| Parameter |
Value |
| Designation |
C/2007 G1 (LINEAR) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2008-11-16T10:11:22.225920Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:31:06Z |
| Obs used |
2001 |
| NEO |
- |
| M1 |
10.800 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2008-01-11.0000000 |
| e |
1.00150564 |
| q (au) |
2.646214 |
| a (au) |
-1757.531288 |
| i (deg) |
88.358397 |
| Ω (om, deg) |
78.992256 |
| ω (w, deg) |
224.020457 |
| M (ma, deg) |
-0.004152 |
Magnitude
Scatter + Global Linear
$$
M_a = (12.690 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
12.690 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.732 |
| 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 |
| 2007-04-10 |
2007-09-17 |
+9.3628 |
-7.135 |
| 2007-09-17 |
2008-07-04 |
-5.1279 |
+3.059 |
| 2008-07-04 |
2008-10-24 |
+29.8517 |
-13.922 |
| 2009-01-03 |
2011-02-06 |
+1.0903 |
-0.233 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
05:14:40.21 |
+35:09:23.4 |
HIP 24464 |
12.66 |
| 2026-07-29 12:00 |
05:14:42.86 |
+35:09:36.4 |
HIP 24464 |
12.29 |
| 2026-07-30 00:00 |
05:14:45.49 |
+35:09:49.5 |
HIP 24464 |
11.95 |
| 2026-07-30 12:00 |
05:14:48.09 |
+35:10:02.5 |
HIP 24464 |
11.63 |
| 2026-07-31 00:00 |
05:14:50.67 |
+35:10:15.6 |
HIP 24464 |
11.32 |
| 2026-07-31 12:00 |
05:14:53.23 |
+35:10:28.8 |
HIP 24464 |
11.04 |
| 2026-08-01 00:00 |
05:14:55.76 |
+35:10:42.0 |
HIP 24464 |
10.77 |
| 2026-08-01 12:00 |
05:14:58.27 |
+35:10:55.2 |
HIP 24464 |
10.54 |
| 2026-08-02 00:00 |
05:15:00.76 |
+35:11:08.4 |
HIP 24464 |
10.32 |
| 2026-08-02 12:00 |
05:15:03.22 |
+35:11:21.7 |
HIP 24464 |
10.13 |
| 2026-08-03 00:00 |
05:15:05.66 |
+35:11:35.0 |
HIP 24464 |
9.97 |
| 2026-08-03 12:00 |
05:15:08.07 |
+35:11:48.4 |
HIP 24464 |
9.83 |
| 2026-08-04 00:00 |
05:15:10.46 |
+35:12:01.7 |
HIP 24464 |
9.71 |
| 2026-08-04 12:00 |
05:15:12.82 |
+35:12:15.1 |
HIP 24464 |
9.63 |
| 2026-08-05 00:00 |
05:15:15.16 |
+35:12:28.6 |
HIP 24464 |
9.57 |
| 2026-08-05 12:00 |
05:15:17.47 |
+35:12:42.0 |
HIP 24464 |
9.54 |
| 2026-08-06 00:00 |
05:15:19.76 |
+35:12:55.5 |
HIP 24464 |
9.53 |
| 2026-08-06 12:00 |
05:15:22.02 |
+35:13:09.0 |
HIP 24464 |
9.55 |
| 2026-08-07 00:00 |
05:15:24.25 |
+35:13:22.6 |
HIP 24464 |
9.59 |
| 2026-08-07 12:00 |
05:15:26.46 |
+35:13:36.1 |
HIP 24464 |
9.65 |
| 2026-08-08 00:00 |
05:15:28.64 |
+35:13:49.7 |
HIP 24464 |
9.74 |
| 2026-08-08 12:00 |
05:15:30.80 |
+35:14:03.3 |
HIP 24464 |
9.85 |
| 2026-08-09 00:00 |
05:15:32.93 |
+35:14:17.0 |
HIP 24464 |
9.98 |
| 2026-08-09 12:00 |
05:15:35.03 |
+35:14:30.7 |
HIP 24464 |
10.12 |
| 2026-08-10 00:00 |
05:15:37.11 |
+35:14:44.4 |
HIP 24464 |
10.28 |
| 2026-08-10 12:00 |
05:15:39.16 |
+35:14:58.1 |
HIP 24464 |
10.46 |
| 2026-08-11 00:00 |
05:15:41.18 |
+35:15:11.8 |
HIP 24464 |
10.65 |
| 2026-08-11 12:00 |
05:15:43.17 |
+35:15:25.6 |
HIP 24464 |
10.85 |
| 2026-08-12 00:00 |
05:15:45.13 |
+35:15:39.3 |
HIP 24464 |
11.06 |
| 2026-08-12 12:00 |
05:15:47.07 |
+35:15:53.1 |
HIP 24464 |
11.29 |
| 2026-08-13 00:00 |
05:15:48.98 |
+35:16:07.0 |
HIP 24464 |
11.52 |
| 2026-08-13 12:00 |
05:15:50.86 |
+35:16:20.8 |
HIP 24464 |
11.76 |
| 2026-08-14 00:00 |
05:15:52.71 |
+35:16:34.7 |
HIP 24464 |
12.00 |
| 2026-08-14 12:00 |
05:15:54.53 |
+35:16:48.5 |
HIP 24464 |
12.25 |
| 2026-08-15 00:00 |
05:15:56.33 |
+35:17:02.4 |
HIP 24464 |
12.51 |
| 2026-08-15 12:00 |
05:15:58.09 |
+35:17:16.3 |
HIP 24464 |
12.77 |
| 2026-08-16 00:00 |
05:15:59.83 |
+35:17:30.3 |
HIP 24464 |
13.03 |
| 2026-08-16 12:00 |
05:16:01.54 |
+35:17:44.2 |
HIP 24464 |
13.30 |
| 2026-08-17 00:00 |
05:16:03.21 |
+35:17:58.2 |
HIP 24464 |
13.56 |
| 2026-08-17 12:00 |
05:16:04.86 |
+35:18:12.1 |
HIP 24464 |
13.83 |
| 2026-08-18 00:00 |
05:16:06.48 |
+35:18:26.1 |
HIP 24464 |
14.10 |
| 2026-08-18 12:00 |
05:16:08.07 |
+35:18:40.1 |
HIP 24464 |
14.37 |
| 2026-08-19 00:00 |
05:16:09.62 |
+35:18:54.1 |
HIP 24464 |
14.64 |