| Parameter |
Value |
| Designation |
C/2018 S2 (TESS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2018-11-05T04:38:14.709120Z |
| Orbit solution date (soln_date, UTC) |
2022-08-25T20:42:05Z |
| Obs used |
803 |
| NEO |
- |
| M1 |
6.700 |
| K1 |
11.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2018-09-23T18:44:41.078400Z |
| Discovery magnitude (MPC) |
18.50 G |
| Discovery observatory (MPC) |
C57 · TESS |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-04-11.0000000 |
| e |
0.61491477 |
| q (au) |
5.470619 |
| a (au) |
14.206254 |
| i (deg) |
64.220443 |
| Ω (om, deg) |
85.125919 |
| ω (w, deg) |
290.683496 |
| M (ma, deg) |
356.167772 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.539 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.539 |
| n |
6.000 |
| gf |
0.973 |
| gb |
-0.935 |
| k |
0.800 |
| δ90 |
9.920 |
| 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) |
| 2026-07-29 00:00 |
09:22:26.85 |
+63:54:00.3 |
HIP 46247 |
21.83 |
| 2026-07-29 12:00 |
09:22:47.60 |
+63:53:28.5 |
HIP 46247 |
19.64 |
| 2026-07-30 00:00 |
09:23:08.36 |
+63:52:57.2 |
HIP 46247 |
17.49 |
| 2026-07-30 12:00 |
09:23:29.15 |
+63:52:26.5 |
HIP 46247 |
15.38 |
| 2026-07-31 00:00 |
09:23:49.94 |
+63:51:56.2 |
HIP 46247 |
13.35 |
| 2026-07-31 12:00 |
09:24:10.76 |
+63:51:26.5 |
HIP 46247 |
11.44 |
| 2026-08-01 00:00 |
09:24:31.58 |
+63:50:57.3 |
HIP 46247 |
9.70 |
| 2026-08-01 12:00 |
09:24:52.42 |
+63:50:28.6 |
HIP 46247 |
8.26 |
| 2026-08-02 00:00 |
09:25:13.27 |
+63:50:00.4 |
HIP 46247 |
7.30 |
| 2026-08-02 12:00 |
09:25:34.14 |
+63:49:32.8 |
HIP 46247 |
7.00 |
| 2026-08-03 00:00 |
09:25:55.01 |
+63:49:05.7 |
HIP 46247 |
7.46 |
| 2026-08-03 12:00 |
09:26:15.90 |
+63:48:39.2 |
HIP 46247 |
8.55 |
| 2026-08-04 00:00 |
09:26:36.80 |
+63:48:13.1 |
HIP 46247 |
10.07 |
| 2026-08-04 12:00 |
09:26:57.71 |
+63:47:47.7 |
HIP 46247 |
11.86 |
| 2026-08-05 00:00 |
09:27:18.62 |
+63:47:22.7 |
HIP 46247 |
13.81 |
| 2026-08-05 12:00 |
09:27:39.55 |
+63:46:58.3 |
HIP 46247 |
15.86 |
| 2026-08-06 00:00 |
09:28:00.48 |
+63:46:34.5 |
HIP 46247 |
17.98 |
| 2026-08-06 12:00 |
09:28:21.42 |
+63:46:11.2 |
HIP 46247 |
20.14 |
| 2026-08-07 00:00 |
09:28:42.37 |
+63:45:48.5 |
HIP 46684 |
18.15 |
| 2026-08-07 12:00 |
09:29:03.33 |
+63:45:26.3 |
HIP 46684 |
16.01 |
| 2026-08-08 00:00 |
09:29:24.29 |
+63:45:04.7 |
HIP 46684 |
13.93 |
| 2026-08-08 12:00 |
09:29:45.25 |
+63:44:43.6 |
HIP 46684 |
11.97 |
| 2026-08-09 00:00 |
09:30:06.22 |
+63:44:23.1 |
HIP 46684 |
10.19 |
| 2026-08-09 12:00 |
09:30:27.19 |
+63:44:03.2 |
HIP 46684 |
8.68 |
| 2026-08-10 00:00 |
09:30:48.17 |
+63:43:43.8 |
HIP 46684 |
7.62 |
| 2026-08-10 12:00 |
09:31:09.15 |
+63:43:25.0 |
HIP 46684 |
7.20 |
| 2026-08-11 00:00 |
09:31:30.12 |
+63:43:06.8 |
HIP 46684 |
7.55 |
| 2026-08-11 12:00 |
09:31:51.10 |
+63:42:49.1 |
HIP 46684 |
8.55 |
| 2026-08-12 00:00 |
09:32:12.08 |
+63:42:32.1 |
HIP 46684 |
10.02 |
| 2026-08-12 12:00 |
09:32:33.06 |
+63:42:15.6 |
HIP 46684 |
11.78 |
| 2026-08-13 00:00 |
09:32:54.04 |
+63:41:59.7 |
HIP 46684 |
13.73 |
| 2026-08-13 12:00 |
09:33:15.01 |
+63:41:44.4 |
HIP 46684 |
15.78 |
| 2026-08-14 00:00 |
09:33:35.98 |
+63:41:29.6 |
HIP 46684 |
17.91 |
| 2026-08-14 12:00 |
09:33:56.95 |
+63:41:15.5 |
HIP 46684 |
20.09 |
| 2026-08-15 00:00 |
09:34:17.91 |
+63:41:01.9 |
HIP 46684 |
22.30 |
| 2026-08-15 12:00 |
09:34:38.87 |
+63:40:49.0 |
HIP 46684 |
24.54 |
| 2026-08-16 00:00 |
09:34:59.82 |
+63:40:36.6 |
HIP 46684 |
26.79 |
| 2026-08-16 12:00 |
09:35:20.77 |
+63:40:24.8 |
HIP 46684 |
29.06 |
| 2026-08-17 00:00 |
09:35:41.70 |
+63:40:13.7 |
HIP 47062 |
29.60 |
| 2026-08-17 12:00 |
09:36:02.63 |
+63:40:03.1 |
HIP 47062 |
29.64 |
| 2026-08-18 00:00 |
09:36:23.55 |
+63:39:53.1 |
HIP 47062 |
29.88 |
| 2026-08-18 12:00 |
09:36:44.46 |
+63:39:43.8 |
HIP 47062 |
30.31 |
| 2026-08-19 00:00 |
09:37:05.37 |
+63:39:35.0 |
HIP 47062 |
30.92 |