C/2019 F2 (ATLAS)
| Parameter |
Value |
| Designation |
C/2019 F2 (ATLAS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-09-08T21:26:06.544320Z |
| Orbit solution date (soln_date, UTC) |
2025-09-09T12:42:31Z |
| Obs used |
683 |
| NEO |
- |
| M1 |
5.300 |
| K1 |
24.000 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2019-03-26T07:21:56.332800Z |
| Discovery magnitude (MPC) |
17.58 o |
| Discovery observatory (MPC) |
T08 · ATLAS-MLO, Mauna Loa |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-05-07.0000000 |
| e |
0.86507120 |
| q (au) |
2.232882 |
| a (au) |
16.548594 |
| i (deg) |
19.188643 |
| Ω (om, deg) |
175.867930 |
| ω (w, deg) |
10.953986 |
| M (ma, deg) |
358.171475 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.336 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.336 |
| n |
6.000 |
| gf |
1.000 |
| gb |
-0.500 |
| 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 |
| 2019-02-26 |
2019-04-23 |
+11.7951 |
-5.190 |
| 2019-04-23 |
2019-06-26 |
+19.2752 |
-8.502 |
| 2019-12-28 |
2020-07-20 |
+5.9715 |
-2.763 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-02-03 00:00 |
22:10:55.00 |
-04:03:48.7 |
HIP 109442 |
13.23 |
| 2026-02-03 12:00 |
22:11:02.83 |
-04:03:13.6 |
HIP 109442 |
14.15 |
| 2026-02-04 00:00 |
22:11:10.68 |
-04:02:38.4 |
HIP 109442 |
15.30 |
| 2026-02-04 12:00 |
22:11:18.54 |
-04:02:03.0 |
HIP 109442 |
16.61 |
| 2026-02-05 00:00 |
22:11:26.41 |
-04:01:27.3 |
HIP 109442 |
18.07 |
| 2026-02-05 12:00 |
22:11:34.29 |
-04:00:51.5 |
HIP 109442 |
19.63 |
| 2026-02-06 00:00 |
22:11:42.19 |
-04:00:15.5 |
HIP 109442 |
21.28 |
| 2026-02-06 12:00 |
22:11:50.09 |
-03:59:39.2 |
HIP 109698 |
21.74 |
| 2026-02-07 00:00 |
22:11:58.00 |
-03:59:02.8 |
HIP 109698 |
19.68 |
| 2026-02-07 12:00 |
22:12:05.93 |
-03:58:26.3 |
HIP 109698 |
17.61 |
| 2026-02-08 00:00 |
22:12:13.86 |
-03:57:49.5 |
HIP 109698 |
15.54 |
| 2026-02-08 12:00 |
22:12:21.80 |
-03:57:12.6 |
HIP 109698 |
13.47 |
| 2026-02-09 00:00 |
22:12:29.75 |
-03:56:35.4 |
HIP 109698 |
11.40 |
| 2026-02-09 12:00 |
22:12:37.71 |
-03:55:58.1 |
HIP 109698 |
9.33 |
| 2026-02-10 00:00 |
22:12:45.67 |
-03:55:20.7 |
HIP 109698 |
7.26 |
| 2026-02-10 12:00 |
22:12:53.65 |
-03:54:43.0 |
HIP 109698 |
5.20 |
| 2026-02-11 00:00 |
22:13:01.62 |
-03:54:05.2 |
HIP 109698 |
3.16 |
| 2026-02-11 12:00 |
22:13:09.61 |
-03:53:27.3 |
HIP 109698 |
1.28 |
| 2026-02-12 00:00 |
22:13:17.60 |
-03:52:49.1 |
HIP 109698 |
1.43 |
| 2026-02-12 12:00 |
22:13:25.60 |
-03:52:10.8 |
HIP 109698 |
3.35 |
| 2026-02-13 00:00 |
22:13:33.60 |
-03:51:32.4 |
HIP 109698 |
5.40 |
| 2026-02-13 12:00 |
22:13:41.60 |
-03:50:53.8 |
HIP 109733 |
4.36 |
| 2026-02-14 00:00 |
22:13:49.61 |
-03:50:15.0 |
HIP 109733 |
4.14 |
| 2026-02-14 12:00 |
22:13:57.62 |
-03:49:36.1 |
HIP 109733 |
4.91 |
| 2026-02-15 00:00 |
22:14:05.64 |
-03:48:57.0 |
HIP 109733 |
6.32 |
| 2026-02-15 12:00 |
22:14:13.66 |
-03:48:17.8 |
HIP 109733 |
8.04 |
| 2026-02-16 00:00 |
22:14:21.68 |
-03:47:38.5 |
HIP 109733 |
9.91 |
| 2026-02-16 12:00 |
22:14:29.70 |
-03:46:59.0 |
HIP 109733 |
11.85 |
| 2026-02-17 00:00 |
22:14:37.72 |
-03:46:19.4 |
HIP 109733 |
13.85 |
| 2026-02-17 12:00 |
22:14:45.75 |
-03:45:39.6 |
HIP 109733 |
15.87 |
| 2026-02-18 00:00 |
22:14:53.77 |
-03:44:59.7 |
HIP 109733 |
17.92 |
| 2026-02-18 12:00 |
22:15:01.79 |
-03:44:19.7 |
HIP 109733 |
19.97 |
| 2026-02-19 00:00 |
22:15:09.82 |
-03:43:39.6 |
HIP 109733 |
22.04 |
| 2026-02-19 12:00 |
22:15:17.84 |
-03:42:59.3 |
HIP 109733 |
24.12 |
| 2026-02-20 00:00 |
22:15:25.86 |
-03:42:18.9 |
HIP 109733 |
26.20 |
| 2026-02-20 12:00 |
22:15:33.88 |
-03:41:38.4 |
HIP 109733 |
28.28 |
| 2026-02-21 00:00 |
22:15:41.89 |
-03:40:57.8 |
HIP 109733 |
30.37 |
| 2026-02-21 12:00 |
22:15:49.90 |
-03:40:17.1 |
HIP 109733 |
32.46 |
| 2026-02-22 00:00 |
22:15:57.91 |
-03:39:36.3 |
HIP 109733 |
34.56 |
| 2026-02-22 12:00 |
22:16:05.92 |
-03:38:55.3 |
HIP 109733 |
36.65 |
| 2026-02-23 00:00 |
22:16:13.92 |
-03:38:14.3 |
HIP 109733 |
38.75 |
| 2026-02-23 12:00 |
22:16:21.92 |
-03:37:33.2 |
HIP 110106 |
38.86 |
| 2026-02-24 00:00 |
22:16:29.91 |
-03:36:51.9 |
HIP 110106 |
36.97 |