C/2015 V1 (PANSTARRS)
| Parameter |
Value |
| Designation |
C/2015 V1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2017-12-17T19:17:15.800640Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:16Z |
| Obs used |
2145 |
| NEO |
- |
| M1 |
8.300 |
| K1 |
8.000 |
| PC |
0.030 |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2017-06-28.0000000 |
| e |
1.00055464 |
| q (au) |
4.266704 |
| a (au) |
-7692.742203 |
| i (deg) |
139.230487 |
| Ω (om, deg) |
197.193756 |
| ω (w, deg) |
179.649665 |
| M (ma, deg) |
-0.000252 |
Magnitude
Scatter + Global Linear
$$
M_a = (10.399 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
10.399 |
| n |
2.000 |
| gf |
0.821 |
| gb |
-0.500 |
| k |
0.901 |
| 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 |
| 2015-11-02 |
2016-09-21 |
+10.7844 |
-8.539 |
| 2016-09-21 |
2017-03-03 |
+2.3776 |
-2.080 |
| 2017-03-03 |
2017-12-17 |
-9.8282 |
+6.267 |
| 2017-12-17 |
2019-06-11 |
+7.0878 |
-4.329 |
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 |
15:57:14.71 |
-53:30:41.5 |
HIP 78294 |
19.56 |
| 2026-02-03 12:00 |
15:57:16.44 |
-53:31:25.4 |
HIP 78294 |
19.02 |
| 2026-02-04 00:00 |
15:57:18.10 |
-53:32:09.3 |
HIP 78294 |
18.50 |
| 2026-02-04 12:00 |
15:57:19.67 |
-53:32:53.3 |
HIP 78294 |
18.02 |
| 2026-02-05 00:00 |
15:57:21.17 |
-53:33:37.2 |
HIP 78294 |
17.57 |
| 2026-02-05 12:00 |
15:57:22.58 |
-53:34:21.2 |
HIP 78294 |
17.15 |
| 2026-02-06 00:00 |
15:57:23.90 |
-53:35:05.1 |
HIP 78294 |
16.77 |
| 2026-02-06 12:00 |
15:57:25.14 |
-53:35:49.1 |
HIP 78294 |
16.42 |
| 2026-02-07 00:00 |
15:57:26.30 |
-53:36:33.0 |
HIP 78294 |
16.12 |
| 2026-02-07 12:00 |
15:57:27.38 |
-53:37:17.0 |
HIP 78294 |
15.86 |
| 2026-02-08 00:00 |
15:57:28.37 |
-53:38:00.9 |
HIP 78294 |
15.64 |
| 2026-02-08 12:00 |
15:57:29.28 |
-53:38:44.8 |
HIP 78294 |
15.47 |
| 2026-02-09 00:00 |
15:57:30.10 |
-53:39:28.7 |
HIP 78294 |
15.35 |
| 2026-02-09 12:00 |
15:57:30.84 |
-53:40:12.6 |
HIP 78294 |
15.27 |
| 2026-02-10 00:00 |
15:57:31.49 |
-53:40:56.5 |
HIP 78294 |
15.25 |
| 2026-02-10 12:00 |
15:57:32.05 |
-53:41:40.3 |
HIP 78294 |
15.27 |
| 2026-02-11 00:00 |
15:57:32.53 |
-53:42:24.1 |
HIP 78294 |
15.33 |
| 2026-02-11 12:00 |
15:57:32.92 |
-53:43:07.8 |
HIP 78294 |
15.45 |
| 2026-02-12 00:00 |
15:57:33.23 |
-53:43:51.5 |
HIP 78294 |
15.61 |
| 2026-02-12 12:00 |
15:57:33.45 |
-53:44:35.2 |
HIP 78294 |
15.81 |
| 2026-02-13 00:00 |
15:57:33.58 |
-53:45:18.8 |
HIP 78294 |
16.06 |
| 2026-02-13 12:00 |
15:57:33.62 |
-53:46:02.3 |
HIP 78294 |
16.35 |
| 2026-02-14 00:00 |
15:57:33.58 |
-53:46:45.8 |
HIP 78294 |
16.67 |
| 2026-02-14 12:00 |
15:57:33.44 |
-53:47:29.3 |
HIP 78294 |
17.03 |
| 2026-02-15 00:00 |
15:57:33.22 |
-53:48:12.7 |
HIP 78294 |
17.42 |
| 2026-02-15 12:00 |
15:57:32.91 |
-53:48:56.0 |
HIP 78294 |
17.85 |
| 2026-02-16 00:00 |
15:57:32.51 |
-53:49:39.2 |
HIP 78294 |
18.30 |
| 2026-02-16 12:00 |
15:57:32.03 |
-53:50:22.3 |
HIP 78294 |
18.78 |
| 2026-02-17 00:00 |
15:57:31.45 |
-53:51:05.4 |
HIP 78294 |
19.28 |
| 2026-02-17 12:00 |
15:57:30.78 |
-53:51:48.4 |
HIP 78294 |
19.81 |
| 2026-02-18 00:00 |
15:57:30.03 |
-53:52:31.2 |
HIP 78294 |
20.36 |
| 2026-02-18 12:00 |
15:57:29.18 |
-53:53:14.0 |
HIP 78294 |
20.92 |
| 2026-02-19 00:00 |
15:57:28.25 |
-53:53:56.7 |
HIP 78294 |
21.51 |
| 2026-02-19 12:00 |
15:57:27.22 |
-53:54:39.3 |
HIP 78294 |
22.11 |
| 2026-02-20 00:00 |
15:57:26.10 |
-53:55:21.8 |
HIP 78355 |
22.55 |
| 2026-02-20 12:00 |
15:57:24.90 |
-53:56:04.1 |
HIP 78355 |
22.55 |
| 2026-02-21 00:00 |
15:57:23.60 |
-53:56:46.4 |
HIP 78355 |
22.58 |
| 2026-02-21 12:00 |
15:57:22.21 |
-53:57:28.5 |
HIP 78145 |
22.46 |
| 2026-02-22 00:00 |
15:57:20.74 |
-53:58:10.5 |
HIP 78145 |
21.77 |
| 2026-02-22 12:00 |
15:57:19.17 |
-53:58:52.4 |
HIP 78145 |
21.08 |
| 2026-02-23 00:00 |
15:57:17.51 |
-53:59:34.1 |
HIP 78145 |
20.39 |
| 2026-02-23 12:00 |
15:57:15.76 |
-54:00:15.7 |
HIP 78145 |
19.72 |
| 2026-02-24 00:00 |
15:57:13.92 |
-54:00:57.2 |
HIP 78145 |
19.05 |