| Parameter |
Value |
| Designation |
126P/IRAS |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2023-07-05T08:31:56.219520Z |
| Orbit solution date (soln_date, UTC) |
2025-10-30T09:34:36Z |
| Obs used |
1717 |
| NEO |
- |
| M1 |
11.800 |
| K1 |
11.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-05-27.0000000 |
| e |
0.69627539 |
| q (au) |
1.713008 |
| a (au) |
5.640004 |
| i (deg) |
45.869371 |
| Ω (om, deg) |
357.862226 |
| ω (w, deg) |
356.523683 |
| M (ma, deg) |
303.387535 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.785 + 5.260\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.785 |
| n |
5.260 |
| gf |
1.000 |
| gb |
-1.000 |
| k |
0.992 |
| 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
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
11:10:22.99 |
+26:02:23.4 |
HIP 54648 |
10.04 |
| 2026-09-20 12:00 |
11:10:38.17 |
+26:00:43.4 |
HIP 54648 |
6.71 |
| 2026-09-21 00:00 |
11:10:53.33 |
+25:59:04.1 |
HIP 54648 |
4.25 |
| 2026-09-21 12:00 |
11:11:08.47 |
+25:57:25.3 |
HIP 54648 |
4.44 |
| 2026-09-22 00:00 |
11:11:23.58 |
+25:55:47.2 |
HIP 54648 |
7.05 |
| 2026-09-22 12:00 |
11:11:38.66 |
+25:54:09.7 |
HIP 54648 |
10.39 |
| 2026-09-23 00:00 |
11:11:53.71 |
+25:52:32.8 |
HIP 54648 |
13.93 |
| 2026-09-23 12:00 |
11:12:08.73 |
+25:50:56.5 |
HIP 54648 |
17.55 |
| 2026-09-24 00:00 |
11:12:23.72 |
+25:49:20.9 |
HIP 54648 |
21.20 |
| 2026-09-24 12:00 |
11:12:38.68 |
+25:47:45.9 |
HIP 54648 |
24.86 |
| 2026-09-25 00:00 |
11:12:53.61 |
+25:46:11.6 |
HIP 54906 |
22.72 |
| 2026-09-25 12:00 |
11:13:08.51 |
+25:44:37.8 |
HIP 54906 |
19.19 |
| 2026-09-26 00:00 |
11:13:23.38 |
+25:43:04.8 |
HIP 54906 |
15.74 |
| 2026-09-26 12:00 |
11:13:38.22 |
+25:41:32.3 |
HIP 54906 |
12.44 |
| 2026-09-27 00:00 |
11:13:53.02 |
+25:40:00.5 |
HIP 54906 |
9.43 |
| 2026-09-27 12:00 |
11:14:07.79 |
+25:38:29.4 |
HIP 54906 |
7.06 |
| 2026-09-28 00:00 |
11:14:22.52 |
+25:36:58.9 |
HIP 54906 |
6.13 |
| 2026-09-28 12:00 |
11:14:37.22 |
+25:35:29.1 |
HIP 54906 |
7.19 |
| 2026-09-29 00:00 |
11:14:51.89 |
+25:33:59.9 |
HIP 54906 |
9.59 |
| 2026-09-29 12:00 |
11:15:06.52 |
+25:32:31.4 |
HIP 54906 |
12.58 |
| 2026-09-30 00:00 |
11:15:21.11 |
+25:31:03.5 |
HIP 54906 |
15.81 |
| 2026-09-30 12:00 |
11:15:35.67 |
+25:29:36.3 |
HIP 54906 |
19.17 |
| 2026-10-01 00:00 |
11:15:50.18 |
+25:28:09.8 |
HIP 54906 |
22.58 |
| 2026-10-01 12:00 |
11:16:04.66 |
+25:26:44.0 |
HIP 55166 |
21.76 |
| 2026-10-02 00:00 |
11:16:19.11 |
+25:25:18.8 |
HIP 55166 |
18.62 |
| 2026-10-02 12:00 |
11:16:33.51 |
+25:23:54.4 |
HIP 55166 |
15.68 |
| 2026-10-03 00:00 |
11:16:47.87 |
+25:22:30.6 |
HIP 55166 |
13.03 |
| 2026-10-03 12:00 |
11:17:02.19 |
+25:21:07.5 |
HIP 55166 |
10.91 |
| 2026-10-04 00:00 |
11:17:16.47 |
+25:19:45.1 |
HIP 55166 |
9.62 |
| 2026-10-04 12:00 |
11:17:30.71 |
+25:18:23.4 |
HIP 55166 |
9.52 |
| 2026-10-05 00:00 |
11:17:44.91 |
+25:17:02.4 |
HIP 55212 |
9.19 |
| 2026-10-05 12:00 |
11:17:59.06 |
+25:15:42.1 |
HIP 55212 |
5.74 |
| 2026-10-06 00:00 |
11:18:13.17 |
+25:14:22.5 |
HIP 55212 |
2.34 |
| 2026-10-06 12:00 |
11:18:27.23 |
+25:13:03.6 |
HIP 55212 |
1.35 |
| 2026-10-07 00:00 |
11:18:41.25 |
+25:11:45.5 |
HIP 55212 |
4.66 |
| 2026-10-07 12:00 |
11:18:55.22 |
+25:10:28.1 |
HIP 55212 |
8.06 |
| 2026-10-08 00:00 |
11:19:09.15 |
+25:09:11.4 |
HIP 55212 |
11.45 |
| 2026-10-08 12:00 |
11:19:23.02 |
+25:07:55.4 |
HIP 55212 |
14.83 |
| 2026-10-09 00:00 |
11:19:36.85 |
+25:06:40.1 |
HIP 55212 |
18.20 |
| 2026-10-09 12:00 |
11:19:50.63 |
+25:05:25.6 |
HIP 55212 |
21.55 |
| 2026-10-10 00:00 |
11:20:04.36 |
+25:04:11.9 |
HIP 55212 |
24.89 |
| 2026-10-10 12:00 |
11:20:18.04 |
+25:02:58.9 |
HIP 55212 |
28.22 |
| 2026-10-11 00:00 |
11:20:31.67 |
+25:01:46.6 |
HIP 55367 |
27.42 |