| Parameter |
Value |
| Designation |
414P/STEREO |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2021-01-25T07:45:13.775040Z |
| Orbit solution date (soln_date, UTC) |
2026-01-07T20:33:37Z |
| Obs used |
300 |
| NEO |
Yes |
| M1 |
20.500 |
| K1 |
39.500 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2021-01-04T02:11:29.184000Z |
| Discovery magnitude (MPC) |
19.10 R |
| Discovery observatory (MPC) |
I41 · Palomar Mountain–ZTF |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2022-11-22.0000000 |
| e |
0.81171958 |
| q (au) |
0.525961 |
| a (au) |
2.793500 |
| i (deg) |
23.392649 |
| Ω (om, deg) |
257.794317 |
| ω (w, deg) |
210.708294 |
| M (ma, deg) |
140.522045 |
Magnitude
Scatter + Global Linear
$$
M_a = (19.811 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
19.811 |
| n |
6.000 |
| gf |
1.000 |
| 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 |
| 2025-07-28 |
2025-09-23 |
+7.7015 |
+0.046 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
16:39:23.32 |
-18:53:13.4 |
HIP 81486 |
12.07 |
| 2026-09-20 12:00 |
16:39:42.01 |
-18:53:27.1 |
HIP 81486 |
16.39 |
| 2026-09-21 00:00 |
16:40:00.85 |
-18:53:41.0 |
HIP 81486 |
20.79 |
| 2026-09-21 12:00 |
16:40:19.85 |
-18:53:55.1 |
HIP 81758 |
23.24 |
| 2026-09-22 00:00 |
16:40:38.99 |
-18:54:09.5 |
HIP 81758 |
18.72 |
| 2026-09-22 12:00 |
16:40:58.29 |
-18:54:24.1 |
HIP 81758 |
14.16 |
| 2026-09-23 00:00 |
16:41:17.73 |
-18:54:38.9 |
HIP 81758 |
9.57 |
| 2026-09-23 12:00 |
16:41:37.32 |
-18:54:53.9 |
HIP 81758 |
4.99 |
| 2026-09-24 00:00 |
16:41:57.05 |
-18:55:09.0 |
HIP 81758 |
1.12 |
| 2026-09-24 12:00 |
16:42:16.93 |
-18:55:24.4 |
HIP 81758 |
4.64 |
| 2026-09-25 00:00 |
16:42:36.95 |
-18:55:39.9 |
HIP 81758 |
9.32 |
| 2026-09-25 12:00 |
16:42:57.11 |
-18:55:55.6 |
HIP 81758 |
14.07 |
| 2026-09-26 00:00 |
16:43:17.41 |
-18:56:11.5 |
HIP 81758 |
18.87 |
| 2026-09-26 12:00 |
16:43:37.84 |
-18:56:27.5 |
HIP 81758 |
23.70 |
| 2026-09-27 00:00 |
16:43:58.42 |
-18:56:43.7 |
HIP 81931 |
24.30 |
| 2026-09-27 12:00 |
16:44:19.13 |
-18:57:00.0 |
HIP 82038 |
20.19 |
| 2026-09-28 00:00 |
16:44:39.97 |
-18:57:16.4 |
HIP 82038 |
16.14 |
| 2026-09-28 12:00 |
16:45:00.95 |
-18:57:33.0 |
HIP 82038 |
12.71 |
| 2026-09-29 00:00 |
16:45:22.06 |
-18:57:49.7 |
HIP 82038 |
10.56 |
| 2026-09-29 12:00 |
16:45:43.30 |
-18:58:06.5 |
HIP 82038 |
10.57 |
| 2026-09-30 00:00 |
16:46:04.67 |
-18:58:23.4 |
HIP 82038 |
12.77 |
| 2026-09-30 12:00 |
16:46:26.17 |
-18:58:40.4 |
HIP 82128 |
11.78 |
| 2026-10-01 00:00 |
16:46:47.80 |
-18:58:57.4 |
HIP 82128 |
11.78 |
| 2026-10-01 12:00 |
16:47:09.55 |
-18:59:14.6 |
HIP 82128 |
13.85 |
| 2026-10-02 00:00 |
16:47:31.43 |
-18:59:31.8 |
HIP 82128 |
17.28 |
| 2026-10-02 12:00 |
16:47:53.43 |
-18:59:49.1 |
HIP 82265 |
19.67 |
| 2026-10-03 00:00 |
16:48:15.56 |
-19:00:06.5 |
HIP 82265 |
17.56 |
| 2026-10-03 12:00 |
16:48:37.81 |
-19:00:23.9 |
HIP 82265 |
16.87 |
| 2026-10-04 00:00 |
16:49:00.18 |
-19:00:41.4 |
HIP 82265 |
17.79 |
| 2026-10-04 12:00 |
16:49:22.67 |
-19:00:58.9 |
HIP 82265 |
20.13 |
| 2026-10-05 00:00 |
16:49:45.28 |
-19:01:16.5 |
HIP 82433 |
15.01 |
| 2026-10-05 12:00 |
16:50:08.01 |
-19:01:34.0 |
HIP 82433 |
9.65 |
| 2026-10-06 00:00 |
16:50:30.86 |
-19:01:51.6 |
HIP 82433 |
4.31 |
| 2026-10-06 12:00 |
16:50:53.82 |
-19:02:09.2 |
HIP 82433 |
1.59 |
| 2026-10-07 00:00 |
16:51:16.90 |
-19:02:26.9 |
HIP 82433 |
6.78 |
| 2026-10-07 12:00 |
16:51:40.09 |
-19:02:44.5 |
HIP 82465 |
11.01 |
| 2026-10-08 00:00 |
16:52:03.39 |
-19:03:02.1 |
HIP 82465 |
14.97 |
| 2026-10-08 12:00 |
16:52:26.81 |
-19:03:19.7 |
HIP 82547 |
18.14 |
| 2026-10-09 00:00 |
16:52:50.33 |
-19:03:37.2 |
HIP 82547 |
19.12 |
| 2026-10-09 12:00 |
16:53:13.97 |
-19:03:54.8 |
HIP 82547 |
21.56 |
| 2026-10-10 00:00 |
16:53:37.71 |
-19:04:12.3 |
HIP 82704 |
20.28 |
| 2026-10-10 12:00 |
16:54:01.56 |
-19:04:29.7 |
HIP 82704 |
17.97 |
| 2026-10-11 00:00 |
16:54:25.52 |
-19:04:47.2 |
HIP 82787 |
15.20 |