| Parameter |
Value |
| Designation |
C/2008 C1 (Chen-Gao) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-04-16T20:25:39.135360Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:16Z |
| Obs used |
754 |
| NEO |
- |
| M1 |
13.800 |
| K1 |
5.250 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-03-06.0000000 |
| e |
1.00000066 |
| q (au) |
1.262346 |
| a (au) |
-1909647.271764 |
| i (deg) |
61.784520 |
| Ω (om, deg) |
307.782377 |
| ω (w, deg) |
180.928392 |
| M (ma, deg) |
-0.000000 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.986 + 2.066\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.986 |
| n |
2.066 |
| 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 |
| 2008-01-30 |
2008-04-16 |
+12.3117 |
-3.108 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-06-01 00:00 |
20:23:38.44 |
-37:51:38.9 |
HIP 100584 |
21.77 |
| 2026-06-01 12:00 |
20:23:36.16 |
-37:51:55.2 |
HIP 100584 |
22.09 |
| 2026-06-02 00:00 |
20:23:33.85 |
-37:52:11.6 |
HIP 100433 |
22.05 |
| 2026-06-02 12:00 |
20:23:31.51 |
-37:52:28.0 |
HIP 100433 |
21.51 |
| 2026-06-03 00:00 |
20:23:29.15 |
-37:52:44.4 |
HIP 100433 |
20.97 |
| 2026-06-03 12:00 |
20:23:26.76 |
-37:53:00.7 |
HIP 100433 |
20.43 |
| 2026-06-04 00:00 |
20:23:24.34 |
-37:53:17.1 |
HIP 100433 |
19.88 |
| 2026-06-04 12:00 |
20:23:21.90 |
-37:53:33.4 |
HIP 100433 |
19.33 |
| 2026-06-05 00:00 |
20:23:19.43 |
-37:53:49.8 |
HIP 100433 |
18.78 |
| 2026-06-05 12:00 |
20:23:16.94 |
-37:54:06.1 |
HIP 100433 |
18.22 |
| 2026-06-06 00:00 |
20:23:14.42 |
-37:54:22.4 |
HIP 100433 |
17.66 |
| 2026-06-06 12:00 |
20:23:11.87 |
-37:54:38.6 |
HIP 100433 |
17.09 |
| 2026-06-07 00:00 |
20:23:09.30 |
-37:54:54.9 |
HIP 100433 |
16.52 |
| 2026-06-07 12:00 |
20:23:06.70 |
-37:55:11.1 |
HIP 100433 |
15.95 |
| 2026-06-08 00:00 |
20:23:04.08 |
-37:55:27.3 |
HIP 100433 |
15.38 |
| 2026-06-08 12:00 |
20:23:01.43 |
-37:55:43.5 |
HIP 100433 |
14.80 |
| 2026-06-09 00:00 |
20:22:58.76 |
-37:55:59.7 |
HIP 100433 |
14.22 |
| 2026-06-09 12:00 |
20:22:56.06 |
-37:56:15.8 |
HIP 100433 |
13.63 |
| 2026-06-10 00:00 |
20:22:53.34 |
-37:56:32.0 |
HIP 100433 |
13.05 |
| 2026-06-10 12:00 |
20:22:50.60 |
-37:56:48.0 |
HIP 100433 |
12.46 |
| 2026-06-11 00:00 |
20:22:47.83 |
-37:57:04.1 |
HIP 100433 |
11.87 |
| 2026-06-11 12:00 |
20:22:45.03 |
-37:57:20.1 |
HIP 100433 |
11.28 |
| 2026-06-12 00:00 |
20:22:42.22 |
-37:57:36.1 |
HIP 100433 |
10.69 |
| 2026-06-12 12:00 |
20:22:39.38 |
-37:57:52.1 |
HIP 100433 |
10.09 |
| 2026-06-13 00:00 |
20:22:36.51 |
-37:58:08.0 |
HIP 100433 |
9.50 |
| 2026-06-13 12:00 |
20:22:33.63 |
-37:58:23.9 |
HIP 100433 |
8.91 |
| 2026-06-14 00:00 |
20:22:30.72 |
-37:58:39.7 |
HIP 100433 |
8.33 |
| 2026-06-14 12:00 |
20:22:27.79 |
-37:58:55.5 |
HIP 100433 |
7.74 |
| 2026-06-15 00:00 |
20:22:24.83 |
-37:59:11.2 |
HIP 100433 |
7.17 |
| 2026-06-15 12:00 |
20:22:21.86 |
-37:59:27.0 |
HIP 100433 |
6.60 |
| 2026-06-16 00:00 |
20:22:18.86 |
-37:59:42.6 |
HIP 100433 |
6.05 |
| 2026-06-16 12:00 |
20:22:15.84 |
-37:59:58.2 |
HIP 100433 |
5.52 |
| 2026-06-17 00:00 |
20:22:12.80 |
-38:00:13.8 |
HIP 100433 |
5.01 |
| 2026-06-17 12:00 |
20:22:09.73 |
-38:00:29.3 |
HIP 100433 |
4.54 |
| 2026-06-18 00:00 |
20:22:06.65 |
-38:00:44.8 |
HIP 100433 |
4.12 |
| 2026-06-18 12:00 |
20:22:03.55 |
-38:01:00.2 |
HIP 100433 |
3.77 |
| 2026-06-19 00:00 |
20:22:00.42 |
-38:01:15.6 |
HIP 100433 |
3.52 |
| 2026-06-19 12:00 |
20:21:57.28 |
-38:01:30.9 |
HIP 100433 |
3.38 |
| 2026-06-20 00:00 |
20:21:54.11 |
-38:01:46.1 |
HIP 100433 |
3.37 |
| 2026-06-20 12:00 |
20:21:50.93 |
-38:02:01.3 |
HIP 100433 |
3.49 |
| 2026-06-21 00:00 |
20:21:47.73 |
-38:02:16.4 |
HIP 100433 |
3.75 |
| 2026-06-21 12:00 |
20:21:44.51 |
-38:02:31.5 |
HIP 100433 |
4.10 |
| 2026-06-22 00:00 |
20:21:41.27 |
-38:02:46.5 |
HIP 100433 |
4.53 |