C/2007 G1 (LINEAR)
| 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 |
0.988 |
| 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 |
+9.3624 |
-7.134 |
| 2007-09-17 |
2008-07-04 |
-5.1278 |
+3.059 |
| 2008-07-04 |
2008-10-24 |
+29.8486 |
-13.920 |
| 2009-01-03 |
2011-02-06 |
+1.0900 |
-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) |
| 2026-02-03 00:00 |
05:02:27.82 |
+35:02:40.3 |
HIP 23337 |
35.90 |
| 2026-02-03 12:00 |
05:02:25.50 |
+35:02:31.6 |
HIP 23337 |
35.56 |
| 2026-02-04 00:00 |
05:02:23.22 |
+35:02:22.9 |
HIP 23337 |
35.23 |
| 2026-02-04 12:00 |
05:02:20.98 |
+35:02:14.2 |
HIP 23337 |
34.90 |
| 2026-02-05 00:00 |
05:02:18.76 |
+35:02:05.5 |
HIP 23337 |
34.59 |
| 2026-02-05 12:00 |
05:02:16.58 |
+35:01:56.8 |
HIP 23337 |
34.27 |
| 2026-02-06 00:00 |
05:02:14.43 |
+35:01:48.1 |
HIP 23337 |
33.97 |
| 2026-02-06 12:00 |
05:02:12.32 |
+35:01:39.3 |
HIP 23337 |
33.67 |
| 2026-02-07 00:00 |
05:02:10.23 |
+35:01:30.6 |
HIP 23337 |
33.38 |
| 2026-02-07 12:00 |
05:02:08.18 |
+35:01:21.8 |
HIP 23337 |
33.09 |
| 2026-02-08 00:00 |
05:02:06.17 |
+35:01:13.1 |
HIP 23337 |
32.81 |
| 2026-02-08 12:00 |
05:02:04.19 |
+35:01:04.3 |
HIP 23337 |
32.53 |
| 2026-02-09 00:00 |
05:02:02.24 |
+35:00:55.6 |
HIP 23337 |
32.26 |
| 2026-02-09 12:00 |
05:02:00.32 |
+35:00:46.8 |
HIP 23337 |
31.99 |
| 2026-02-10 00:00 |
05:01:58.44 |
+35:00:38.0 |
HIP 23337 |
31.73 |
| 2026-02-10 12:00 |
05:01:56.60 |
+35:00:29.3 |
HIP 23337 |
31.48 |
| 2026-02-11 00:00 |
05:01:54.78 |
+35:00:20.5 |
HIP 23337 |
31.23 |
| 2026-02-11 12:00 |
05:01:53.00 |
+35:00:11.8 |
HIP 23337 |
30.99 |
| 2026-02-12 00:00 |
05:01:51.26 |
+35:00:03.0 |
HIP 23337 |
30.75 |
| 2026-02-12 12:00 |
05:01:49.55 |
+34:59:54.3 |
HIP 23337 |
30.52 |
| 2026-02-13 00:00 |
05:01:47.88 |
+34:59:45.5 |
HIP 23337 |
30.29 |
| 2026-02-13 12:00 |
05:01:46.24 |
+34:59:36.8 |
HIP 23337 |
30.06 |
| 2026-02-14 00:00 |
05:01:44.63 |
+34:59:28.1 |
HIP 23337 |
29.84 |
| 2026-02-14 12:00 |
05:01:43.06 |
+34:59:19.4 |
HIP 23337 |
29.63 |
| 2026-02-15 00:00 |
05:01:41.53 |
+34:59:10.6 |
HIP 23337 |
29.42 |
| 2026-02-15 12:00 |
05:01:40.03 |
+34:59:01.9 |
HIP 23337 |
29.21 |
| 2026-02-16 00:00 |
05:01:38.57 |
+34:58:53.3 |
HIP 23337 |
29.01 |
| 2026-02-16 12:00 |
05:01:37.14 |
+34:58:44.6 |
HIP 23337 |
28.81 |
| 2026-02-17 00:00 |
05:01:35.74 |
+34:58:35.9 |
HIP 23337 |
28.62 |
| 2026-02-17 12:00 |
05:01:34.39 |
+34:58:27.3 |
HIP 23337 |
28.43 |
| 2026-02-18 00:00 |
05:01:33.06 |
+34:58:18.7 |
HIP 23337 |
28.24 |
| 2026-02-18 12:00 |
05:01:31.78 |
+34:58:10.1 |
HIP 23337 |
28.06 |
| 2026-02-19 00:00 |
05:01:30.53 |
+34:58:01.5 |
HIP 23337 |
27.88 |
| 2026-02-19 12:00 |
05:01:29.31 |
+34:57:52.9 |
HIP 23337 |
27.70 |
| 2026-02-20 00:00 |
05:01:28.13 |
+34:57:44.4 |
HIP 23337 |
27.53 |
| 2026-02-20 12:00 |
05:01:26.99 |
+34:57:35.8 |
HIP 23337 |
27.36 |
| 2026-02-21 00:00 |
05:01:25.88 |
+34:57:27.3 |
HIP 23337 |
27.19 |
| 2026-02-21 12:00 |
05:01:24.81 |
+34:57:18.9 |
HIP 23337 |
27.02 |
| 2026-02-22 00:00 |
05:01:23.78 |
+34:57:10.4 |
HIP 23337 |
26.86 |
| 2026-02-22 12:00 |
05:01:22.78 |
+34:57:02.0 |
HIP 23337 |
26.70 |
| 2026-02-23 00:00 |
05:01:21.82 |
+34:56:53.6 |
HIP 23337 |
26.55 |
| 2026-02-23 12:00 |
05:01:20.89 |
+34:56:45.2 |
HIP 23337 |
26.39 |
| 2026-02-24 00:00 |
05:01:20.00 |
+34:56:36.9 |
HIP 23337 |
26.24 |