| Parameter |
Value |
| Designation |
C/2006 U6 (Spacewatch) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-06-05T11:25:18.736320Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:01Z |
| Obs used |
552 |
| NEO |
- |
| M1 |
10.900 |
| K1 |
5.750 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-04-03.0000000 |
| e |
0.99870621 |
| q (au) |
2.498397 |
| a (au) |
1931.066467 |
| i (deg) |
84.878944 |
| Ω (om, deg) |
180.186317 |
| ω (w, deg) |
276.596980 |
| M (ma, deg) |
359.999263 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.450 + 2.405\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.450 |
| n |
2.405 |
| gf |
1.000 |
| gb |
-0.706 |
| k |
0.800 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2006-09-15 |
2007-09-14 |
+2.5893 |
-1.956 |
| 2007-09-14 |
2008-05-08 |
-3.2129 |
+1.746 |
| 2008-06-11 |
2010-06-04 |
-0.0917 |
-0.202 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
15:09:20.37 |
+54:55:33.4 |
HIP 74095 |
11.79 |
| 2026-05-12 12:00 |
15:09:15.18 |
+54:55:38.4 |
HIP 74095 |
11.46 |
| 2026-05-13 00:00 |
15:09:09.98 |
+54:55:42.9 |
HIP 74095 |
11.16 |
| 2026-05-13 12:00 |
15:09:04.79 |
+54:55:47.0 |
HIP 74095 |
10.90 |
| 2026-05-14 00:00 |
15:08:59.61 |
+54:55:50.8 |
HIP 74095 |
10.68 |
| 2026-05-14 12:00 |
15:08:54.42 |
+54:55:54.0 |
HIP 74095 |
10.50 |
| 2026-05-15 00:00 |
15:08:49.24 |
+54:55:56.9 |
HIP 74095 |
10.36 |
| 2026-05-15 12:00 |
15:08:44.07 |
+54:55:59.4 |
HIP 74095 |
10.27 |
| 2026-05-16 00:00 |
15:08:38.90 |
+54:56:01.4 |
HIP 74095 |
10.23 |
| 2026-05-16 12:00 |
15:08:33.73 |
+54:56:03.1 |
HIP 74095 |
10.24 |
| 2026-05-17 00:00 |
15:08:28.57 |
+54:56:04.3 |
HIP 74095 |
10.29 |
| 2026-05-17 12:00 |
15:08:23.42 |
+54:56:05.1 |
HIP 73994 |
9.75 |
| 2026-05-18 00:00 |
15:08:18.27 |
+54:56:05.5 |
HIP 73994 |
9.03 |
| 2026-05-18 12:00 |
15:08:13.13 |
+54:56:05.4 |
HIP 73994 |
8.32 |
| 2026-05-19 00:00 |
15:08:08.00 |
+54:56:05.0 |
HIP 73994 |
7.61 |
| 2026-05-19 12:00 |
15:08:02.87 |
+54:56:04.1 |
HIP 73994 |
6.91 |
| 2026-05-20 00:00 |
15:07:57.76 |
+54:56:02.9 |
HIP 73994 |
6.21 |
| 2026-05-20 12:00 |
15:07:52.65 |
+54:56:01.2 |
HIP 73994 |
5.52 |
| 2026-05-21 00:00 |
15:07:47.55 |
+54:55:59.1 |
HIP 73994 |
4.85 |
| 2026-05-21 12:00 |
15:07:42.47 |
+54:55:56.6 |
HIP 73994 |
4.19 |
| 2026-05-22 00:00 |
15:07:37.39 |
+54:55:53.7 |
HIP 73994 |
3.55 |
| 2026-05-22 12:00 |
15:07:32.32 |
+54:55:50.4 |
HIP 73994 |
2.96 |
| 2026-05-23 00:00 |
15:07:27.27 |
+54:55:46.7 |
HIP 73994 |
2.43 |
| 2026-05-23 12:00 |
15:07:22.23 |
+54:55:42.5 |
HIP 73994 |
2.03 |
| 2026-05-24 00:00 |
15:07:17.19 |
+54:55:38.0 |
HIP 73994 |
1.84 |
| 2026-05-24 12:00 |
15:07:12.18 |
+54:55:33.1 |
HIP 73994 |
1.91 |
| 2026-05-25 00:00 |
15:07:07.17 |
+54:55:27.7 |
HIP 73994 |
2.23 |
| 2026-05-25 12:00 |
15:07:02.18 |
+54:55:22.0 |
HIP 73994 |
2.70 |
| 2026-05-26 00:00 |
15:06:57.20 |
+54:55:15.9 |
HIP 73994 |
3.26 |
| 2026-05-26 12:00 |
15:06:52.24 |
+54:55:09.3 |
HIP 73994 |
3.87 |
| 2026-05-27 00:00 |
15:06:47.29 |
+54:55:02.4 |
HIP 73994 |
4.51 |
| 2026-05-27 12:00 |
15:06:42.35 |
+54:54:55.1 |
HIP 73994 |
5.17 |
| 2026-05-28 00:00 |
15:06:37.43 |
+54:54:47.3 |
HIP 73994 |
5.84 |
| 2026-05-28 12:00 |
15:06:32.53 |
+54:54:39.2 |
HIP 73994 |
6.51 |
| 2026-05-29 00:00 |
15:06:27.64 |
+54:54:30.7 |
HIP 73994 |
7.20 |
| 2026-05-29 12:00 |
15:06:22.76 |
+54:54:21.8 |
HIP 73994 |
7.88 |
| 2026-05-30 00:00 |
15:06:17.91 |
+54:54:12.5 |
HIP 73994 |
8.57 |
| 2026-05-30 12:00 |
15:06:13.07 |
+54:54:02.8 |
HIP 73994 |
9.26 |
| 2026-05-31 00:00 |
15:06:08.25 |
+54:53:52.7 |
HIP 73994 |
9.95 |
| 2026-05-31 12:00 |
15:06:03.45 |
+54:53:42.2 |
HIP 73994 |
10.64 |
| 2026-06-01 00:00 |
15:05:58.66 |
+54:53:31.4 |
HIP 73994 |
11.33 |
| 2026-06-01 12:00 |
15:05:53.90 |
+54:53:20.1 |
HIP 73994 |
12.02 |
| 2026-06-02 00:00 |
15:05:49.15 |
+54:53:08.5 |
HIP 73994 |
12.71 |