| Parameter |
Value |
| Designation |
C/2014 Y1 (PANSTARRS) |
| Type |
C |
| Perihelion (tp_cal, UTC) |
2016-01-17T15:41:20.803200Z |
| Orbit solution date (soln_date, UTC) |
2021-04-15T23:33:05Z |
| Obs used |
305 |
| NEO |
- |
| M1 |
12.800 |
| K1 |
4.500 |
| PC |
- |
Osculating Elements
| Parameter |
Value |
| Epoch (epoch_cal, TDB) |
2015-04-19.0000000 |
| e |
1.00210330 |
| q (au) |
2.240976 |
| a (au) |
-1065.459229 |
| i (deg) |
14.921289 |
| Ω (om, deg) |
19.516424 |
| ω (w, deg) |
182.265969 |
| M (ma, deg) |
-0.007755 |
Magnitude
Scatter + Global Linear
$$
M_a = (15.038 + 2.000\cdot 2.5\log_{10} r) + \epsilon - 2.5\log_{10}\Phi(\theta) + 5\log_{10}\Delta
$$
$$
\theta = 180^\circ - \alpha
$$
$$
\Phi(\theta) = \frac{\delta_{90} D(\theta) + 1}{\delta_{90} + 1},\quad D(\theta) = k\cdot \Phi_{HG}(\theta; g_f) + (1-k)\cdot \Phi_{HG}(\theta; g_b)
$$
$$
\Phi_{HG}(\theta; g) = \left(\frac{1+g^2}{1+g^2-2g\cos\theta}\right)^{3/2},\quad \Phi_{HG}(90^\circ)=1
$$
Model Parameters
| Parameter |
Value |
| H0 |
15.038 |
| n |
2.000 |
| gf |
1.000 |
| gb |
-0.719 |
| 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 |
| 2014-11-17 |
2015-04-22 |
+9.9842 |
-6.474 |
| 2015-04-22 |
2016-01-10 |
-0.5262 |
-0.311 |
| 2016-01-19 |
2016-05-29 |
+16.0710 |
-4.516 |
log10 r = log10(heliocentric distance / AU), Δ = geocentric distance (AU)
Ephemeris
| Date/Time (UTC) |
RA (J2000) |
Dec (J2000) |
Nearest HIP |
Dist from HIP (arcmin) |
| 2026-09-20 00:00 |
23:27:12.42 |
-12:33:38.9 |
HIP 115789 |
22.41 |
| 2026-09-20 12:00 |
23:27:08.22 |
-12:34:01.9 |
HIP 115789 |
22.21 |
| 2026-09-21 00:00 |
23:27:04.03 |
-12:34:24.8 |
HIP 115789 |
22.06 |
| 2026-09-21 12:00 |
23:26:59.84 |
-12:34:47.5 |
HIP 115789 |
21.97 |
| 2026-09-22 00:00 |
23:26:55.66 |
-12:35:10.1 |
HIP 115789 |
21.93 |
| 2026-09-22 12:00 |
23:26:51.48 |
-12:35:32.6 |
HIP 115629 |
21.40 |
| 2026-09-23 00:00 |
23:26:47.31 |
-12:35:54.9 |
HIP 115629 |
20.48 |
| 2026-09-23 12:00 |
23:26:43.15 |
-12:36:17.0 |
HIP 115629 |
19.58 |
| 2026-09-24 00:00 |
23:26:39.00 |
-12:36:39.1 |
HIP 115629 |
18.70 |
| 2026-09-24 12:00 |
23:26:34.85 |
-12:37:00.9 |
HIP 115629 |
17.84 |
| 2026-09-25 00:00 |
23:26:30.71 |
-12:37:22.7 |
HIP 115629 |
17.01 |
| 2026-09-25 12:00 |
23:26:26.58 |
-12:37:44.2 |
HIP 115629 |
16.20 |
| 2026-09-26 00:00 |
23:26:22.46 |
-12:38:05.6 |
HIP 115629 |
15.43 |
| 2026-09-26 12:00 |
23:26:18.35 |
-12:38:26.9 |
HIP 115629 |
14.70 |
| 2026-09-27 00:00 |
23:26:14.25 |
-12:38:48.0 |
HIP 115629 |
14.01 |
| 2026-09-27 12:00 |
23:26:10.16 |
-12:39:08.9 |
HIP 115629 |
13.37 |
| 2026-09-28 00:00 |
23:26:06.08 |
-12:39:29.7 |
HIP 115629 |
12.78 |
| 2026-09-28 12:00 |
23:26:02.01 |
-12:39:50.3 |
HIP 115629 |
12.26 |
| 2026-09-29 00:00 |
23:25:57.95 |
-12:40:10.8 |
HIP 115629 |
11.81 |
| 2026-09-29 12:00 |
23:25:53.91 |
-12:40:31.0 |
HIP 115629 |
11.43 |
| 2026-09-30 00:00 |
23:25:49.87 |
-12:40:51.2 |
HIP 115629 |
11.14 |
| 2026-09-30 12:00 |
23:25:45.85 |
-12:41:11.1 |
HIP 115629 |
10.95 |
| 2026-10-01 00:00 |
23:25:41.84 |
-12:41:30.9 |
HIP 115629 |
10.84 |
| 2026-10-01 12:00 |
23:25:37.84 |
-12:41:50.5 |
HIP 115629 |
10.83 |
| 2026-10-02 00:00 |
23:25:33.85 |
-12:42:09.9 |
HIP 115629 |
10.92 |
| 2026-10-02 12:00 |
23:25:29.88 |
-12:42:29.1 |
HIP 115629 |
11.10 |
| 2026-10-03 00:00 |
23:25:25.92 |
-12:42:48.2 |
HIP 115629 |
11.36 |
| 2026-10-03 12:00 |
23:25:21.98 |
-12:43:07.0 |
HIP 115629 |
11.71 |
| 2026-10-04 00:00 |
23:25:18.05 |
-12:43:25.7 |
HIP 115629 |
12.12 |
| 2026-10-04 12:00 |
23:25:14.13 |
-12:43:44.2 |
HIP 115629 |
12.60 |
| 2026-10-05 00:00 |
23:25:10.24 |
-12:44:02.6 |
HIP 115629 |
13.13 |
| 2026-10-05 12:00 |
23:25:06.35 |
-12:44:20.7 |
HIP 115629 |
13.72 |
| 2026-10-06 00:00 |
23:25:02.48 |
-12:44:38.6 |
HIP 115629 |
14.34 |
| 2026-10-06 12:00 |
23:24:58.63 |
-12:44:56.4 |
HIP 115629 |
15.00 |
| 2026-10-07 00:00 |
23:24:54.80 |
-12:45:13.9 |
HIP 115629 |
15.68 |
| 2026-10-07 12:00 |
23:24:50.98 |
-12:45:31.3 |
HIP 115629 |
16.39 |
| 2026-10-08 00:00 |
23:24:47.18 |
-12:45:48.5 |
HIP 115629 |
17.13 |
| 2026-10-08 12:00 |
23:24:43.40 |
-12:46:05.4 |
HIP 115629 |
17.88 |
| 2026-10-09 00:00 |
23:24:39.63 |
-12:46:22.2 |
HIP 115629 |
18.64 |
| 2026-10-09 12:00 |
23:24:35.88 |
-12:46:38.7 |
HIP 115629 |
19.42 |
| 2026-10-10 00:00 |
23:24:32.16 |
-12:46:55.1 |
HIP 115629 |
20.21 |
| 2026-10-10 12:00 |
23:24:28.45 |
-12:47:11.2 |
HIP 115629 |
21.00 |
| 2026-10-11 00:00 |
23:24:24.76 |
-12:47:27.1 |
HIP 115629 |
21.80 |