| Parameter |
Value |
| Designation |
C/2019 M4 (TESS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-09-10T05:31:11.516160Z |
| Orbit solution date (soln_date, UTC) |
2023-05-11T17:42:03Z |
| Obs used |
88 |
| NEO |
- |
| M1 |
4.600 |
| K1 |
10.000 |
| PC |
- |
| Discovery observation (MPC, UTC) |
2019-06-27T02:44:30.768000Z |
| Discovery magnitude (MPC) |
18.90 G |
| Discovery observatory (MPC) |
C57 · TESS |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-09-26.0000000 |
| e |
1.00453441 |
| q (au) |
9.181017 |
| a (au) |
-2024.743895 |
| i (deg) |
65.710801 |
| Ω (om, deg) |
52.573407 |
| ω (w, deg) |
260.252031 |
| M (ma, deg) |
0.000171 |
Magnitude
Scatter + Global Linear
$$
M_a = (-1.188 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
-1.188 |
| n |
6.000 |
| gf |
0.976 |
| gb |
-0.774 |
| 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 |
03:21:22.25 |
+02:19:33.0 |
HIP 15732 |
21.72 |
| 2026-09-20 12:00 |
03:21:18.33 |
+02:19:20.7 |
HIP 15732 |
22.70 |
| 2026-09-21 00:00 |
03:21:14.35 |
+02:19:08.5 |
HIP 15732 |
23.70 |
| 2026-09-21 12:00 |
03:21:10.33 |
+02:18:56.1 |
HIP 15732 |
24.71 |
| 2026-09-22 00:00 |
03:21:06.25 |
+02:18:43.8 |
HIP 15732 |
25.73 |
| 2026-09-22 12:00 |
03:21:02.11 |
+02:18:31.3 |
HIP 15732 |
26.77 |
| 2026-09-23 00:00 |
03:20:57.93 |
+02:18:18.9 |
HIP 15732 |
27.82 |
| 2026-09-23 12:00 |
03:20:53.69 |
+02:18:06.4 |
HIP 15732 |
28.89 |
| 2026-09-24 00:00 |
03:20:49.41 |
+02:17:53.9 |
HIP 15436 |
28.09 |
| 2026-09-24 12:00 |
03:20:45.07 |
+02:17:41.4 |
HIP 15436 |
27.01 |
| 2026-09-25 00:00 |
03:20:40.68 |
+02:17:28.8 |
HIP 15436 |
25.92 |
| 2026-09-25 12:00 |
03:20:36.24 |
+02:17:16.3 |
HIP 15436 |
24.82 |
| 2026-09-26 00:00 |
03:20:31.76 |
+02:17:03.7 |
HIP 15436 |
23.71 |
| 2026-09-26 12:00 |
03:20:27.22 |
+02:16:51.0 |
HIP 15436 |
22.59 |
| 2026-09-27 00:00 |
03:20:22.63 |
+02:16:38.4 |
HIP 15436 |
21.47 |
| 2026-09-27 12:00 |
03:20:18.00 |
+02:16:25.8 |
HIP 15436 |
20.33 |
| 2026-09-28 00:00 |
03:20:13.32 |
+02:16:13.1 |
HIP 15436 |
19.19 |
| 2026-09-28 12:00 |
03:20:08.59 |
+02:16:00.5 |
HIP 15436 |
18.04 |
| 2026-09-29 00:00 |
03:20:03.81 |
+02:15:47.8 |
HIP 15436 |
16.88 |
| 2026-09-29 12:00 |
03:19:58.98 |
+02:15:35.2 |
HIP 15436 |
15.73 |
| 2026-09-30 00:00 |
03:19:54.11 |
+02:15:22.6 |
HIP 15436 |
14.57 |
| 2026-09-30 12:00 |
03:19:49.19 |
+02:15:09.9 |
HIP 15436 |
13.41 |
| 2026-10-01 00:00 |
03:19:44.22 |
+02:14:57.3 |
HIP 15436 |
12.27 |
| 2026-10-01 12:00 |
03:19:39.21 |
+02:14:44.7 |
HIP 15436 |
11.13 |
| 2026-10-02 00:00 |
03:19:34.15 |
+02:14:32.1 |
HIP 15436 |
10.02 |
| 2026-10-02 12:00 |
03:19:29.04 |
+02:14:19.5 |
HIP 15436 |
8.94 |
| 2026-10-03 00:00 |
03:19:23.89 |
+02:14:07.0 |
HIP 15436 |
7.91 |
| 2026-10-03 12:00 |
03:19:18.70 |
+02:13:54.5 |
HIP 15436 |
6.97 |
| 2026-10-04 00:00 |
03:19:13.46 |
+02:13:42.0 |
HIP 15436 |
6.16 |
| 2026-10-04 12:00 |
03:19:08.18 |
+02:13:29.5 |
HIP 15436 |
5.55 |
| 2026-10-05 00:00 |
03:19:02.85 |
+02:13:17.1 |
HIP 15436 |
5.21 |
| 2026-10-05 12:00 |
03:18:57.49 |
+02:13:04.7 |
HIP 15436 |
5.20 |
| 2026-10-06 00:00 |
03:18:52.07 |
+02:12:52.3 |
HIP 15436 |
5.54 |
| 2026-10-06 12:00 |
03:18:46.62 |
+02:12:40.0 |
HIP 15436 |
6.18 |
| 2026-10-07 00:00 |
03:18:41.12 |
+02:12:27.8 |
HIP 15436 |
7.03 |
| 2026-10-07 12:00 |
03:18:35.59 |
+02:12:15.6 |
HIP 15436 |
8.05 |
| 2026-10-08 00:00 |
03:18:30.01 |
+02:12:03.5 |
HIP 15436 |
9.17 |
| 2026-10-08 12:00 |
03:18:24.39 |
+02:11:51.4 |
HIP 15436 |
10.36 |
| 2026-10-09 00:00 |
03:18:18.73 |
+02:11:39.4 |
HIP 15436 |
11.62 |
| 2026-10-09 12:00 |
03:18:13.04 |
+02:11:27.4 |
HIP 15436 |
12.92 |
| 2026-10-10 00:00 |
03:18:07.30 |
+02:11:15.5 |
HIP 15436 |
14.25 |
| 2026-10-10 12:00 |
03:18:01.52 |
+02:11:03.7 |
HIP 15436 |
15.61 |
| 2026-10-11 00:00 |
03:17:55.71 |
+02:10:52.0 |
HIP 15436 |
17.00 |