110P/Hartley 3
| Parameter |
Value |
| Designation |
110P/Hartley 3 |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2014-12-16T16:15:29.649600Z |
| Orbit solution date (soln_date, UTC) |
2023-05-22T13:49:16Z |
| Obs used |
2416 |
| NEO |
- |
| M1 |
4.300 |
| K1 |
26.750 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2018-05-08.0000000 |
| e |
0.31628027 |
| q (au) |
2.464450 |
| a (au) |
3.604474 |
| i (deg) |
11.698362 |
| Ω (om, deg) |
287.529573 |
| ω (w, deg) |
167.395612 |
| M (ma, deg) |
178.350762 |
Magnitude
Scatter + Global Linear
$$
M_a = (8.184 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
8.184 |
| 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 |
| 2019-07-25 |
2021-01-23 |
+35.2820 |
-14.426 |
| 2021-01-23 |
2023-05-13 |
-10.1067 |
+6.783 |
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 |
20:18:27.84 |
-17:22:20.3 |
HIP 100047 |
9.95 |
| 2026-02-03 12:00 |
20:18:57.84 |
-17:20:12.6 |
HIP 100231 |
14.09 |
| 2026-02-04 00:00 |
20:19:27.81 |
-17:18:04.5 |
HIP 100231 |
11.78 |
| 2026-02-04 12:00 |
20:19:57.75 |
-17:15:56.0 |
HIP 100231 |
13.80 |
| 2026-02-05 00:00 |
20:20:27.67 |
-17:13:47.2 |
HIP 100373 |
13.40 |
| 2026-02-05 12:00 |
20:20:57.56 |
-17:11:38.1 |
HIP 100373 |
6.27 |
| 2026-02-06 00:00 |
20:21:27.42 |
-17:09:28.6 |
HIP 100373 |
3.21 |
| 2026-02-06 12:00 |
20:21:57.24 |
-17:07:18.7 |
HIP 100373 |
9.60 |
| 2026-02-07 00:00 |
20:22:27.04 |
-17:05:08.5 |
HIP 100373 |
16.88 |
| 2026-02-07 12:00 |
20:22:56.81 |
-17:02:58.0 |
HIP 100445 |
19.43 |
| 2026-02-08 00:00 |
20:23:26.54 |
-17:00:47.1 |
HIP 100650 |
15.57 |
| 2026-02-08 12:00 |
20:23:56.24 |
-16:58:35.9 |
HIP 100650 |
8.72 |
| 2026-02-09 00:00 |
20:24:25.91 |
-16:56:24.4 |
HIP 100650 |
4.46 |
| 2026-02-09 12:00 |
20:24:55.54 |
-16:54:12.5 |
HIP 100650 |
8.61 |
| 2026-02-10 00:00 |
20:25:25.14 |
-16:52:00.3 |
HIP 100650 |
15.43 |
| 2026-02-10 12:00 |
20:25:54.70 |
-16:49:47.8 |
HIP 100650 |
22.63 |
| 2026-02-11 00:00 |
20:26:24.23 |
-16:47:34.9 |
HIP 100730 |
29.92 |
| 2026-02-11 12:00 |
20:26:53.72 |
-16:45:21.7 |
HIP 100730 |
32.50 |
| 2026-02-12 00:00 |
20:27:23.17 |
-16:43:08.2 |
HIP 100730 |
36.43 |
| 2026-02-12 12:00 |
20:27:52.58 |
-16:40:54.4 |
HIP 100975 |
39.82 |
| 2026-02-13 00:00 |
20:28:21.95 |
-16:38:40.3 |
HIP 101190 |
33.47 |
| 2026-02-13 12:00 |
20:28:51.29 |
-16:36:25.9 |
HIP 101190 |
26.19 |
| 2026-02-14 00:00 |
20:29:20.58 |
-16:34:11.2 |
HIP 101190 |
18.98 |
| 2026-02-14 12:00 |
20:29:49.83 |
-16:31:56.2 |
HIP 101190 |
11.99 |
| 2026-02-15 00:00 |
20:30:19.04 |
-16:29:40.9 |
HIP 101190 |
5.98 |
| 2026-02-15 12:00 |
20:30:48.20 |
-16:27:25.2 |
HIP 101190 |
5.98 |
| 2026-02-16 00:00 |
20:31:17.32 |
-16:25:09.4 |
HIP 101190 |
11.99 |
| 2026-02-16 12:00 |
20:31:46.40 |
-16:22:53.2 |
HIP 101357 |
17.45 |
| 2026-02-17 00:00 |
20:32:15.43 |
-16:20:36.7 |
HIP 101357 |
16.42 |
| 2026-02-17 12:00 |
20:32:44.41 |
-16:18:20.0 |
HIP 101409 |
17.47 |
| 2026-02-18 00:00 |
20:33:13.35 |
-16:16:03.0 |
HIP 101409 |
14.63 |
| 2026-02-18 12:00 |
20:33:42.24 |
-16:13:45.7 |
HIP 101409 |
15.16 |
| 2026-02-19 00:00 |
20:34:11.08 |
-16:11:28.1 |
HIP 101409 |
18.75 |
| 2026-02-19 12:00 |
20:34:39.86 |
-16:09:10.3 |
HIP 101555 |
21.47 |
| 2026-02-20 00:00 |
20:35:08.60 |
-16:06:52.3 |
HIP 101555 |
19.55 |
| 2026-02-20 12:00 |
20:35:37.29 |
-16:04:34.0 |
HIP 101555 |
20.22 |
| 2026-02-21 00:00 |
20:36:05.93 |
-16:02:15.4 |
HIP 101555 |
23.26 |
| 2026-02-21 12:00 |
20:36:34.51 |
-15:59:56.6 |
HIP 101555 |
27.89 |
| 2026-02-22 00:00 |
20:37:03.04 |
-15:57:37.6 |
HIP 101555 |
33.46 |
| 2026-02-22 12:00 |
20:37:31.52 |
-15:55:18.3 |
HIP 101740 |
38.84 |
| 2026-02-23 00:00 |
20:37:59.94 |
-15:52:58.8 |
HIP 102026 |
39.43 |
| 2026-02-23 12:00 |
20:38:28.30 |
-15:50:39.0 |
HIP 102026 |
34.27 |
| 2026-02-24 00:00 |
20:38:56.61 |
-15:48:19.1 |
HIP 102026 |
29.97 |