| Parameter |
Value |
| Designation |
C/2019 J2 (Palomar) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2019-07-19T17:09:39.836160Z |
| Orbit solution date (soln_date, UTC) |
2021-09-04T23:42:59Z |
| Obs used |
312 |
| NEO |
- |
| M1 |
9.400 |
| K1 |
22.500 |
| PC |
0.030 |
| Discovery observation (MPC, UTC) |
2019-05-09T11:22:13.987200Z |
| Discovery magnitude (MPC) |
16.86 r |
| Discovery observatory (MPC) |
I41 · Palomar Mountain–ZTF |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2019-06-10.0000000 |
| e |
0.99767395 |
| q (au) |
1.727002 |
| a (au) |
742.459732 |
| i (deg) |
105.135744 |
| Ω (om, deg) |
25.468130 |
| ω (w, deg) |
98.695628 |
| M (ma, deg) |
359.998065 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.283 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.283 |
| 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 |
| 2019-04-27 |
2019-07-19 |
-32.7489 |
+9.328 |
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 |
09:30:49.11 |
-49:01:30.3 |
HIP 46793 |
25.82 |
| 2026-07-29 12:00 |
09:30:56.73 |
-49:01:26.9 |
HIP 46793 |
25.29 |
| 2026-07-30 00:00 |
09:31:04.36 |
-49:01:24.1 |
HIP 46793 |
24.81 |
| 2026-07-30 12:00 |
09:31:12.01 |
-49:01:21.9 |
HIP 46793 |
24.37 |
| 2026-07-31 00:00 |
09:31:19.67 |
-49:01:20.5 |
HIP 46914 |
23.78 |
| 2026-07-31 12:00 |
09:31:27.34 |
-49:01:19.6 |
HIP 46914 |
22.52 |
| 2026-08-01 00:00 |
09:31:35.02 |
-49:01:19.5 |
HIP 46914 |
21.27 |
| 2026-08-01 12:00 |
09:31:42.71 |
-49:01:19.9 |
HIP 46914 |
20.01 |
| 2026-08-02 00:00 |
09:31:50.41 |
-49:01:21.1 |
HIP 46914 |
18.75 |
| 2026-08-02 12:00 |
09:31:58.13 |
-49:01:22.9 |
HIP 46914 |
17.48 |
| 2026-08-03 00:00 |
09:32:05.85 |
-49:01:25.4 |
HIP 46914 |
16.22 |
| 2026-08-03 12:00 |
09:32:13.58 |
-49:01:28.5 |
HIP 46914 |
14.96 |
| 2026-08-04 00:00 |
09:32:21.32 |
-49:01:32.3 |
HIP 46914 |
13.70 |
| 2026-08-04 12:00 |
09:32:29.07 |
-49:01:36.7 |
HIP 46914 |
12.45 |
| 2026-08-05 00:00 |
09:32:36.83 |
-49:01:41.8 |
HIP 46914 |
11.19 |
| 2026-08-05 12:00 |
09:32:44.60 |
-49:01:47.5 |
HIP 46914 |
9.94 |
| 2026-08-06 00:00 |
09:32:52.37 |
-49:01:53.9 |
HIP 46914 |
8.70 |
| 2026-08-06 12:00 |
09:33:00.14 |
-49:02:01.0 |
HIP 46914 |
7.48 |
| 2026-08-07 00:00 |
09:33:07.93 |
-49:02:08.7 |
HIP 46914 |
6.28 |
| 2026-08-07 12:00 |
09:33:15.72 |
-49:02:17.0 |
HIP 46914 |
5.13 |
| 2026-08-08 00:00 |
09:33:23.51 |
-49:02:26.1 |
HIP 46914 |
4.05 |
| 2026-08-08 12:00 |
09:33:31.31 |
-49:02:35.7 |
HIP 46914 |
3.16 |
| 2026-08-09 00:00 |
09:33:39.11 |
-49:02:46.1 |
HIP 46914 |
2.62 |
| 2026-08-09 12:00 |
09:33:46.92 |
-49:02:57.1 |
HIP 46914 |
2.67 |
| 2026-08-10 00:00 |
09:33:54.72 |
-49:03:08.7 |
HIP 46914 |
3.29 |
| 2026-08-10 12:00 |
09:34:02.53 |
-49:03:21.0 |
HIP 46914 |
4.24 |
| 2026-08-11 00:00 |
09:34:10.35 |
-49:03:33.9 |
HIP 46914 |
5.34 |
| 2026-08-11 12:00 |
09:34:18.16 |
-49:03:47.5 |
HIP 46914 |
6.52 |
| 2026-08-12 00:00 |
09:34:25.97 |
-49:04:01.8 |
HIP 46914 |
7.74 |
| 2026-08-12 12:00 |
09:34:33.79 |
-49:04:16.7 |
HIP 47048 |
7.86 |
| 2026-08-13 00:00 |
09:34:41.60 |
-49:04:32.2 |
HIP 47048 |
6.61 |
| 2026-08-13 12:00 |
09:34:49.42 |
-49:04:48.4 |
HIP 47048 |
5.38 |
| 2026-08-14 00:00 |
09:34:57.23 |
-49:05:05.3 |
HIP 47048 |
4.19 |
| 2026-08-14 12:00 |
09:35:05.04 |
-49:05:22.8 |
HIP 47048 |
3.09 |
| 2026-08-15 00:00 |
09:35:12.84 |
-49:05:40.9 |
HIP 47048 |
2.23 |
| 2026-08-15 12:00 |
09:35:20.65 |
-49:05:59.7 |
HIP 47048 |
1.94 |
| 2026-08-16 00:00 |
09:35:28.45 |
-49:06:19.1 |
HIP 47048 |
2.44 |
| 2026-08-16 12:00 |
09:35:36.24 |
-49:06:39.1 |
HIP 47048 |
3.41 |
| 2026-08-17 00:00 |
09:35:44.03 |
-49:06:59.8 |
HIP 47048 |
4.55 |
| 2026-08-17 12:00 |
09:35:51.82 |
-49:07:21.1 |
HIP 47048 |
5.77 |
| 2026-08-18 00:00 |
09:35:59.60 |
-49:07:43.1 |
HIP 47048 |
7.02 |
| 2026-08-18 12:00 |
09:36:07.37 |
-49:08:05.7 |
HIP 47048 |
8.30 |
| 2026-08-19 00:00 |
09:36:15.14 |
-49:08:28.9 |
HIP 47048 |
9.59 |