| 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 |
+16.0709 |
-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) |
| 2026-05-12 00:00 |
23:34:05.89 |
-11:24:58.6 |
HIP 116398 |
18.88 |
| 2026-05-12 12:00 |
23:34:08.53 |
-11:24:49.4 |
HIP 116398 |
18.41 |
| 2026-05-13 00:00 |
23:34:11.14 |
-11:24:40.5 |
HIP 116398 |
17.95 |
| 2026-05-13 12:00 |
23:34:13.73 |
-11:24:31.8 |
HIP 116398 |
17.51 |
| 2026-05-14 00:00 |
23:34:16.28 |
-11:24:23.4 |
HIP 116398 |
17.09 |
| 2026-05-14 12:00 |
23:34:18.80 |
-11:24:15.2 |
HIP 116398 |
16.68 |
| 2026-05-15 00:00 |
23:34:21.29 |
-11:24:07.3 |
HIP 116398 |
16.30 |
| 2026-05-15 12:00 |
23:34:23.75 |
-11:23:59.6 |
HIP 116398 |
15.93 |
| 2026-05-16 00:00 |
23:34:26.17 |
-11:23:52.1 |
HIP 116398 |
15.58 |
| 2026-05-16 12:00 |
23:34:28.57 |
-11:23:44.9 |
HIP 116398 |
15.25 |
| 2026-05-17 00:00 |
23:34:30.93 |
-11:23:37.9 |
HIP 116398 |
14.93 |
| 2026-05-17 12:00 |
23:34:33.26 |
-11:23:31.2 |
HIP 116398 |
14.64 |
| 2026-05-18 00:00 |
23:34:35.56 |
-11:23:24.7 |
HIP 116398 |
14.37 |
| 2026-05-18 12:00 |
23:34:37.82 |
-11:23:18.5 |
HIP 116398 |
14.11 |
| 2026-05-19 00:00 |
23:34:40.05 |
-11:23:12.5 |
HIP 116398 |
13.88 |
| 2026-05-19 12:00 |
23:34:42.25 |
-11:23:06.7 |
HIP 116398 |
13.66 |
| 2026-05-20 00:00 |
23:34:44.42 |
-11:23:01.3 |
HIP 116398 |
13.46 |
| 2026-05-20 12:00 |
23:34:46.55 |
-11:22:56.0 |
HIP 116398 |
13.28 |
| 2026-05-21 00:00 |
23:34:48.65 |
-11:22:51.0 |
HIP 116398 |
13.13 |
| 2026-05-21 12:00 |
23:34:50.71 |
-11:22:46.3 |
HIP 116398 |
12.98 |
| 2026-05-22 00:00 |
23:34:52.74 |
-11:22:41.8 |
HIP 116398 |
12.86 |
| 2026-05-22 12:00 |
23:34:54.74 |
-11:22:37.5 |
HIP 116398 |
12.76 |
| 2026-05-23 00:00 |
23:34:56.71 |
-11:22:33.5 |
HIP 116398 |
12.67 |
| 2026-05-23 12:00 |
23:34:58.64 |
-11:22:29.8 |
HIP 116398 |
12.60 |
| 2026-05-24 00:00 |
23:35:00.53 |
-11:22:26.2 |
HIP 116398 |
12.54 |
| 2026-05-24 12:00 |
23:35:02.40 |
-11:22:23.0 |
HIP 116398 |
12.50 |
| 2026-05-25 00:00 |
23:35:04.23 |
-11:22:20.0 |
HIP 116398 |
12.47 |
| 2026-05-25 12:00 |
23:35:06.02 |
-11:22:17.2 |
HIP 116398 |
12.46 |
| 2026-05-26 00:00 |
23:35:07.78 |
-11:22:14.7 |
HIP 116398 |
12.46 |
| 2026-05-26 12:00 |
23:35:09.50 |
-11:22:12.4 |
HIP 116398 |
12.47 |
| 2026-05-27 00:00 |
23:35:11.20 |
-11:22:10.4 |
HIP 116398 |
12.49 |
| 2026-05-27 12:00 |
23:35:12.85 |
-11:22:08.6 |
HIP 116398 |
12.52 |
| 2026-05-28 00:00 |
23:35:14.47 |
-11:22:07.1 |
HIP 116398 |
12.55 |
| 2026-05-28 12:00 |
23:35:16.06 |
-11:22:05.8 |
HIP 116398 |
12.60 |
| 2026-05-29 00:00 |
23:35:17.61 |
-11:22:04.7 |
HIP 116398 |
12.65 |
| 2026-05-29 12:00 |
23:35:19.13 |
-11:22:03.9 |
HIP 116398 |
12.71 |
| 2026-05-30 00:00 |
23:35:20.61 |
-11:22:03.4 |
HIP 116398 |
12.78 |
| 2026-05-30 12:00 |
23:35:22.06 |
-11:22:03.1 |
HIP 116398 |
12.84 |
| 2026-05-31 00:00 |
23:35:23.47 |
-11:22:03.1 |
HIP 116398 |
12.91 |
| 2026-05-31 12:00 |
23:35:24.84 |
-11:22:03.2 |
HIP 116398 |
12.99 |
| 2026-06-01 00:00 |
23:35:26.18 |
-11:22:03.7 |
HIP 116398 |
13.06 |
| 2026-06-01 12:00 |
23:35:27.49 |
-11:22:04.4 |
HIP 116398 |
13.14 |
| 2026-06-02 00:00 |
23:35:28.76 |
-11:22:05.3 |
HIP 116398 |
13.22 |