| Parameter |
Value |
| Designation |
C/2017 E2 (Tsuchinshan) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-05-12T05:30:48.654720Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:31Z |
| Obs used |
149 |
| NEO |
- |
| M1 |
14.500 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-03-22.0000000 |
| e |
0.89088950 |
| q (au) |
2.353028 |
| a (au) |
21.565554 |
| i (deg) |
79.169792 |
| Ω (om, deg) |
11.562100 |
| ω (w, deg) |
89.463163 |
| M (ma, deg) |
3.087983 |
Magnitude
Scatter + Global Linear
$$
M_a = (13.350 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
13.350 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.911 |
| k |
1.000 |
| 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) |
| 2026-05-12 00:00 |
10:45:59.49 |
-63:36:25.9 |
HIP 52839 |
14.87 |
| 2026-05-12 12:00 |
10:45:54.82 |
-63:35:11.7 |
HIP 52839 |
15.52 |
| 2026-05-13 00:00 |
10:45:50.26 |
-63:33:57.3 |
HIP 52839 |
16.25 |
| 2026-05-13 12:00 |
10:45:45.80 |
-63:32:42.9 |
HIP 52690 |
15.41 |
| 2026-05-14 00:00 |
10:45:41.45 |
-63:31:28.3 |
HIP 52690 |
14.39 |
| 2026-05-14 12:00 |
10:45:37.20 |
-63:30:13.6 |
HIP 52690 |
13.41 |
| 2026-05-15 00:00 |
10:45:33.07 |
-63:28:58.8 |
HIP 52690 |
12.50 |
| 2026-05-15 12:00 |
10:45:29.04 |
-63:27:43.9 |
HIP 52690 |
11.66 |
| 2026-05-16 00:00 |
10:45:25.11 |
-63:26:28.9 |
HIP 52690 |
10.90 |
| 2026-05-16 12:00 |
10:45:21.29 |
-63:25:13.9 |
HIP 52690 |
10.26 |
| 2026-05-17 00:00 |
10:45:17.58 |
-63:23:58.8 |
HIP 52690 |
9.74 |
| 2026-05-17 12:00 |
10:45:13.98 |
-63:22:43.6 |
HIP 52690 |
9.37 |
| 2026-05-18 00:00 |
10:45:10.48 |
-63:21:28.4 |
HIP 52690 |
9.17 |
| 2026-05-18 12:00 |
10:45:07.09 |
-63:20:13.1 |
HIP 52690 |
9.14 |
| 2026-05-19 00:00 |
10:45:03.81 |
-63:18:57.8 |
HIP 52690 |
9.28 |
| 2026-05-19 12:00 |
10:45:00.63 |
-63:17:42.4 |
HIP 52690 |
9.59 |
| 2026-05-20 00:00 |
10:44:57.56 |
-63:16:27.0 |
HIP 52690 |
10.05 |
| 2026-05-20 12:00 |
10:44:54.59 |
-63:15:11.6 |
HIP 52690 |
10.64 |
| 2026-05-21 00:00 |
10:44:51.73 |
-63:13:56.2 |
HIP 52690 |
11.34 |
| 2026-05-21 12:00 |
10:44:48.97 |
-63:12:40.8 |
HIP 52690 |
12.13 |
| 2026-05-22 00:00 |
10:44:46.32 |
-63:11:25.4 |
HIP 52690 |
12.99 |
| 2026-05-22 12:00 |
10:44:43.78 |
-63:10:10.0 |
HIP 52448 |
13.57 |
| 2026-05-23 00:00 |
10:44:41.34 |
-63:08:54.6 |
HIP 52448 |
12.51 |
| 2026-05-23 12:00 |
10:44:39.00 |
-63:07:39.3 |
HIP 52448 |
11.49 |
| 2026-05-24 00:00 |
10:44:36.77 |
-63:06:23.9 |
HIP 52448 |
10.55 |
| 2026-05-24 12:00 |
10:44:34.64 |
-63:05:08.6 |
HIP 52448 |
9.70 |
| 2026-05-25 00:00 |
10:44:32.62 |
-63:03:53.4 |
HIP 52448 |
8.96 |
| 2026-05-25 12:00 |
10:44:30.70 |
-63:02:38.2 |
HIP 52448 |
8.36 |
| 2026-05-26 00:00 |
10:44:28.88 |
-63:01:23.0 |
HIP 52448 |
7.94 |
| 2026-05-26 12:00 |
10:44:27.17 |
-63:00:07.9 |
HIP 52448 |
7.71 |
| 2026-05-27 00:00 |
10:44:25.56 |
-62:58:52.9 |
HIP 52448 |
7.70 |
| 2026-05-27 12:00 |
10:44:24.05 |
-62:57:38.0 |
HIP 52448 |
7.90 |
| 2026-05-28 00:00 |
10:44:22.64 |
-62:56:23.1 |
HIP 52448 |
8.30 |
| 2026-05-28 12:00 |
10:44:21.34 |
-62:55:08.3 |
HIP 52448 |
8.87 |
| 2026-05-29 00:00 |
10:44:20.14 |
-62:53:53.6 |
HIP 52557 |
8.64 |
| 2026-05-29 12:00 |
10:44:19.04 |
-62:52:39.0 |
HIP 52557 |
7.52 |
| 2026-05-30 00:00 |
10:44:18.04 |
-62:51:24.5 |
HIP 52557 |
6.45 |
| 2026-05-30 12:00 |
10:44:17.14 |
-62:50:10.1 |
HIP 52557 |
5.45 |
| 2026-05-31 00:00 |
10:44:16.34 |
-62:48:55.8 |
HIP 52557 |
4.56 |
| 2026-05-31 12:00 |
10:44:15.64 |
-62:47:41.7 |
HIP 52557 |
3.86 |
| 2026-06-01 00:00 |
10:44:15.04 |
-62:46:27.6 |
HIP 52557 |
3.46 |
| 2026-06-01 12:00 |
10:44:14.54 |
-62:45:13.7 |
HIP 52557 |
3.48 |
| 2026-06-02 00:00 |
10:44:14.14 |
-62:44:00.0 |
HIP 52557 |
3.89 |