| 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 |
-0.999 |
| 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) |
| 2026-05-12 00:00 |
17:47:37.57 |
-24:46:43.4 |
HIP 87093 |
24.65 |
| 2026-05-12 12:00 |
17:47:01.05 |
-24:44:50.3 |
HIP 87093 |
28.21 |
| 2026-05-13 00:00 |
17:46:24.24 |
-24:42:56.3 |
HIP 86866 |
20.46 |
| 2026-05-13 12:00 |
17:45:47.13 |
-24:41:01.5 |
HIP 86866 |
11.95 |
| 2026-05-14 00:00 |
17:45:09.73 |
-24:39:05.8 |
HIP 86866 |
3.96 |
| 2026-05-14 12:00 |
17:44:32.05 |
-24:37:09.3 |
HIP 86866 |
6.42 |
| 2026-05-15 00:00 |
17:43:54.10 |
-24:35:11.9 |
HIP 86705 |
12.73 |
| 2026-05-15 12:00 |
17:43:15.87 |
-24:33:13.6 |
HIP 86705 |
3.92 |
| 2026-05-16 00:00 |
17:42:37.39 |
-24:31:14.5 |
HIP 86705 |
5.29 |
| 2026-05-16 12:00 |
17:41:58.66 |
-24:29:14.5 |
HIP 86673 |
13.84 |
| 2026-05-17 00:00 |
17:41:19.68 |
-24:27:13.6 |
HIP 86673 |
18.85 |
| 2026-05-17 12:00 |
17:40:40.47 |
-24:25:11.9 |
HIP 86533 |
25.39 |
| 2026-05-18 00:00 |
17:40:01.02 |
-24:23:09.3 |
HIP 86533 |
26.70 |
| 2026-05-18 12:00 |
17:39:21.36 |
-24:21:05.9 |
HIP 86533 |
30.88 |
| 2026-05-19 00:00 |
17:38:41.49 |
-24:19:01.6 |
HIP 86226 |
25.54 |
| 2026-05-19 12:00 |
17:38:01.41 |
-24:16:56.5 |
HIP 86226 |
21.32 |
| 2026-05-20 00:00 |
17:37:21.15 |
-24:14:50.5 |
HIP 86226 |
20.79 |
| 2026-05-20 12:00 |
17:36:40.69 |
-24:12:43.6 |
HIP 86226 |
24.25 |
| 2026-05-21 00:00 |
17:36:00.06 |
-24:10:36.0 |
HIP 86086 |
27.73 |
| 2026-05-21 12:00 |
17:35:19.26 |
-24:08:27.5 |
HIP 85920 |
25.48 |
| 2026-05-22 00:00 |
17:34:38.30 |
-24:06:18.1 |
HIP 85920 |
15.92 |
| 2026-05-22 12:00 |
17:33:57.19 |
-24:04:08.0 |
HIP 85920 |
6.42 |
| 2026-05-23 00:00 |
17:33:15.94 |
-24:01:57.1 |
HIP 85920 |
3.81 |
| 2026-05-23 12:00 |
17:32:34.55 |
-23:59:45.3 |
HIP 85899 |
12.35 |
| 2026-05-24 00:00 |
17:31:53.04 |
-23:57:32.8 |
HIP 85755 |
6.42 |
| 2026-05-24 12:00 |
17:31:11.42 |
-23:55:19.5 |
HIP 85755 |
3.93 |
| 2026-05-25 00:00 |
17:30:29.68 |
-23:53:05.4 |
HIP 85703 |
5.24 |
| 2026-05-25 12:00 |
17:29:47.85 |
-23:50:50.6 |
HIP 85561 |
9.42 |
| 2026-05-26 00:00 |
17:29:05.92 |
-23:48:35.0 |
HIP 85561 |
1.58 |
| 2026-05-26 12:00 |
17:28:23.92 |
-23:46:18.7 |
HIP 85561 |
10.52 |
| 2026-05-27 00:00 |
17:27:41.84 |
-23:44:01.7 |
HIP 85561 |
20.37 |
| 2026-05-27 12:00 |
17:26:59.70 |
-23:41:44.0 |
HIP 85541 |
29.88 |
| 2026-05-28 00:00 |
17:26:17.50 |
-23:39:25.6 |
HIP 85315 |
29.37 |
| 2026-05-28 12:00 |
17:25:35.26 |
-23:37:06.5 |
HIP 85154 |
24.99 |
| 2026-05-29 00:00 |
17:24:52.97 |
-23:34:46.8 |
HIP 85154 |
19.50 |
| 2026-05-29 12:00 |
17:24:10.66 |
-23:32:26.4 |
HIP 85154 |
18.29 |
| 2026-05-30 00:00 |
17:23:28.33 |
-23:30:05.4 |
HIP 84980 |
19.28 |
| 2026-05-30 12:00 |
17:22:45.98 |
-23:27:43.8 |
HIP 84980 |
11.29 |
| 2026-05-31 00:00 |
17:22:03.63 |
-23:25:21.6 |
HIP 84980 |
9.09 |
| 2026-05-31 12:00 |
17:21:21.28 |
-23:22:58.9 |
HIP 84980 |
15.43 |
| 2026-06-01 00:00 |
17:20:38.94 |
-23:20:35.5 |
HIP 84980 |
24.36 |
| 2026-06-01 12:00 |
17:19:56.63 |
-23:18:11.7 |
HIP 84761 |
19.59 |
| 2026-06-02 00:00 |
17:19:14.34 |
-23:15:47.3 |
HIP 84761 |
16.71 |