| Parameter |
Value |
| Designation |
119P/Parker-Hartley |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2014-04-03T23:02:16.448640Z |
| Orbit solution date (soln_date, UTC) |
2024-09-01T19:42:26Z |
| Obs used |
3237 |
| NEO |
- |
| M1 |
9.600 |
| K1 |
13.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-08-20.0000000 |
| e |
0.29594027 |
| q (au) |
3.023931 |
| a (au) |
4.294992 |
| i (deg) |
5.183509 |
| Ω (om, deg) |
243.678154 |
| ω (w, deg) |
181.859700 |
| M (ma, deg) |
55.701021 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.651 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.651 |
| n |
6.000 |
| gf |
0.801 |
| gb |
-0.500 |
| k |
0.964 |
| δ90 |
1.000 |
| 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 |
| 2021-05-28 |
2021-10-23 |
+0.9742 |
-0.715 |
| 2021-10-23 |
2024-05-06 |
-1.5544 |
+0.897 |
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 |
16:06:26.25 |
-16:25:41.6 |
HIP 78941 |
18.12 |
| 2026-07-29 12:00 |
16:06:22.95 |
-16:26:10.4 |
HIP 78941 |
18.86 |
| 2026-07-30 00:00 |
16:06:19.85 |
-16:26:39.8 |
HIP 78941 |
19.60 |
| 2026-07-30 12:00 |
16:06:16.94 |
-16:27:09.7 |
HIP 78941 |
20.35 |
| 2026-07-31 00:00 |
16:06:14.22 |
-16:27:40.1 |
HIP 78941 |
21.09 |
| 2026-07-31 12:00 |
16:06:11.70 |
-16:28:11.1 |
HIP 78941 |
21.82 |
| 2026-08-01 00:00 |
16:06:09.38 |
-16:28:42.6 |
HIP 79015 |
22.33 |
| 2026-08-01 12:00 |
16:06:07.25 |
-16:29:14.6 |
HIP 79015 |
22.79 |
| 2026-08-02 00:00 |
16:06:05.32 |
-16:29:47.2 |
HIP 79015 |
23.21 |
| 2026-08-02 12:00 |
16:06:03.58 |
-16:30:20.3 |
HIP 79015 |
23.61 |
| 2026-08-03 00:00 |
16:06:02.04 |
-16:30:53.9 |
HIP 79015 |
23.97 |
| 2026-08-03 12:00 |
16:06:00.70 |
-16:31:28.0 |
HIP 79015 |
24.30 |
| 2026-08-04 00:00 |
16:05:59.55 |
-16:32:02.7 |
HIP 79015 |
24.59 |
| 2026-08-04 12:00 |
16:05:58.59 |
-16:32:37.9 |
HIP 79015 |
24.85 |
| 2026-08-05 00:00 |
16:05:57.83 |
-16:33:13.5 |
HIP 79015 |
25.08 |
| 2026-08-05 12:00 |
16:05:57.26 |
-16:33:49.7 |
HIP 79015 |
25.28 |
| 2026-08-06 00:00 |
16:05:56.90 |
-16:34:26.5 |
HIP 79015 |
25.44 |
| 2026-08-06 12:00 |
16:05:56.72 |
-16:35:03.7 |
HIP 78755 |
25.10 |
| 2026-08-07 00:00 |
16:05:56.74 |
-16:35:41.4 |
HIP 78755 |
24.65 |
| 2026-08-07 12:00 |
16:05:56.96 |
-16:36:19.6 |
HIP 78755 |
24.25 |
| 2026-08-08 00:00 |
16:05:57.36 |
-16:36:58.4 |
HIP 78755 |
23.88 |
| 2026-08-08 12:00 |
16:05:57.97 |
-16:37:37.6 |
HIP 78755 |
23.55 |
| 2026-08-09 00:00 |
16:05:58.77 |
-16:38:17.3 |
HIP 78755 |
23.27 |
| 2026-08-09 12:00 |
16:05:59.76 |
-16:38:57.6 |
HIP 78755 |
23.04 |
| 2026-08-10 00:00 |
16:06:00.95 |
-16:39:38.3 |
HIP 78956 |
22.81 |
| 2026-08-10 12:00 |
16:06:02.33 |
-16:40:19.5 |
HIP 78956 |
22.08 |
| 2026-08-11 00:00 |
16:06:03.90 |
-16:41:01.2 |
HIP 78956 |
21.31 |
| 2026-08-11 12:00 |
16:06:05.67 |
-16:41:43.3 |
HIP 78956 |
20.51 |
| 2026-08-12 00:00 |
16:06:07.64 |
-16:42:26.0 |
HIP 78956 |
19.67 |
| 2026-08-12 12:00 |
16:06:09.79 |
-16:43:09.1 |
HIP 78956 |
18.79 |
| 2026-08-13 00:00 |
16:06:12.14 |
-16:43:52.7 |
HIP 78956 |
17.88 |
| 2026-08-13 12:00 |
16:06:14.68 |
-16:44:36.8 |
HIP 78956 |
16.93 |
| 2026-08-14 00:00 |
16:06:17.41 |
-16:45:21.3 |
HIP 78956 |
15.94 |
| 2026-08-14 12:00 |
16:06:20.33 |
-16:46:06.3 |
HIP 78956 |
14.92 |
| 2026-08-15 00:00 |
16:06:23.45 |
-16:46:51.7 |
HIP 78956 |
13.86 |
| 2026-08-15 12:00 |
16:06:26.75 |
-16:47:37.6 |
HIP 78956 |
12.76 |
| 2026-08-16 00:00 |
16:06:30.24 |
-16:48:23.9 |
HIP 78956 |
11.62 |
| 2026-08-16 12:00 |
16:06:33.93 |
-16:49:10.7 |
HIP 78956 |
10.45 |
| 2026-08-17 00:00 |
16:06:37.80 |
-16:49:57.9 |
HIP 78956 |
9.23 |
| 2026-08-17 12:00 |
16:06:41.86 |
-16:50:45.6 |
HIP 78956 |
7.99 |
| 2026-08-18 00:00 |
16:06:46.11 |
-16:51:33.7 |
HIP 78956 |
6.71 |
| 2026-08-18 12:00 |
16:06:50.54 |
-16:52:22.2 |
HIP 78956 |
5.41 |
| 2026-08-19 00:00 |
16:06:55.16 |
-16:53:11.1 |
HIP 78956 |
4.10 |