| Parameter |
Value |
| Designation |
172P/Yeung |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2017-03-09T19:52:33.948480Z |
| Orbit solution date (soln_date, UTC) |
2025-06-26T10:13:18Z |
| Obs used |
794 |
| NEO |
- |
| M1 |
14.800 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2013-06-05.0000000 |
| e |
0.22433762 |
| q (au) |
3.237563 |
| a (au) |
4.173933 |
| i (deg) |
11.337557 |
| Ω (om, deg) |
33.678106 |
| ω (w, deg) |
208.775652 |
| M (ma, deg) |
201.211793 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.025 + 2.597\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.025 |
| n |
2.597 |
| gf |
0.999 |
| gb |
-0.747 |
| k |
0.986 |
| 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
Finding Chart
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-05-12 00:00 |
19:17:59.67 |
-34:35:54.9 |
HIP 94844 |
4.81 |
| 2026-05-12 12:00 |
19:18:00.90 |
-34:37:59.2 |
HIP 94844 |
6.90 |
| 2026-05-13 00:00 |
19:18:01.77 |
-34:40:03.9 |
HIP 94844 |
8.98 |
| 2026-05-13 12:00 |
19:18:02.30 |
-34:42:09.1 |
HIP 94844 |
11.07 |
| 2026-05-14 00:00 |
19:18:02.48 |
-34:44:14.6 |
HIP 94844 |
13.15 |
| 2026-05-14 12:00 |
19:18:02.30 |
-34:46:20.5 |
HIP 94844 |
15.23 |
| 2026-05-15 00:00 |
19:18:01.78 |
-34:48:26.8 |
HIP 94844 |
17.32 |
| 2026-05-15 12:00 |
19:18:00.91 |
-34:50:33.5 |
HIP 94844 |
19.42 |
| 2026-05-16 00:00 |
19:17:59.68 |
-34:52:40.4 |
HIP 94891 |
20.65 |
| 2026-05-16 12:00 |
19:17:58.11 |
-34:54:47.7 |
HIP 94891 |
18.84 |
| 2026-05-17 00:00 |
19:17:56.18 |
-34:56:55.3 |
HIP 94891 |
17.14 |
| 2026-05-17 12:00 |
19:17:53.91 |
-34:59:03.1 |
HIP 94891 |
15.60 |
| 2026-05-18 00:00 |
19:17:51.28 |
-35:01:11.2 |
HIP 94891 |
14.27 |
| 2026-05-18 12:00 |
19:17:48.31 |
-35:03:19.6 |
HIP 94764 |
12.89 |
| 2026-05-19 00:00 |
19:17:44.99 |
-35:05:28.2 |
HIP 94764 |
11.14 |
| 2026-05-19 12:00 |
19:17:41.32 |
-35:07:36.9 |
HIP 94764 |
9.53 |
| 2026-05-20 00:00 |
19:17:37.30 |
-35:09:45.9 |
HIP 94764 |
8.16 |
| 2026-05-20 12:00 |
19:17:32.93 |
-35:11:55.1 |
HIP 94764 |
7.22 |
| 2026-05-21 00:00 |
19:17:28.22 |
-35:14:04.3 |
HIP 94764 |
6.90 |
| 2026-05-21 12:00 |
19:17:23.16 |
-35:16:13.7 |
HIP 94764 |
7.32 |
| 2026-05-22 00:00 |
19:17:17.76 |
-35:18:23.2 |
HIP 94764 |
8.39 |
| 2026-05-22 12:00 |
19:17:12.02 |
-35:20:32.8 |
HIP 94764 |
9.93 |
| 2026-05-23 00:00 |
19:17:05.94 |
-35:22:42.5 |
HIP 94764 |
11.77 |
| 2026-05-23 12:00 |
19:16:59.51 |
-35:24:52.2 |
HIP 94764 |
13.82 |
| 2026-05-24 00:00 |
19:16:52.74 |
-35:27:01.9 |
HIP 94764 |
16.02 |
| 2026-05-24 12:00 |
19:16:45.64 |
-35:29:11.6 |
HIP 94764 |
18.31 |
| 2026-05-25 00:00 |
19:16:38.19 |
-35:31:21.3 |
HIP 94764 |
20.70 |
| 2026-05-25 12:00 |
19:16:30.41 |
-35:33:31.0 |
HIP 94764 |
23.15 |
| 2026-05-26 00:00 |
19:16:22.30 |
-35:35:40.6 |
HIP 94764 |
25.67 |
| 2026-05-26 12:00 |
19:16:13.85 |
-35:37:50.1 |
HIP 94549 |
24.28 |
| 2026-05-27 00:00 |
19:16:05.06 |
-35:39:59.4 |
HIP 94549 |
21.58 |
| 2026-05-27 12:00 |
19:15:55.95 |
-35:42:08.7 |
HIP 94549 |
18.85 |
| 2026-05-28 00:00 |
19:15:46.51 |
-35:44:17.8 |
HIP 94549 |
16.11 |
| 2026-05-28 12:00 |
19:15:36.74 |
-35:46:26.7 |
HIP 94549 |
13.36 |
| 2026-05-29 00:00 |
19:15:26.64 |
-35:48:35.4 |
HIP 94549 |
10.65 |
| 2026-05-29 12:00 |
19:15:16.21 |
-35:50:43.8 |
HIP 94549 |
8.06 |
| 2026-05-30 00:00 |
19:15:05.46 |
-35:52:52.1 |
HIP 94549 |
5.81 |
| 2026-05-30 12:00 |
19:14:54.39 |
-35:55:00.0 |
HIP 94549 |
4.55 |
| 2026-05-31 00:00 |
19:14:43.00 |
-35:57:07.6 |
HIP 94549 |
5.16 |
| 2026-05-31 12:00 |
19:14:31.30 |
-35:59:14.9 |
HIP 94549 |
7.24 |
| 2026-06-01 00:00 |
19:14:19.27 |
-36:01:21.9 |
HIP 94549 |
9.93 |
| 2026-06-01 12:00 |
19:14:06.93 |
-36:03:28.5 |
HIP 94549 |
12.90 |
| 2026-06-02 00:00 |
19:13:54.28 |
-36:05:34.7 |
HIP 94549 |
16.01 |