| 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) |
| 2026-06-01 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 |
| 2026-06-02 12:00 |
17:18:32.10 |
-23:13:22.5 |
HIP 84761 |
19.36 |
| 2026-06-03 00:00 |
17:17:49.89 |
-23:10:57.2 |
HIP 84761 |
25.89 |
| 2026-06-03 12:00 |
17:17:07.74 |
-23:08:31.4 |
HIP 84761 |
34.13 |
| 2026-06-04 00:00 |
17:16:25.66 |
-23:06:05.3 |
HIP 84543 |
38.79 |
| 2026-06-04 12:00 |
17:15:43.64 |
-23:03:38.7 |
HIP 84299 |
36.79 |
| 2026-06-05 00:00 |
17:15:01.71 |
-23:01:11.7 |
HIP 84299 |
29.55 |
| 2026-06-05 12:00 |
17:14:19.85 |
-22:58:44.4 |
HIP 84299 |
24.31 |
| 2026-06-06 00:00 |
17:13:38.10 |
-22:56:16.8 |
HIP 84172 |
17.20 |
| 2026-06-06 12:00 |
17:12:56.44 |
-22:53:48.9 |
HIP 84172 |
7.78 |
| 2026-06-07 00:00 |
17:12:14.90 |
-22:51:20.6 |
HIP 84172 |
4.61 |
| 2026-06-07 12:00 |
17:11:33.47 |
-22:48:52.2 |
HIP 84172 |
13.29 |
| 2026-06-08 00:00 |
17:10:52.18 |
-22:46:23.5 |
HIP 84019 |
7.19 |
| 2026-06-08 12:00 |
17:10:11.01 |
-22:43:54.5 |
HIP 84019 |
5.10 |
| 2026-06-09 00:00 |
17:09:29.98 |
-22:41:25.5 |
HIP 84019 |
13.86 |
| 2026-06-09 12:00 |
17:08:49.11 |
-22:38:56.2 |
HIP 84019 |
23.41 |
| 2026-06-10 00:00 |
17:08:08.39 |
-22:36:26.8 |
HIP 84019 |
33.05 |
| 2026-06-10 12:00 |
17:07:27.83 |
-22:33:57.4 |
HIP 83662 |
26.77 |
| 2026-06-11 00:00 |
17:06:47.45 |
-22:31:27.8 |
HIP 83662 |
22.75 |
| 2026-06-11 12:00 |
17:06:07.25 |
-22:28:58.3 |
HIP 83662 |
22.46 |
| 2026-06-12 00:00 |
17:05:27.23 |
-22:26:28.7 |
HIP 83629 |
22.13 |
| 2026-06-12 12:00 |
17:04:47.40 |
-22:23:59.1 |
HIP 83629 |
21.99 |
| 2026-06-13 00:00 |
17:04:07.78 |
-22:21:29.6 |
HIP 83597 |
25.36 |
| 2026-06-13 12:00 |
17:03:28.36 |
-22:19:00.1 |
HIP 83396 |
22.13 |
| 2026-06-14 00:00 |
17:02:49.16 |
-22:16:30.7 |
HIP 83396 |
21.86 |
| 2026-06-14 12:00 |
17:02:10.18 |
-22:14:01.4 |
HIP 83396 |
25.33 |
| 2026-06-15 00:00 |
17:01:31.43 |
-22:11:32.3 |
HIP 83211 |
16.60 |
| 2026-06-15 12:00 |
17:00:52.91 |
-22:09:03.4 |
HIP 83211 |
7.37 |
| 2026-06-16 00:00 |
17:00:14.64 |
-22:06:34.7 |
HIP 83211 |
2.08 |
| 2026-06-16 12:00 |
16:59:36.61 |
-22:04:06.2 |
HIP 83179 |
7.38 |
| 2026-06-17 00:00 |
16:58:58.84 |
-22:01:38.0 |
HIP 83179 |
16.08 |
| 2026-06-17 12:00 |
16:58:21.34 |
-21:59:10.0 |
HIP 83005 |
15.61 |
| 2026-06-18 00:00 |
16:57:44.09 |
-21:56:42.4 |
HIP 83005 |
10.21 |
| 2026-06-18 12:00 |
16:57:07.12 |
-21:54:15.1 |
HIP 83005 |
11.19 |
| 2026-06-19 00:00 |
16:56:30.43 |
-21:51:48.2 |
HIP 83005 |
17.42 |
| 2026-06-19 12:00 |
16:55:54.02 |
-21:49:21.7 |
HIP 82822 |
15.99 |
| 2026-06-20 00:00 |
16:55:17.90 |
-21:46:55.6 |
HIP 82734 |
10.88 |
| 2026-06-20 12:00 |
16:54:42.08 |
-21:44:29.9 |
HIP 82734 |
8.32 |
| 2026-06-21 00:00 |
16:54:06.55 |
-21:42:04.7 |
HIP 82734 |
13.00 |
| 2026-06-21 12:00 |
16:53:31.33 |
-21:39:40.0 |
HIP 82734 |
20.35 |
| 2026-06-22 00:00 |
16:52:56.41 |
-21:37:15.8 |
HIP 82519 |
22.33 |