C/2018 S2 (TESS)
| 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
$$
M_a = (8.540 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.540 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.935 |
| k |
0.800 |
| 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) |
| 2026-02-03 00:00 |
09:05:44.07 |
+69:02:04.4 |
HIP 44544 |
6.41 |
| 2026-02-03 12:00 |
09:05:23.97 |
+69:02:42.5 |
HIP 44544 |
4.73 |
| 2026-02-04 00:00 |
09:05:03.85 |
+69:03:19.5 |
HIP 44544 |
3.31 |
| 2026-02-04 12:00 |
09:04:43.74 |
+69:03:55.3 |
HIP 44544 |
2.59 |
| 2026-02-05 00:00 |
09:04:23.62 |
+69:04:30.0 |
HIP 44544 |
3.08 |
| 2026-02-05 12:00 |
09:04:03.51 |
+69:05:03.5 |
HIP 44544 |
4.39 |
| 2026-02-06 00:00 |
09:03:43.40 |
+69:05:35.9 |
HIP 44544 |
6.00 |
| 2026-02-06 12:00 |
09:03:23.30 |
+69:06:07.1 |
HIP 44544 |
7.71 |
| 2026-02-07 00:00 |
09:03:03.21 |
+69:06:37.2 |
HIP 44544 |
9.48 |
| 2026-02-07 12:00 |
09:02:43.13 |
+69:07:06.1 |
HIP 44544 |
11.26 |
| 2026-02-08 00:00 |
09:02:23.07 |
+69:07:33.9 |
HIP 44544 |
13.05 |
| 2026-02-08 12:00 |
09:02:03.03 |
+69:08:00.5 |
HIP 44544 |
14.85 |
| 2026-02-09 00:00 |
09:01:43.01 |
+69:08:25.9 |
HIP 44544 |
16.64 |
| 2026-02-09 12:00 |
09:01:23.02 |
+69:08:50.2 |
HIP 44396 |
18.05 |
| 2026-02-10 00:00 |
09:01:03.06 |
+69:09:13.4 |
HIP 44396 |
19.11 |
| 2026-02-10 12:00 |
09:00:43.12 |
+69:09:35.4 |
HIP 44396 |
20.27 |
| 2026-02-11 00:00 |
09:00:23.23 |
+69:09:56.2 |
HIP 44396 |
21.50 |
| 2026-02-11 12:00 |
09:00:03.37 |
+69:10:15.9 |
HIP 44396 |
22.80 |
| 2026-02-12 00:00 |
08:59:43.55 |
+69:10:34.5 |
HIP 44396 |
24.14 |
| 2026-02-12 12:00 |
08:59:23.77 |
+69:10:51.8 |
HIP 44396 |
25.52 |
| 2026-02-13 00:00 |
08:59:04.05 |
+69:11:08.1 |
HIP 44396 |
26.93 |
| 2026-02-13 12:00 |
08:58:44.37 |
+69:11:23.2 |
HIP 44396 |
28.37 |
| 2026-02-14 00:00 |
08:58:24.74 |
+69:11:37.1 |
HIP 44396 |
29.82 |
| 2026-02-14 12:00 |
08:58:05.17 |
+69:11:50.0 |
HIP 44396 |
31.30 |
| 2026-02-15 00:00 |
08:57:45.66 |
+69:12:01.6 |
HIP 44396 |
32.78 |
| 2026-02-15 12:00 |
08:57:26.21 |
+69:12:12.2 |
HIP 44396 |
34.28 |
| 2026-02-16 00:00 |
08:57:06.83 |
+69:12:21.5 |
HIP 44396 |
35.78 |
| 2026-02-16 12:00 |
08:56:47.51 |
+69:12:29.8 |
HIP 43390 |
35.54 |
| 2026-02-17 00:00 |
08:56:28.26 |
+69:12:36.9 |
HIP 43390 |
33.87 |
| 2026-02-17 12:00 |
08:56:09.09 |
+69:12:43.0 |
HIP 43390 |
32.21 |
| 2026-02-18 00:00 |
08:55:49.99 |
+69:12:47.8 |
HIP 43390 |
30.57 |
| 2026-02-18 12:00 |
08:55:30.97 |
+69:12:51.6 |
HIP 43390 |
28.95 |
| 2026-02-19 00:00 |
08:55:12.04 |
+69:12:54.2 |
HIP 43390 |
27.35 |
| 2026-02-19 12:00 |
08:54:53.18 |
+69:12:55.8 |
HIP 43390 |
25.77 |
| 2026-02-20 00:00 |
08:54:34.42 |
+69:12:56.2 |
HIP 43390 |
24.22 |
| 2026-02-20 12:00 |
08:54:15.75 |
+69:12:55.5 |
HIP 43390 |
22.70 |
| 2026-02-21 00:00 |
08:53:57.17 |
+69:12:53.8 |
HIP 43390 |
21.21 |
| 2026-02-21 12:00 |
08:53:38.68 |
+69:12:50.9 |
HIP 43390 |
19.77 |
| 2026-02-22 00:00 |
08:53:20.30 |
+69:12:47.0 |
HIP 43390 |
18.37 |
| 2026-02-22 12:00 |
08:53:02.01 |
+69:12:41.9 |
HIP 43390 |
17.03 |
| 2026-02-23 00:00 |
08:52:43.83 |
+69:12:35.8 |
HIP 43390 |
15.76 |
| 2026-02-23 12:00 |
08:52:25.75 |
+69:12:28.6 |
HIP 43390 |
14.58 |
| 2026-02-24 00:00 |
08:52:07.79 |
+69:12:20.4 |
HIP 43390 |
13.51 |