| 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 |
0.999 |
| 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) |
| 2026-09-20 00:00 |
11:09:16.66 |
-61:06:51.9 |
HIP 54574 |
9.94 |
| 2026-09-20 12:00 |
11:09:26.40 |
-61:07:27.7 |
HIP 54574 |
9.83 |
| 2026-09-21 00:00 |
11:09:36.13 |
-61:08:04.0 |
HIP 54574 |
9.91 |
| 2026-09-21 12:00 |
11:09:45.84 |
-61:08:40.9 |
HIP 54574 |
10.17 |
| 2026-09-22 00:00 |
11:09:55.53 |
-61:09:18.4 |
HIP 54574 |
10.61 |
| 2026-09-22 12:00 |
11:10:05.21 |
-61:09:56.4 |
HIP 54574 |
11.19 |
| 2026-09-23 00:00 |
11:10:14.87 |
-61:10:34.9 |
HIP 54574 |
11.90 |
| 2026-09-23 12:00 |
11:10:24.51 |
-61:11:14.0 |
HIP 54574 |
12.73 |
| 2026-09-24 00:00 |
11:10:34.13 |
-61:11:53.7 |
HIP 54574 |
13.64 |
| 2026-09-24 12:00 |
11:10:43.74 |
-61:12:33.9 |
HIP 54574 |
14.62 |
| 2026-09-25 00:00 |
11:10:53.32 |
-61:13:14.6 |
HIP 54574 |
15.67 |
| 2026-09-25 12:00 |
11:11:02.89 |
-61:13:55.9 |
HIP 54574 |
16.76 |
| 2026-09-26 00:00 |
11:11:12.44 |
-61:14:37.7 |
HIP 54574 |
17.90 |
| 2026-09-26 12:00 |
11:11:21.96 |
-61:15:20.0 |
HIP 54574 |
19.06 |
| 2026-09-27 00:00 |
11:11:31.47 |
-61:16:02.9 |
HIP 54574 |
20.26 |
| 2026-09-27 12:00 |
11:11:40.95 |
-61:16:46.3 |
HIP 54574 |
21.48 |
| 2026-09-28 00:00 |
11:11:50.41 |
-61:17:30.2 |
HIP 54574 |
22.72 |
| 2026-09-28 12:00 |
11:11:59.85 |
-61:18:14.6 |
HIP 54574 |
23.98 |
| 2026-09-29 00:00 |
11:12:09.27 |
-61:18:59.6 |
HIP 54574 |
25.26 |
| 2026-09-29 12:00 |
11:12:18.66 |
-61:19:45.1 |
HIP 54715 |
25.56 |
| 2026-09-30 00:00 |
11:12:28.02 |
-61:20:31.1 |
HIP 54715 |
24.87 |
| 2026-09-30 12:00 |
11:12:37.37 |
-61:21:17.7 |
HIP 54715 |
24.22 |
| 2026-10-01 00:00 |
11:12:46.68 |
-61:22:04.7 |
HIP 54780 |
23.37 |
| 2026-10-01 12:00 |
11:12:55.97 |
-61:22:52.3 |
HIP 54780 |
22.56 |
| 2026-10-02 00:00 |
11:13:05.24 |
-61:23:40.4 |
HIP 54780 |
21.79 |
| 2026-10-02 12:00 |
11:13:14.47 |
-61:24:29.0 |
HIP 54780 |
21.07 |
| 2026-10-03 00:00 |
11:13:23.68 |
-61:25:18.1 |
HIP 54780 |
20.41 |
| 2026-10-03 12:00 |
11:13:32.86 |
-61:26:07.7 |
HIP 54780 |
19.82 |
| 2026-10-04 00:00 |
11:13:42.02 |
-61:26:57.9 |
HIP 54780 |
19.29 |
| 2026-10-04 12:00 |
11:13:51.14 |
-61:27:48.5 |
HIP 54780 |
18.84 |
| 2026-10-05 00:00 |
11:14:00.23 |
-61:28:39.6 |
HIP 54780 |
18.47 |
| 2026-10-05 12:00 |
11:14:09.29 |
-61:29:31.3 |
HIP 54780 |
18.19 |
| 2026-10-06 00:00 |
11:14:18.32 |
-61:30:23.4 |
HIP 54780 |
18.00 |
| 2026-10-06 12:00 |
11:14:27.32 |
-61:31:16.0 |
HIP 54780 |
17.91 |
| 2026-10-07 00:00 |
11:14:36.29 |
-61:32:09.1 |
HIP 54780 |
17.91 |
| 2026-10-07 12:00 |
11:14:45.22 |
-61:33:02.7 |
HIP 54780 |
18.01 |
| 2026-10-08 00:00 |
11:14:54.12 |
-61:33:56.8 |
HIP 54780 |
18.21 |
| 2026-10-08 12:00 |
11:15:02.98 |
-61:34:51.4 |
HIP 54780 |
18.50 |
| 2026-10-09 00:00 |
11:15:11.81 |
-61:35:46.5 |
HIP 55163 |
17.39 |
| 2026-10-09 12:00 |
11:15:20.60 |
-61:36:42.0 |
HIP 55163 |
16.24 |
| 2026-10-10 00:00 |
11:15:29.36 |
-61:37:38.1 |
HIP 55163 |
15.14 |
| 2026-10-10 12:00 |
11:15:38.08 |
-61:38:34.6 |
HIP 55163 |
14.10 |
| 2026-10-11 00:00 |
11:15:46.76 |
-61:39:31.5 |
HIP 55163 |
13.14 |