| Parameter |
Value |
| Designation |
C/2014 C2 (STEREO) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2014-02-18T05:53:19.752000Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:32:48Z |
| Obs used |
297 |
| NEO |
- |
| M1 |
14.400 |
| K1 |
9.300 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2014-03-08.0000000 |
| e |
1.00000000 |
| q (au) |
0.512340 |
| a (au) |
- |
| i (deg) |
135.502163 |
| Ω (om, deg) |
283.347106 |
| ω (w, deg) |
56.075501 |
| M (ma, deg) |
- |
Magnitude
Scatter + Global Linear
$$
M_a = (15.851 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.851 |
| n |
6.000 |
| gf |
0.800 |
| gb |
-1.000 |
| 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 |
| 2014-01-31 |
2014-02-16 |
-109.8474 |
-24.213 |
| 2014-02-19 |
2014-04-21 |
-4.4994 |
+2.124 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-03-26 00:00 |
04:47:44.91 |
-04:42:20.5 |
HIP 22206 |
18.93 |
| 2026-03-26 12:00 |
04:47:46.28 |
-04:41:54.0 |
HIP 22206 |
19.12 |
| 2026-03-27 00:00 |
04:47:47.68 |
-04:41:27.5 |
HIP 22206 |
19.33 |
| 2026-03-27 12:00 |
04:47:49.10 |
-04:41:01.1 |
HIP 22206 |
19.56 |
| 2026-03-28 00:00 |
04:47:50.56 |
-04:40:34.7 |
HIP 22206 |
19.81 |
| 2026-03-28 12:00 |
04:47:52.05 |
-04:40:08.4 |
HIP 22206 |
20.09 |
| 2026-03-29 00:00 |
04:47:53.57 |
-04:39:42.2 |
HIP 22206 |
20.38 |
| 2026-03-29 12:00 |
04:47:55.12 |
-04:39:16.0 |
HIP 22206 |
20.69 |
| 2026-03-30 00:00 |
04:47:56.69 |
-04:38:49.9 |
HIP 22206 |
21.02 |
| 2026-03-30 12:00 |
04:47:58.30 |
-04:38:23.9 |
HIP 22206 |
21.38 |
| 2026-03-31 00:00 |
04:47:59.94 |
-04:37:57.9 |
HIP 22206 |
21.74 |
| 2026-03-31 12:00 |
04:48:01.61 |
-04:37:32.0 |
HIP 22206 |
22.13 |
| 2026-04-01 00:00 |
04:48:03.30 |
-04:37:06.1 |
HIP 22206 |
22.53 |
| 2026-04-01 12:00 |
04:48:05.03 |
-04:36:40.4 |
HIP 22206 |
22.95 |
| 2026-04-02 00:00 |
04:48:06.79 |
-04:36:14.7 |
HIP 22206 |
23.39 |
| 2026-04-02 12:00 |
04:48:08.57 |
-04:35:49.1 |
HIP 22206 |
23.84 |
| 2026-04-03 00:00 |
04:48:10.38 |
-04:35:23.6 |
HIP 22206 |
24.30 |
| 2026-04-03 12:00 |
04:48:12.22 |
-04:34:58.1 |
HIP 22206 |
24.78 |
| 2026-04-04 00:00 |
04:48:14.09 |
-04:34:32.7 |
HIP 22206 |
25.27 |
| 2026-04-04 12:00 |
04:48:15.99 |
-04:34:07.5 |
HIP 22206 |
25.77 |
| 2026-04-05 00:00 |
04:48:17.92 |
-04:33:42.2 |
HIP 22206 |
26.29 |
| 2026-04-05 12:00 |
04:48:19.87 |
-04:33:17.1 |
HIP 22206 |
26.82 |
| 2026-04-06 00:00 |
04:48:21.85 |
-04:32:52.1 |
HIP 22206 |
27.36 |
| 2026-04-06 12:00 |
04:48:23.86 |
-04:32:27.2 |
HIP 22206 |
27.91 |
| 2026-04-07 00:00 |
04:48:25.89 |
-04:32:02.3 |
HIP 22206 |
28.47 |
| 2026-04-07 12:00 |
04:48:27.96 |
-04:31:37.6 |
HIP 22206 |
29.04 |
| 2026-04-08 00:00 |
04:48:30.05 |
-04:31:12.9 |
HIP 22206 |
29.62 |
| 2026-04-08 12:00 |
04:48:32.17 |
-04:30:48.4 |
HIP 22396 |
30.20 |
| 2026-04-09 00:00 |
04:48:34.31 |
-04:30:23.9 |
HIP 22396 |
30.40 |
| 2026-04-09 12:00 |
04:48:36.48 |
-04:29:59.5 |
HIP 22396 |
30.62 |
| 2026-04-10 00:00 |
04:48:38.68 |
-04:29:35.3 |
HIP 22396 |
30.85 |
| 2026-04-10 12:00 |
04:48:40.90 |
-04:29:11.1 |
HIP 22396 |
31.09 |
| 2026-04-11 00:00 |
04:48:43.15 |
-04:28:47.1 |
HIP 22396 |
31.33 |
| 2026-04-11 12:00 |
04:48:45.42 |
-04:28:23.1 |
HIP 22396 |
31.59 |
| 2026-04-12 00:00 |
04:48:47.73 |
-04:27:59.3 |
HIP 22396 |
31.86 |
| 2026-04-12 12:00 |
04:48:50.05 |
-04:27:35.6 |
HIP 22396 |
32.13 |
| 2026-04-13 00:00 |
04:48:52.40 |
-04:27:12.0 |
HIP 22396 |
32.42 |
| 2026-04-13 12:00 |
04:48:54.78 |
-04:26:48.5 |
HIP 22511 |
32.26 |
| 2026-04-14 00:00 |
04:48:57.18 |
-04:26:25.1 |
HIP 22511 |
31.54 |
| 2026-04-14 12:00 |
04:48:59.61 |
-04:26:01.8 |
HIP 22511 |
30.83 |
| 2026-04-15 00:00 |
04:49:02.06 |
-04:25:38.7 |
HIP 22511 |
30.11 |
| 2026-04-15 12:00 |
04:49:04.53 |
-04:25:15.6 |
HIP 22511 |
29.39 |
| 2026-04-16 00:00 |
04:49:07.03 |
-04:24:52.7 |
HIP 22511 |
28.66 |