| Parameter |
Value |
| Designation |
C/2019 T3 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2021-03-02T19:35:34.825920Z |
| Orbit solution date (soln_date, UTC) |
2026-03-07T11:42:49Z |
| Obs used |
1831 |
| NEO |
- |
| M1 |
6.200 |
| K1 |
9.250 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2019-10-06T14:39:22.665600Z |
| Discovery magnitude (MPC) |
18.93 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-06-17.0000000 |
| e |
0.99811606 |
| q (au) |
5.946571 |
| a (au) |
3156.462242 |
| i (deg) |
121.862226 |
| Ω (om, deg) |
139.520856 |
| ω (w, deg) |
112.287720 |
| M (ma, deg) |
0.000590 |
Magnitude
Scatter + Global Linear
$$
M_a = (0.994 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
0.994 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.902 |
| 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
Residuals (Piecewise)
$$\epsilon = a \log_{10} r_{\mathrm{au}} + b$$
| Start (UTC) |
End (UTC) |
a |
b |
| 2019-01-17 |
2021-02-11 |
+8.5481 |
-6.673 |
| 2021-04-20 |
2022-07-29 |
-1.2800 |
+0.613 |
| 2022-07-29 |
2023-08-18 |
+15.5125 |
-13.337 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-07-29 00:00 |
20:51:31.55 |
-46:08:17.5 |
HIP 102790 |
21.88 |
| 2026-07-29 12:00 |
20:51:17.97 |
-46:09:25.8 |
HIP 102790 |
19.33 |
| 2026-07-30 00:00 |
20:51:04.37 |
-46:10:33.4 |
HIP 102790 |
16.80 |
| 2026-07-30 12:00 |
20:50:50.77 |
-46:11:40.4 |
HIP 102790 |
14.29 |
| 2026-07-31 00:00 |
20:50:37.16 |
-46:12:46.7 |
HIP 102790 |
11.83 |
| 2026-07-31 12:00 |
20:50:23.54 |
-46:13:52.4 |
HIP 102790 |
9.45 |
| 2026-08-01 00:00 |
20:50:09.91 |
-46:14:57.4 |
HIP 102790 |
7.21 |
| 2026-08-01 12:00 |
20:49:56.28 |
-46:16:01.7 |
HIP 102790 |
5.31 |
| 2026-08-02 00:00 |
20:49:42.64 |
-46:17:05.3 |
HIP 102790 |
4.21 |
| 2026-08-02 12:00 |
20:49:29.00 |
-46:18:08.3 |
HIP 102790 |
4.52 |
| 2026-08-03 00:00 |
20:49:15.36 |
-46:19:10.5 |
HIP 102790 |
6.04 |
| 2026-08-03 12:00 |
20:49:01.72 |
-46:20:12.1 |
HIP 102790 |
8.09 |
| 2026-08-04 00:00 |
20:48:48.08 |
-46:21:13.0 |
HIP 102790 |
10.37 |
| 2026-08-04 12:00 |
20:48:34.45 |
-46:22:13.2 |
HIP 102790 |
12.75 |
| 2026-08-05 00:00 |
20:48:20.81 |
-46:23:12.7 |
HIP 102790 |
15.18 |
| 2026-08-05 12:00 |
20:48:07.18 |
-46:24:11.6 |
HIP 102790 |
17.64 |
| 2026-08-06 00:00 |
20:47:53.56 |
-46:25:09.7 |
HIP 102763 |
19.74 |
| 2026-08-06 12:00 |
20:47:39.94 |
-46:26:07.1 |
HIP 102763 |
20.88 |
| 2026-08-07 00:00 |
20:47:26.34 |
-46:27:03.9 |
HIP 102763 |
22.25 |
| 2026-08-07 12:00 |
20:47:12.74 |
-46:27:59.9 |
HIP 102763 |
23.81 |
| 2026-08-08 00:00 |
20:46:59.15 |
-46:28:55.2 |
HIP 102437 |
23.67 |
| 2026-08-08 12:00 |
20:46:45.57 |
-46:29:49.8 |
HIP 102437 |
22.88 |
| 2026-08-09 00:00 |
20:46:32.01 |
-46:30:43.7 |
HIP 102437 |
22.34 |
| 2026-08-09 12:00 |
20:46:18.46 |
-46:31:36.9 |
HIP 102437 |
22.06 |
| 2026-08-10 00:00 |
20:46:04.93 |
-46:32:29.3 |
HIP 102437 |
22.05 |
| 2026-08-10 12:00 |
20:45:51.41 |
-46:33:21.1 |
HIP 102437 |
22.32 |
| 2026-08-11 00:00 |
20:45:37.91 |
-46:34:12.1 |
HIP 102437 |
22.84 |
| 2026-08-11 12:00 |
20:45:24.44 |
-46:35:02.4 |
HIP 102437 |
23.59 |
| 2026-08-12 00:00 |
20:45:10.98 |
-46:35:52.0 |
HIP 102247 |
24.00 |
| 2026-08-12 12:00 |
20:44:57.54 |
-46:36:40.8 |
HIP 102247 |
21.58 |
| 2026-08-13 00:00 |
20:44:44.13 |
-46:37:29.0 |
HIP 102247 |
19.16 |
| 2026-08-13 12:00 |
20:44:30.75 |
-46:38:16.4 |
HIP 102247 |
16.77 |
| 2026-08-14 00:00 |
20:44:17.39 |
-46:39:03.1 |
HIP 102247 |
14.39 |
| 2026-08-14 12:00 |
20:44:04.06 |
-46:39:49.0 |
HIP 102247 |
12.05 |
| 2026-08-15 00:00 |
20:43:50.75 |
-46:40:34.2 |
HIP 102247 |
9.75 |
| 2026-08-15 12:00 |
20:43:37.48 |
-46:41:18.7 |
HIP 102247 |
7.52 |
| 2026-08-16 00:00 |
20:43:24.23 |
-46:42:02.5 |
HIP 102247 |
5.46 |
| 2026-08-16 12:00 |
20:43:11.02 |
-46:42:45.5 |
HIP 102247 |
3.80 |
| 2026-08-17 00:00 |
20:42:57.85 |
-46:43:27.9 |
HIP 102247 |
3.23 |
| 2026-08-17 12:00 |
20:42:44.71 |
-46:44:09.4 |
HIP 102247 |
4.20 |
| 2026-08-18 00:00 |
20:42:31.60 |
-46:44:50.3 |
HIP 102247 |
5.99 |
| 2026-08-18 12:00 |
20:42:18.53 |
-46:45:30.4 |
HIP 102247 |
8.06 |
| 2026-08-19 00:00 |
20:42:05.50 |
-46:46:09.8 |
HIP 102247 |
10.24 |