C/2011 A3 (Gibbs)
| Parameter |
Value |
| Designation |
C/2011 A3 (Gibbs) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2011-12-16T02:06:29.868480Z |
| Orbit solution date (soln_date, UTC) |
2021-04-16T12:05:53Z |
| Obs used |
1747 |
| NEO |
- |
| M1 |
9.900 |
| K1 |
8.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2011-07-07.0000000 |
| e |
0.99799388 |
| q (au) |
2.344841 |
| a (au) |
1168.845517 |
| i (deg) |
26.074353 |
| Ω (om, deg) |
124.895272 |
| ω (w, deg) |
141.161078 |
| M (ma, deg) |
359.996002 |
Magnitude
Scatter + Global Linear
$$
M_a = (7.606 + 4.476\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
7.606 |
| n |
4.476 |
| gf |
1.000 |
| gb |
-1.000 |
| 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 |
| 2011-01-15 |
2011-07-06 |
-1.9497 |
+1.190 |
| 2011-07-06 |
2011-10-24 |
+55.4815 |
-25.760 |
| 2012-03-05 |
2012-10-06 |
-2.7202 |
+0.970 |
| 2012-10-06 |
2013-10-06 |
-4.5442 |
+1.475 |
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 |
03:50:40.92 |
-05:09:01.1 |
HIP 17957 |
6.81 |
| 2026-02-03 12:00 |
03:50:40.12 |
-05:08:38.4 |
HIP 17957 |
6.41 |
| 2026-02-04 00:00 |
03:50:39.35 |
-05:08:15.6 |
HIP 17957 |
6.02 |
| 2026-02-04 12:00 |
03:50:38.62 |
-05:07:52.6 |
HIP 17957 |
5.65 |
| 2026-02-05 00:00 |
03:50:37.92 |
-05:07:29.4 |
HIP 17957 |
5.28 |
| 2026-02-05 12:00 |
03:50:37.25 |
-05:07:06.2 |
HIP 17957 |
4.94 |
| 2026-02-06 00:00 |
03:50:36.61 |
-05:06:42.8 |
HIP 17957 |
4.61 |
| 2026-02-06 12:00 |
03:50:36.01 |
-05:06:19.2 |
HIP 17957 |
4.30 |
| 2026-02-07 00:00 |
03:50:35.44 |
-05:05:55.6 |
HIP 17957 |
4.02 |
| 2026-02-07 12:00 |
03:50:34.91 |
-05:05:31.8 |
HIP 17957 |
3.78 |
| 2026-02-08 00:00 |
03:50:34.41 |
-05:05:07.9 |
HIP 17957 |
3.57 |
| 2026-02-08 12:00 |
03:50:33.94 |
-05:04:43.8 |
HIP 17957 |
3.41 |
| 2026-02-09 00:00 |
03:50:33.50 |
-05:04:19.7 |
HIP 17957 |
3.31 |
| 2026-02-09 12:00 |
03:50:33.10 |
-05:03:55.4 |
HIP 17957 |
3.26 |
| 2026-02-10 00:00 |
03:50:32.73 |
-05:03:31.0 |
HIP 17957 |
3.28 |
| 2026-02-10 12:00 |
03:50:32.39 |
-05:03:06.5 |
HIP 17957 |
3.36 |
| 2026-02-11 00:00 |
03:50:32.09 |
-05:02:41.8 |
HIP 17957 |
3.49 |
| 2026-02-11 12:00 |
03:50:31.82 |
-05:02:17.1 |
HIP 17957 |
3.68 |
| 2026-02-12 00:00 |
03:50:31.59 |
-05:01:52.2 |
HIP 17957 |
3.90 |
| 2026-02-12 12:00 |
03:50:31.39 |
-05:01:27.3 |
HIP 17957 |
4.17 |
| 2026-02-13 00:00 |
03:50:31.22 |
-05:01:02.2 |
HIP 17957 |
4.46 |
| 2026-02-13 12:00 |
03:50:31.08 |
-05:00:37.0 |
HIP 17957 |
4.78 |
| 2026-02-14 00:00 |
03:50:30.98 |
-05:00:11.7 |
HIP 17957 |
5.12 |
| 2026-02-14 12:00 |
03:50:30.91 |
-04:59:46.4 |
HIP 17957 |
5.48 |
| 2026-02-15 00:00 |
03:50:30.88 |
-04:59:20.9 |
HIP 17957 |
5.85 |
| 2026-02-15 12:00 |
03:50:30.88 |
-04:58:55.3 |
HIP 17957 |
6.23 |
| 2026-02-16 00:00 |
03:50:30.91 |
-04:58:29.6 |
HIP 17957 |
6.63 |
| 2026-02-16 12:00 |
03:50:30.98 |
-04:58:03.8 |
HIP 17957 |
7.03 |
| 2026-02-17 00:00 |
03:50:31.07 |
-04:57:38.0 |
HIP 17957 |
7.44 |
| 2026-02-17 12:00 |
03:50:31.21 |
-04:57:12.0 |
HIP 17957 |
7.85 |
| 2026-02-18 00:00 |
03:50:31.37 |
-04:56:46.0 |
HIP 17957 |
8.28 |
| 2026-02-18 12:00 |
03:50:31.57 |
-04:56:19.9 |
HIP 17957 |
8.70 |
| 2026-02-19 00:00 |
03:50:31.81 |
-04:55:53.7 |
HIP 17957 |
9.13 |
| 2026-02-19 12:00 |
03:50:32.07 |
-04:55:27.4 |
HIP 17957 |
9.57 |
| 2026-02-20 00:00 |
03:50:32.37 |
-04:55:01.0 |
HIP 17957 |
10.01 |
| 2026-02-20 12:00 |
03:50:32.70 |
-04:54:34.6 |
HIP 17957 |
10.46 |
| 2026-02-21 00:00 |
03:50:33.07 |
-04:54:08.1 |
HIP 17957 |
10.91 |
| 2026-02-21 12:00 |
03:50:33.47 |
-04:53:41.5 |
HIP 17957 |
11.36 |
| 2026-02-22 00:00 |
03:50:33.90 |
-04:53:14.8 |
HIP 17957 |
11.82 |
| 2026-02-22 12:00 |
03:50:34.36 |
-04:52:48.1 |
HIP 17957 |
12.28 |
| 2026-02-23 00:00 |
03:50:34.86 |
-04:52:21.3 |
HIP 17957 |
12.74 |
| 2026-02-23 12:00 |
03:50:35.39 |
-04:51:54.5 |
HIP 17957 |
13.21 |
| 2026-02-24 00:00 |
03:50:35.95 |
-04:51:27.6 |
HIP 17957 |
13.68 |