15P/Finlay
| Parameter |
Value |
| Designation |
15P/Finlay |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2014-12-27T01:44:35.957760Z |
| Orbit solution date (soln_date, UTC) |
2024-04-16T11:19:30Z |
| Obs used |
1655 |
| NEO |
Yes |
| M1 |
14.900 |
| K1 |
8.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-11-01.0000000 |
| e |
0.72018544 |
| q (au) |
0.976687 |
| a (au) |
3.490479 |
| i (deg) |
6.800480 |
| Ω (om, deg) |
13.753875 |
| ω (w, deg) |
347.625750 |
| M (ma, deg) |
46.690962 |
Magnitude
Scatter + Global Linear
$$
M_a = (14.416 + 5.627\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
14.416 |
| n |
5.627 |
| gf |
1.000 |
| gb |
-0.643 |
| k |
0.800 |
| 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 |
| 2021-04-10 |
2022-03-03 |
+4.0180 |
-1.591 |
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 |
13:49:07.55 |
-12:00:05.2 |
HIP 67482 |
34.24 |
| 2026-02-03 12:00 |
13:49:07.73 |
-12:00:21.4 |
HIP 67482 |
33.97 |
| 2026-02-04 00:00 |
13:49:07.72 |
-12:00:36.7 |
HIP 67482 |
33.72 |
| 2026-02-04 12:00 |
13:49:07.52 |
-12:00:50.9 |
HIP 67482 |
33.51 |
| 2026-02-05 00:00 |
13:49:07.13 |
-12:01:04.1 |
HIP 67482 |
33.32 |
| 2026-02-05 12:00 |
13:49:06.55 |
-12:01:16.3 |
HIP 67482 |
33.17 |
| 2026-02-06 00:00 |
13:49:05.77 |
-12:01:27.5 |
HIP 67482 |
33.04 |
| 2026-02-06 12:00 |
13:49:04.80 |
-12:01:37.6 |
HIP 67482 |
32.95 |
| 2026-02-07 00:00 |
13:49:03.64 |
-12:01:46.8 |
HIP 67482 |
32.89 |
| 2026-02-07 12:00 |
13:49:02.29 |
-12:01:54.9 |
HIP 67482 |
32.87 |
| 2026-02-08 00:00 |
13:49:00.74 |
-12:02:01.9 |
HIP 67482 |
32.88 |
| 2026-02-08 12:00 |
13:48:58.99 |
-12:02:07.9 |
HIP 67482 |
32.93 |
| 2026-02-09 00:00 |
13:48:57.05 |
-12:02:12.9 |
HIP 67482 |
33.01 |
| 2026-02-09 12:00 |
13:48:54.91 |
-12:02:16.8 |
HIP 67482 |
33.14 |
| 2026-02-10 00:00 |
13:48:52.58 |
-12:02:19.7 |
HIP 67482 |
33.31 |
| 2026-02-10 12:00 |
13:48:50.05 |
-12:02:21.5 |
HIP 67482 |
33.52 |
| 2026-02-11 00:00 |
13:48:47.32 |
-12:02:22.3 |
HIP 67482 |
33.79 |
| 2026-02-11 12:00 |
13:48:44.39 |
-12:02:22.0 |
HIP 67482 |
34.09 |
| 2026-02-12 00:00 |
13:48:41.27 |
-12:02:20.6 |
HIP 67482 |
34.45 |
| 2026-02-12 12:00 |
13:48:37.94 |
-12:02:18.2 |
HIP 67482 |
34.86 |
| 2026-02-13 00:00 |
13:48:34.42 |
-12:02:14.7 |
HIP 67482 |
35.32 |
| 2026-02-13 12:00 |
13:48:30.69 |
-12:02:10.2 |
HIP 67482 |
35.84 |
| 2026-02-14 00:00 |
13:48:26.77 |
-12:02:04.5 |
HIP 67482 |
36.42 |
| 2026-02-14 12:00 |
13:48:22.65 |
-12:01:57.8 |
HIP 67482 |
37.05 |
| 2026-02-15 00:00 |
13:48:18.32 |
-12:01:50.0 |
HIP 67166 |
36.88 |
| 2026-02-15 12:00 |
13:48:13.80 |
-12:01:41.1 |
HIP 67166 |
35.84 |
| 2026-02-16 00:00 |
13:48:09.07 |
-12:01:31.1 |
HIP 67166 |
34.75 |
| 2026-02-16 12:00 |
13:48:04.15 |
-12:01:20.1 |
HIP 67166 |
33.63 |
| 2026-02-17 00:00 |
13:47:59.02 |
-12:01:08.0 |
HIP 67166 |
32.47 |
| 2026-02-17 12:00 |
13:47:53.69 |
-12:00:54.7 |
HIP 67166 |
31.28 |
| 2026-02-18 00:00 |
13:47:48.16 |
-12:00:40.4 |
HIP 67166 |
30.06 |
| 2026-02-18 12:00 |
13:47:42.43 |
-12:00:25.0 |
HIP 67166 |
28.81 |
| 2026-02-19 00:00 |
13:47:36.50 |
-12:00:08.5 |
HIP 67166 |
27.54 |
| 2026-02-19 12:00 |
13:47:30.37 |
-11:59:50.9 |
HIP 67166 |
26.26 |
| 2026-02-20 00:00 |
13:47:24.04 |
-11:59:32.2 |
HIP 67166 |
24.96 |
| 2026-02-20 12:00 |
13:47:17.51 |
-11:59:12.5 |
HIP 67166 |
23.66 |
| 2026-02-21 00:00 |
13:47:10.78 |
-11:58:51.6 |
HIP 67166 |
22.37 |
| 2026-02-21 12:00 |
13:47:03.84 |
-11:58:29.6 |
HIP 67166 |
21.11 |
| 2026-02-22 00:00 |
13:46:56.71 |
-11:58:06.6 |
HIP 67166 |
19.88 |
| 2026-02-22 12:00 |
13:46:49.38 |
-11:57:42.4 |
HIP 67166 |
18.73 |
| 2026-02-23 00:00 |
13:46:41.85 |
-11:57:17.2 |
HIP 67166 |
17.66 |
| 2026-02-23 12:00 |
13:46:34.13 |
-11:56:50.8 |
HIP 67166 |
16.73 |
| 2026-02-24 00:00 |
13:46:26.20 |
-11:56:23.4 |
HIP 67166 |
15.96 |