20312+0513 AG  257

 
 
20h 31m 13.51s +05 13' 08.7" P.A. 75.30 sep 1.6 mag 9.49,9.77 Sp K0 dist. 48.54 pc (158.34 l.y.)
 
 
Coord 2000
20312+0513
Discov num
AG  257
Comp
Coord arcsec 2000
20 31 13.51 +05 13 08.7
Date first
1902
Date last
2016
Obs
45
Pa first
55
Pa last
75
P.A. Now (θ)
75.3°
Sep first
1.6
Sep last
1.7
Sep. Now (ρ)
1.64"
Mag pri
9.49
Mag sec
9.77
delta mag (ΔM)
0.28
Spectral class
K0 (yellow-orange)
Pri motion ra
+303
Sec motion ra
+303
Pri motion dec
+275
Sec motion dec
+275
Notes
N O (See Notes, Orbital solution)
Visually invisible, K-band or other infrared star This double is physical.
 
 
OTHER CATALOGS AND DESIGNATIONS
 
 
Precise pa
75
Precise sep
1.687
Constellation
Delphinus
HIP
101236
Tycho2
0518-01755-1
Gaia DR2
76226458752
HD
195434
BD
BD+04 4470
Distance
48.54
Distance ly
158.34
last precise pa
75
last precise sep
1.687
 
 
ORBITAL ELEMENTS
 
 
Period (P)676.2405y± 293.8216 Periastron (T)1836.3877y± 38.3978 Semi-major axis (a)2.50711a± 1.08477
Eccentricity (e)0.62797± 0.28087 Inclination (i)75.379°± 8.433 Longitude of periastron (ω)272.461°± 20.931
Node (Ω)46.399°± 9.075 Note Grade5(1=Definitive, 9=Indet.)
Equinox Last observation2015
label rho theta
2000 1.746 70.7
2001 1.741 70.9
2002 1.736 71.1
2003 1.731 71.4
2004 1.725 71.6
2005 1.720 71.8
2006 1.715 72.0
2007 1.709 72.3
2008 1.704 72.5
2009 1.698 72.7
2010 1.693 72.9
2011 1.687 73.2
2012 1.682 73.4
2013 1.676 73.6
2014 1.671 73.9
2015 1.665 74.1
2016 1.660 74.3
2017 1.654 74.6
2018 1.648 74.8
2019 1.642 75.1
2020 1.637 75.3
2021 1.631 75.6
2022 1.625 75.8
2023 1.619 76.1
2024 1.613 76.3
2025 1.607 76.6
2026 1.602 76.8
2027 1.596 77.1
2028 1.590 77.3
2029 1.584 77.6
2030 1.578 77.9

Note: Theta is PA, Rho is Sep. For yearly orbits, data refer to Jan 1st.
 
grafico orbita






wds20312%2B0513b.png orbit plot
Measures: green=micrometric, blue=interferometric, purple=photographic
 
 
 
WDS HISTORIC DATA
 
 
coord_2000 discov_num comp epoch obs pa sep mag_pri mag_sec spectr notes coord_arcsec_2000
20312+0513 AG 257 1999 36 70 1.7 9.49 9.77 K0 D 203113.51+051308.7
20312+0513 AG 257 2008 37 73 1.7 9.49 9.77 K0 D 203113.51+051308.7
20312+0513 AG 257 2009 44 73 1.7 9.49 9.77 K0 D 203113.51+051308.7
20312+0513 AG 257 2015 42 75 1.7 9.49 9.77 K0 NO 203113.51+051308.7
20312+0513 AG 257 2016 43 75 1.7 9.49 9.77 K0 NO 203113.51+051308.7

If you need more information about this double, apply for a data request form to the WDS.