:31.3 |
HIP 76050 |
9.44 |