C/2009 U5 (Grauer)
| Parameter |
Value |
| Designation |
C/2009 U5 (Grauer) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2010-06-22T11:50:14.052480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:37Z |
| Obs used |
182 |
| NEO |
- |
| M1 |
11.800 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2010-02-02.0000000 |
| e |
0.99942402 |
| q (au) |
6.094240 |
| a (au) |
10580.667509 |
| i (deg) |
25.472676 |
| Ω (om, deg) |
121.174091 |
| ω (w, deg) |
23.813513 |
| M (ma, deg) |
359.999873 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.379 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.379 |
| n |
2.000 |
| 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) |
| 2026-02-03 00:00 |
18:20:45.21 |
-11:26:11.1 |
HIP 89828 |
15.78 |
| 2026-02-03 12:00 |
18:20:48.69 |
-11:26:04.3 |
HIP 89828 |
16.43 |
| 2026-02-04 00:00 |
18:20:52.14 |
-11:25:57.4 |
HIP 89828 |
17.09 |
| 2026-02-04 12:00 |
18:20:55.58 |
-11:25:50.5 |
HIP 89828 |
17.77 |
| 2026-02-05 00:00 |
18:20:58.99 |
-11:25:43.4 |
HIP 89828 |
18.45 |
| 2026-02-05 12:00 |
18:21:02.38 |
-11:25:36.3 |
HIP 89828 |
19.14 |
| 2026-02-06 00:00 |
18:21:05.75 |
-11:25:29.1 |
HIP 89828 |
19.84 |
| 2026-02-06 12:00 |
18:21:09.10 |
-11:25:21.9 |
HIP 89828 |
20.54 |
| 2026-02-07 00:00 |
18:21:12.42 |
-11:25:14.5 |
HIP 89828 |
21.24 |
| 2026-02-07 12:00 |
18:21:15.73 |
-11:25:07.2 |
HIP 89828 |
21.95 |
| 2026-02-08 00:00 |
18:21:19.01 |
-11:24:59.7 |
HIP 89828 |
22.66 |
| 2026-02-08 12:00 |
18:21:22.26 |
-11:24:52.2 |
HIP 89828 |
23.37 |
| 2026-02-09 00:00 |
18:21:25.50 |
-11:24:44.6 |
HIP 89828 |
24.08 |
| 2026-02-09 12:00 |
18:21:28.71 |
-11:24:36.9 |
HIP 89828 |
24.79 |
| 2026-02-10 00:00 |
18:21:31.89 |
-11:24:29.2 |
HIP 89828 |
25.50 |
| 2026-02-10 12:00 |
18:21:35.06 |
-11:24:21.4 |
HIP 89828 |
26.21 |
| 2026-02-11 00:00 |
18:21:38.20 |
-11:24:13.6 |
HIP 89828 |
26.92 |
| 2026-02-11 12:00 |
18:21:41.31 |
-11:24:05.6 |
HIP 89828 |
27.62 |
| 2026-02-12 00:00 |
18:21:44.40 |
-11:23:57.7 |
HIP 89828 |
28.33 |
| 2026-02-12 12:00 |
18:21:47.47 |
-11:23:49.6 |
HIP 89828 |
29.03 |
| 2026-02-13 00:00 |
18:21:50.51 |
-11:23:41.5 |
HIP 89828 |
29.72 |
| 2026-02-13 12:00 |
18:21:53.52 |
-11:23:33.4 |
HIP 89828 |
30.42 |
| 2026-02-14 00:00 |
18:21:56.51 |
-11:23:25.2 |
HIP 89828 |
31.11 |
| 2026-02-14 12:00 |
18:21:59.47 |
-11:23:16.9 |
HIP 89828 |
31.79 |
| 2026-02-15 00:00 |
18:22:02.41 |
-11:23:08.5 |
HIP 90004 |
32.36 |
| 2026-02-15 12:00 |
18:22:05.33 |
-11:23:00.2 |
HIP 90004 |
32.57 |
| 2026-02-16 00:00 |
18:22:08.21 |
-11:22:51.7 |
HIP 90004 |
32.80 |
| 2026-02-16 12:00 |
18:22:11.07 |
-11:22:43.2 |
HIP 90004 |
33.04 |
| 2026-02-17 00:00 |
18:22:13.91 |
-11:22:34.7 |
HIP 90004 |
33.30 |
| 2026-02-17 12:00 |
18:22:16.71 |
-11:22:26.1 |
HIP 90004 |
33.57 |
| 2026-02-18 00:00 |
18:22:19.49 |
-11:22:17.4 |
HIP 90004 |
33.85 |
| 2026-02-18 12:00 |
18:22:22.24 |
-11:22:08.7 |
HIP 90004 |
34.14 |
| 2026-02-19 00:00 |
18:22:24.97 |
-11:22:00.0 |
HIP 90004 |
34.45 |
| 2026-02-19 12:00 |
18:22:27.67 |
-11:21:51.1 |
HIP 90244 |
34.44 |
| 2026-02-20 00:00 |
18:22:30.34 |
-11:21:42.3 |
HIP 90244 |
33.79 |
| 2026-02-20 12:00 |
18:22:32.98 |
-11:21:33.4 |
HIP 90244 |
33.14 |
| 2026-02-21 00:00 |
18:22:35.60 |
-11:21:24.4 |
HIP 90244 |
32.50 |
| 2026-02-21 12:00 |
18:22:38.18 |
-11:21:15.4 |
HIP 90244 |
31.87 |
| 2026-02-22 00:00 |
18:22:40.74 |
-11:21:06.4 |
HIP 90244 |
31.25 |
| 2026-02-22 12:00 |
18:22:43.27 |
-11:20:57.3 |
HIP 90244 |
30.63 |
| 2026-02-23 00:00 |
18:22:45.77 |
-11:20:48.2 |
HIP 90244 |
30.03 |
| 2026-02-23 12:00 |
18:22:48.24 |
-11:20:39.0 |
HIP 90244 |
29.43 |
| 2026-02-24 00:00 |
18:22:50.68 |
-11:20:29.8 |
HIP 90244 |
28.83 |