| Parameter |
Value |
| Designation |
C/2013 G9 (Tenagra) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2015-01-14T14:39:54.149760Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:34Z |
| Obs used |
496 |
| NEO |
- |
| M1 |
6.500 |
| K1 |
10.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-06-28.0000000 |
| e |
1.00127209 |
| q (au) |
5.337621 |
| a (au) |
-4195.948868 |
| i (deg) |
146.233595 |
| Ω (om, deg) |
35.688660 |
| ω (w, deg) |
204.930440 |
| M (ma, deg) |
-0.000727 |
Magnitude
Scatter + Global Linear
$$
M_a = (1.736 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
1.736 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.953 |
| 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 |
| 2013-04-09 |
2015-01-12 |
+0.8615 |
-0.712 |
| 2015-01-17 |
2016-04-06 |
+15.2777 |
-11.324 |
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 |
04:14:29.68 |
+05:02:40.1 |
HIP 19818 |
10.88 |
| 2026-06-01 12:00 |
04:14:33.63 |
+05:02:53.3 |
HIP 19818 |
10.07 |
| 2026-06-02 00:00 |
04:14:37.59 |
+05:03:06.3 |
HIP 19818 |
9.29 |
| 2026-06-02 12:00 |
04:14:41.53 |
+05:03:19.1 |
HIP 19818 |
8.58 |
| 2026-06-03 00:00 |
04:14:45.48 |
+05:03:31.8 |
HIP 19818 |
7.92 |
| 2026-06-03 12:00 |
04:14:49.42 |
+05:03:44.2 |
HIP 19818 |
7.35 |
| 2026-06-04 00:00 |
04:14:53.35 |
+05:03:56.5 |
HIP 19818 |
6.88 |
| 2026-06-04 12:00 |
04:14:57.28 |
+05:04:08.6 |
HIP 19818 |
6.54 |
| 2026-06-05 00:00 |
04:15:01.20 |
+05:04:20.6 |
HIP 19818 |
6.34 |
| 2026-06-05 12:00 |
04:15:05.12 |
+05:04:32.4 |
HIP 19818 |
6.30 |
| 2026-06-06 00:00 |
04:15:09.04 |
+05:04:43.9 |
HIP 19818 |
6.41 |
| 2026-06-06 12:00 |
04:15:12.94 |
+05:04:55.4 |
HIP 19818 |
6.67 |
| 2026-06-07 00:00 |
04:15:16.84 |
+05:05:06.6 |
HIP 19818 |
7.07 |
| 2026-06-07 12:00 |
04:15:20.74 |
+05:05:17.6 |
HIP 19818 |
7.57 |
| 2026-06-08 00:00 |
04:15:24.62 |
+05:05:28.5 |
HIP 19818 |
8.17 |
| 2026-06-08 12:00 |
04:15:28.50 |
+05:05:39.2 |
HIP 19818 |
8.83 |
| 2026-06-09 00:00 |
04:15:32.37 |
+05:05:49.7 |
HIP 19818 |
9.55 |
| 2026-06-09 12:00 |
04:15:36.24 |
+05:06:00.0 |
HIP 19818 |
10.31 |
| 2026-06-10 00:00 |
04:15:40.09 |
+05:06:10.2 |
HIP 19818 |
11.11 |
| 2026-06-10 12:00 |
04:15:43.94 |
+05:06:20.1 |
HIP 19818 |
11.93 |
| 2026-06-11 00:00 |
04:15:47.78 |
+05:06:29.9 |
HIP 19818 |
12.77 |
| 2026-06-11 12:00 |
04:15:51.60 |
+05:06:39.5 |
HIP 19818 |
13.63 |
| 2026-06-12 00:00 |
04:15:55.42 |
+05:06:48.9 |
HIP 19818 |
14.50 |
| 2026-06-12 12:00 |
04:15:59.23 |
+05:06:58.1 |
HIP 19818 |
15.38 |
| 2026-06-13 00:00 |
04:16:03.03 |
+05:07:07.2 |
HIP 19818 |
16.26 |
| 2026-06-13 12:00 |
04:16:06.82 |
+05:07:16.0 |
HIP 19985 |
17.10 |
| 2026-06-14 00:00 |
04:16:10.60 |
+05:07:24.7 |
HIP 19985 |
16.27 |
| 2026-06-14 12:00 |
04:16:14.37 |
+05:07:33.1 |
HIP 19985 |
15.45 |
| 2026-06-15 00:00 |
04:16:18.13 |
+05:07:41.4 |
HIP 19985 |
14.65 |
| 2026-06-15 12:00 |
04:16:21.87 |
+05:07:49.5 |
HIP 19985 |
13.88 |
| 2026-06-16 00:00 |
04:16:25.61 |
+05:07:57.4 |
HIP 19985 |
13.12 |
| 2026-06-16 12:00 |
04:16:29.33 |
+05:08:05.2 |
HIP 19985 |
12.39 |
| 2026-06-17 00:00 |
04:16:33.04 |
+05:08:12.7 |
HIP 19985 |
11.69 |
| 2026-06-17 12:00 |
04:16:36.73 |
+05:08:20.0 |
HIP 19985 |
11.03 |
| 2026-06-18 00:00 |
04:16:40.42 |
+05:08:27.2 |
HIP 19985 |
10.41 |
| 2026-06-18 12:00 |
04:16:44.09 |
+05:08:34.2 |
HIP 19985 |
9.83 |
| 2026-06-19 00:00 |
04:16:47.74 |
+05:08:40.9 |
HIP 19985 |
9.31 |
| 2026-06-19 12:00 |
04:16:51.38 |
+05:08:47.5 |
HIP 19985 |
8.85 |
| 2026-06-20 00:00 |
04:16:55.01 |
+05:08:53.9 |
HIP 19985 |
8.47 |
| 2026-06-20 12:00 |
04:16:58.63 |
+05:09:00.1 |
HIP 19985 |
8.17 |
| 2026-06-21 00:00 |
04:17:02.22 |
+05:09:06.2 |
HIP 19985 |
7.96 |
| 2026-06-21 12:00 |
04:17:05.81 |
+05:09:12.0 |
HIP 19985 |
7.85 |
| 2026-06-22 00:00 |
04:17:09.38 |
+05:09:17.6 |
HIP 19985 |
7.83 |