19P/Borrelly
| Parameter |
Value |
| Designation |
19P/Borrelly |
| Type |
P |
| Perihelion (tp_cal, UTC) |
2022-02-01T18:20:14.879040Z |
| Orbit solution date (soln_date, UTC) |
2024-12-30T09:03:27Z |
| Obs used |
2452 |
| NEO |
- |
| M1 |
9.800 |
| K1 |
14.500 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2021-03-06.0000000 |
| e |
0.63791428 |
| q (au) |
1.306030 |
| a (au) |
3.606965 |
| i (deg) |
29.318662 |
| Ω (om, deg) |
74.300843 |
| ω (w, deg) |
351.861606 |
| M (ma, deg) |
312.122920 |
Magnitude
Scatter + Global Linear
$$
M_a = (9.210 + 6.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
9.210 |
| n |
6.000 |
| gf |
0.800 |
| gb |
-0.962 |
| k |
0.999 |
| 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 |
| 2021-02-02 |
2021-06-23 |
-90.1795 |
+39.185 |
| 2021-06-23 |
2022-02-01 |
+6.1948 |
-1.687 |
| 2022-02-01 |
2022-05-18 |
-2.2961 |
-0.439 |
| 2022-05-18 |
2024-05-02 |
+2.9729 |
-2.179 |
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 |
17:27:23.31 |
-23:34:44.6 |
HIP 85541 |
21.91 |
| 2026-02-03 12:00 |
17:27:40.72 |
-23:35:34.0 |
HIP 85541 |
18.66 |
| 2026-02-04 00:00 |
17:27:58.04 |
-23:36:23.3 |
HIP 85541 |
15.81 |
| 2026-02-04 12:00 |
17:28:15.26 |
-23:37:12.5 |
HIP 85541 |
13.60 |
| 2026-02-05 00:00 |
17:28:32.38 |
-23:38:01.6 |
HIP 85541 |
12.35 |
| 2026-02-05 12:00 |
17:28:49.40 |
-23:38:50.6 |
HIP 85561 |
11.99 |
| 2026-02-06 00:00 |
17:29:06.32 |
-23:39:39.5 |
HIP 85561 |
10.50 |
| 2026-02-06 12:00 |
17:29:23.13 |
-23:40:28.3 |
HIP 85561 |
10.39 |
| 2026-02-07 00:00 |
17:29:39.85 |
-23:41:17.0 |
HIP 85561 |
11.67 |
| 2026-02-07 12:00 |
17:29:56.46 |
-23:42:05.6 |
HIP 85561 |
13.94 |
| 2026-02-08 00:00 |
17:30:12.96 |
-23:42:54.1 |
HIP 85703 |
11.31 |
| 2026-02-08 12:00 |
17:30:29.36 |
-23:43:42.5 |
HIP 85703 |
8.22 |
| 2026-02-09 00:00 |
17:30:45.66 |
-23:44:30.8 |
HIP 85703 |
6.05 |
| 2026-02-09 12:00 |
17:31:01.84 |
-23:45:19.1 |
HIP 85703 |
5.88 |
| 2026-02-10 00:00 |
17:31:17.91 |
-23:46:07.2 |
HIP 85703 |
7.81 |
| 2026-02-10 12:00 |
17:31:33.88 |
-23:46:55.3 |
HIP 85703 |
10.74 |
| 2026-02-11 00:00 |
17:31:49.73 |
-23:47:43.3 |
HIP 85755 |
11.52 |
| 2026-02-11 12:00 |
17:32:05.47 |
-23:48:31.3 |
HIP 85755 |
13.08 |
| 2026-02-12 00:00 |
17:32:21.10 |
-23:49:19.1 |
HIP 85755 |
15.36 |
| 2026-02-12 12:00 |
17:32:36.61 |
-23:50:06.9 |
HIP 85755 |
18.07 |
| 2026-02-13 00:00 |
17:32:52.01 |
-23:50:54.7 |
HIP 85920 |
15.83 |
| 2026-02-13 12:00 |
17:33:07.29 |
-23:51:42.3 |
HIP 85920 |
13.53 |
| 2026-02-14 00:00 |
17:33:22.45 |
-23:52:29.9 |
HIP 85920 |
11.89 |
| 2026-02-14 12:00 |
17:33:37.50 |
-23:53:17.4 |
HIP 85920 |
11.16 |
| 2026-02-15 00:00 |
17:33:52.42 |
-23:54:04.9 |
HIP 85920 |
11.51 |
| 2026-02-15 12:00 |
17:34:07.22 |
-23:54:52.3 |
HIP 85920 |
12.83 |
| 2026-02-16 00:00 |
17:34:21.90 |
-23:55:39.7 |
HIP 85920 |
14.83 |
| 2026-02-16 12:00 |
17:34:36.46 |
-23:56:27.0 |
HIP 85920 |
17.27 |
| 2026-02-17 00:00 |
17:34:50.89 |
-23:57:14.3 |
HIP 85920 |
19.97 |
| 2026-02-17 12:00 |
17:35:05.20 |
-23:58:01.5 |
HIP 86082 |
21.64 |
| 2026-02-18 00:00 |
17:35:19.37 |
-23:58:48.7 |
HIP 86082 |
21.74 |
| 2026-02-18 12:00 |
17:35:33.43 |
-23:59:35.8 |
HIP 86082 |
22.35 |
| 2026-02-19 00:00 |
17:35:47.35 |
-24:00:22.9 |
HIP 86082 |
23.41 |
| 2026-02-19 12:00 |
17:36:01.14 |
-24:01:09.9 |
HIP 86082 |
24.85 |
| 2026-02-20 00:00 |
17:36:14.80 |
-24:01:57.0 |
HIP 86082 |
26.60 |
| 2026-02-20 12:00 |
17:36:28.34 |
-24:02:44.0 |
HIP 86082 |
28.59 |
| 2026-02-21 00:00 |
17:36:41.73 |
-24:03:30.9 |
HIP 86082 |
30.77 |
| 2026-02-21 12:00 |
17:36:55.00 |
-24:04:17.9 |
HIP 86226 |
31.67 |
| 2026-02-22 00:00 |
17:37:08.13 |
-24:05:04.8 |
HIP 86226 |
30.58 |
| 2026-02-22 12:00 |
17:37:21.12 |
-24:05:51.7 |
HIP 86226 |
29.76 |
| 2026-02-23 00:00 |
17:37:33.98 |
-24:06:38.5 |
HIP 86226 |
29.24 |
| 2026-02-23 12:00 |
17:37:46.69 |
-24:07:25.4 |
HIP 86226 |
29.03 |
| 2026-02-24 00:00 |
17:37:59.27 |
-24:08:12.2 |
HIP 86226 |
29.11 |