C/2004 H6 (SWAN)
| Parameter |
Value |
| Designation |
C/2004 H6 (SWAN) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2004-05-12T16:30:22.481280Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:30:40Z |
| Obs used |
285 |
| NEO |
- |
| M1 |
10.300 |
| K1 |
25.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2004-07-30.0000000 |
| e |
1.00063094 |
| q (au) |
0.776283 |
| a (au) |
-1230.353854 |
| i (deg) |
107.663846 |
| Ω (om, deg) |
317.245375 |
| ω (w, deg) |
269.049126 |
| M (ma, deg) |
0.001788 |
Magnitude
Scatter + Global Linear
$$
M_a = (11.596 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
11.596 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2004-05-14 |
2004-09-08 |
+7.8785 |
-3.557 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
18:08:05.55 |
+41:45:49.7 |
HIP 88820 |
3.82 |
| 2026-02-03 12:00 |
18:08:08.22 |
+41:46:15.8 |
HIP 88820 |
4.48 |
| 2026-02-04 00:00 |
18:08:10.87 |
+41:46:42.2 |
HIP 88820 |
5.14 |
| 2026-02-04 12:00 |
18:08:13.51 |
+41:47:08.8 |
HIP 88820 |
5.80 |
| 2026-02-05 00:00 |
18:08:16.12 |
+41:47:35.7 |
HIP 88820 |
6.46 |
| 2026-02-05 12:00 |
18:08:18.71 |
+41:48:02.7 |
HIP 88820 |
7.12 |
| 2026-02-06 00:00 |
18:08:21.27 |
+41:48:30.1 |
HIP 88820 |
7.78 |
| 2026-02-06 12:00 |
18:08:23.82 |
+41:48:57.6 |
HIP 88820 |
8.44 |
| 2026-02-07 00:00 |
18:08:26.34 |
+41:49:25.4 |
HIP 88820 |
9.10 |
| 2026-02-07 12:00 |
18:08:28.85 |
+41:49:53.3 |
HIP 88820 |
9.76 |
| 2026-02-08 00:00 |
18:08:31.32 |
+41:50:21.6 |
HIP 88820 |
10.42 |
| 2026-02-08 12:00 |
18:08:33.78 |
+41:50:50.0 |
HIP 88820 |
11.08 |
| 2026-02-09 00:00 |
18:08:36.21 |
+41:51:18.6 |
HIP 88820 |
11.74 |
| 2026-02-09 12:00 |
18:08:38.62 |
+41:51:47.5 |
HIP 88820 |
12.39 |
| 2026-02-10 00:00 |
18:08:41.01 |
+41:52:16.6 |
HIP 88820 |
13.05 |
| 2026-02-10 12:00 |
18:08:43.37 |
+41:52:45.9 |
HIP 88820 |
13.71 |
| 2026-02-11 00:00 |
18:08:45.71 |
+41:53:15.4 |
HIP 88820 |
14.36 |
| 2026-02-11 12:00 |
18:08:48.02 |
+41:53:45.1 |
HIP 88820 |
15.02 |
| 2026-02-12 00:00 |
18:08:50.32 |
+41:54:15.0 |
HIP 88820 |
15.67 |
| 2026-02-12 12:00 |
18:08:52.58 |
+41:54:45.2 |
HIP 88820 |
16.32 |
| 2026-02-13 00:00 |
18:08:54.82 |
+41:55:15.5 |
HIP 88820 |
16.98 |
| 2026-02-13 12:00 |
18:08:57.04 |
+41:55:46.0 |
HIP 88820 |
17.63 |
| 2026-02-14 00:00 |
18:08:59.23 |
+41:56:16.8 |
HIP 88820 |
18.28 |
| 2026-02-14 12:00 |
18:09:01.40 |
+41:56:47.7 |
HIP 88820 |
18.93 |
| 2026-02-15 00:00 |
18:09:03.54 |
+41:57:18.8 |
HIP 88820 |
19.58 |
| 2026-02-15 12:00 |
18:09:05.66 |
+41:57:50.1 |
HIP 88832 |
19.90 |
| 2026-02-16 00:00 |
18:09:07.75 |
+41:58:21.7 |
HIP 88832 |
19.74 |
| 2026-02-16 12:00 |
18:09:09.81 |
+41:58:53.3 |
HIP 88832 |
19.59 |
| 2026-02-17 00:00 |
18:09:11.85 |
+41:59:25.2 |
HIP 88832 |
19.46 |
| 2026-02-17 12:00 |
18:09:13.86 |
+41:59:57.3 |
HIP 88832 |
19.35 |
| 2026-02-18 00:00 |
18:09:15.85 |
+42:00:29.5 |
HIP 88832 |
19.25 |
| 2026-02-18 12:00 |
18:09:17.81 |
+42:01:01.9 |
HIP 88832 |
19.16 |
| 2026-02-19 00:00 |
18:09:19.74 |
+42:01:34.5 |
HIP 88832 |
19.09 |
| 2026-02-19 12:00 |
18:09:21.65 |
+42:02:07.3 |
HIP 88832 |
19.04 |
| 2026-02-20 00:00 |
18:09:23.53 |
+42:02:40.2 |
HIP 88832 |
19.01 |
| 2026-02-20 12:00 |
18:09:25.38 |
+42:03:13.3 |
HIP 88832 |
18.99 |
| 2026-02-21 00:00 |
18:09:27.20 |
+42:03:46.6 |
HIP 88832 |
18.99 |
| 2026-02-21 12:00 |
18:09:29.00 |
+42:04:20.0 |
HIP 88832 |
19.00 |
| 2026-02-22 00:00 |
18:09:30.77 |
+42:04:53.6 |
HIP 88832 |
19.03 |
| 2026-02-22 12:00 |
18:09:32.51 |
+42:05:27.4 |
HIP 88832 |
19.08 |
| 2026-02-23 00:00 |
18:09:34.22 |
+42:06:01.3 |
HIP 88832 |
19.14 |
| 2026-02-23 12:00 |
18:09:35.91 |
+42:06:35.3 |
HIP 88832 |
19.22 |
| 2026-02-24 00:00 |
18:09:37.56 |
+42:07:09.5 |
HIP 88832 |
19.31 |