View source for Astronomy:WISE 1217+1626

{{Short description|Star in the constellation Coma Berenices}}
{{Sky|12|17|56.96|+|16|26|39.98|34.2}}
{{Starbox begin
|name=WISEPC J121756.91+162640.2
}}
{{Starbox observe
|epoch=MJD 55549.01{{r|Kirkpatrick2011}}
|equinox=[[Astronomy:J2000|J2000]]{{r|Kirkpatrick2011}}
|constell=[[Astronomy:Coma Berenices|Coma Berenices]]
|ra={{RA|12|17|56.96}}{{r|Kirkpatrick2011}}
|dec={{DEC|16|26|39.98}}{{r|Kirkpatrick2011}}
}}
{{Infobox|child=yes
 | header1 = <div style="background-color: #FFFFC0;">Characteristics</div>
 | header2 = Whole system
 | label3 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(Y ([[Astronomy:Mauna Kea Observatory|MKO]] filter system)</small>
 |  data3 = {{val|18.38|0.04}}<ref name=Liu2012/>
 | label4 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(J (2MASS filter system)</small>
 |  data4 = >18.52{{r|Kirkpatrick2011}}
 | label5 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(J ([[Astronomy:Mauna Kea Observatory|MKO]] filter system)</small>
 |  data5 = {{val|17.83|0.02}}{{r|Kirkpatrick2011|Liu2012}}
 | label6 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(H (2MASS filter system)</small>
 |  data6 = >17.50{{r|Kirkpatrick2011}}
 | label7 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(H ([[Astronomy:Mauna Kea Observatory|MKO]] filter system)</small>
 |  data7 = {{val|18.18|0.05}}{{r|Kirkpatrick2011|Liu2012}}
 | label8 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(K<sub>S</sub> (2MASS filter system)</small>
 |  data8 = >16.64{{r|Kirkpatrick2011}}
 | label9 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(K ([[Astronomy:Mauna Kea Observatory|MKO]] filter system)</small>
 |  data9 = {{val|18.80|0.04}}<ref name=Liu2012/>
 | header10 = Component A
 | label11 = Spectral type
 |  data11 = T8.5<ref name=Liu2013/>
 | label12 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(Y ([[Astronomy:Mauna Kea Observatory|MKO]] filter system)</small>
 |  data12 = {{val|18.59|0.04}}<ref name=Liu2012/>
 | label13 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(J ([[Astronomy:Mauna Kea Observatory|MKO]] filter system)</small>
 |  data13 = {{val|17.98|0.02}}<ref name=Liu2012/>
 | label14 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(H ([[Astronomy:Mauna Kea Observatory|MKO]] filter system)</small>
 |  data14 = {{val|18.31|0.05}}<ref name=Liu2012/>
 | label15 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(K ([[Astronomy:Mauna Kea Observatory|MKO]] filter system)</small>
 |  data15 = {{val|18.94|0.04}}<ref name=Liu2012/>
 | header16 = Component B
 | label17 = Spectral type
 |  data17 = Y0-0.5<ref name=Liu2013/>
 | label18 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(Y ([[Astronomy:Mauna Kea Observatory|MKO]] filter system)</small>
 |  data18 = {{val|20.26|0.04}}<ref name=Liu2012/>
 | label19 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(J ([[Astronomy:Mauna Kea Observatory|MKO]] filter system)</small>
 |  data19 = {{val|20.08|0.03}}<ref name=Liu2012/>
 | label20 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(H ([[Astronomy:Mauna Kea Observatory|MKO]] filter system)</small>
 |  data20 = {{val|20.51|0.06}}<ref name=Liu2012/>
 | label21 = [[Astronomy:Apparent magnitude|Apparent magnitude]] <small>(K ([[Astronomy:Mauna Kea Observatory|MKO]] filter system)</small>
 |  data21 = {{val|21.10|0.12}}<ref name=Liu2012/>
}}
{{Starbox astrometry
|prop_mo_ra={{val|754.9|1.2}}
|prop_mo_dec={{val|-1249.8|1.8}}
|pm_footnote=<ref name="Kirkpatrick2021"/>
|parallax=107.4
|p_error=3.5
|parallax_footnote=<ref name="Kirkpatrick2021"/>
}}
{{Starbox orbit
|reference=<ref name=Liu2012/>
|primary=A
|name=B
|period=130{{±|230|30}}
}}
{{Starbox detail
|component1=Component A
|mass_mj=30<ref name=Liu2013/>
|luminosity_bolometric=10<sup>−5.95 ± 0.18</sup><ref name=Liu2012/>
|gravity={{val|5.07|0.05}}<ref name=Liu2012/>
|temperature=575{{±|25}}<ref name=Liu2013/>
|age_gyr=6{{±|2}}<ref name=Liu2013/>
|component2=Component B
|mass_mj2=22<ref name=Liu2013/>
|luminosity_bolometric2=10<sup>−6.79 ± 0.18</sup><ref name=Liu2012/>
|gravity2={{val|4.77|0.05}}<ref name=Liu2012/>
|temperature2=450{{±|50}}<ref name=Liu2013/>
}}
{{Starbox relpos
| epoch = [[Astronomy:Universal Time|UT]] 2012 January 29
| primary = A
| component = B
| angdistmas = {{val|758.2|1.4}}
| angdistref = <ref name=Liu2012/>
| posang = {{val|14.50|0.13}}
| posangref = <ref name=Liu2012/>
| projsep = ~ 8
| projsepref = <ref name=Liu2012/>
}}
{{Starbox catalog
|names=[[Astronomy:Wide-field Infrared Survey Explorer|WISEPC]] J121756.91+162640.2{{r|Kirkpatrick2011}}<br />[[Astronomy:Wide-field Infrared Survey Explorer|WISE]] J1217+1626{{r|Kirkpatrick2011|Liu2012}}<br />[[Astronomy:Wide-field Infrared Survey Explorer|WISE]] 1217+1626{{r|Kirkpatrick2011}}<br />[[Astronomy:Wide-field Infrared Survey Explorer|WISE]] J1217+1626AB,<ref name=Liu2012/> WISE J121756.90+162640.8
}}
{{Starbox reference
| Simbad = WISE+J121756.90%2B162640.8
}}
{{Starbox end}}

'''WISEPC J121756.91+162640.2''' (designation abbreviated to '''WISE 1217+1626''', or '''WISE J1217+1626''') is a binary [[Astronomy:Brown dwarf|brown dwarf]] system of spectral classes T9 + Y0,<ref name=Liu2012/> located in constellation [[Astronomy:Coma Berenices|Coma Berenices]] at approximately 30.4 [[Astronomy:Light-year|light-year]]s from [[Astronomy:Earth|Earth]].<ref name="Kirkpatrick2021"/>

==History of observations==

===Discovery===
'''WISE 1217+1626 A''' was discovered in 2011 by J. Davy Kirkpatrick ''et al.'' from data, collected by [[Astronomy:Wide-field Infrared Survey Explorer|Wide-field Infrared Survey Explorer (WISE)]] Earth-orbiting [[Astronomy:Satellite|satellite]] — [[Organization:National Aeronautics and Space Administration|NASA]] [[Physics:Infrared|infrared-wavelength]] 40 cm (16 [[Inch|in]]) space telescope, which mission lasted from December 2009 to February 2011. In 2011 Kirkpatrick ''et al.'' published a paper in ''The Astrophysical Journal Supplement'', where they presented discovery of 98 new found by WISE [[Astronomy:Brown dwarf|brown dwarf]] systems with components of spectral types M, L, T and Y, among which also was WISE 1217+1626.{{r|Kirkpatrick2011}}<ref name="note 1" group="~">These 98 brown dwarf systems are only among first, not all brown dwarf systems, discovered from data, collected by WISE: six discoveries were published earlier (however, also listed in Kirkpatrick ''et al.'' (2011)) in Mainzer ''et al.'' (2011) and Burgasser ''et al.'' (2011), and the other discoveries were published later.</ref>

===Initial estimate of spectral type===
Initial estimate of WISE 1217+1626' spectral type (before discovery of its binarity) was T9{{r|Kirkpatrick2011|Kirkpatrick2012}} (the same as the component's A type estimate made after this discovery).<ref name=Liu2012/>

===Discovery of component B===
'''WISE 1217+1626 B''' was discovered in 2012 by Liu ''et al.'' with [[Physics:Laser guide star|laser guide star (LGS)]] [[Astronomy:Adaptive optics|adaptive optics (AO)]] system of the 10-m Keck II Telescope on [[Astronomy:Mauna Kea Observatory|Mauna Kea]], Hawaii, using [[Physics:Infrared|infrared]] camera NIRC2 (the observations were made on 2012 January 29 ([[Astronomy:Universal Time|UT]])). On 2012 April 1 ([[Astronomy:Universal Time|UT]]) Liu ''et al.'' observed WISE J1217+1626AB using the near-IR camera NIRI on the Gemini-North 8.1-m telescope on [[Astronomy:Mauna Kea Observatory|Mauna Kea]], Hawaii and the binary was marginally resolved. On 12 April 2012 ([[Astronomy:Universal Time|UT]]) they obtained resolved [[Physics:Spectroscopy|spectroscopy]] of WISE J1217+1626AB with the near-IR [[Astronomy:Spectrograph|spectrograph]] NIRSPEC again on the Keck II Telescope. In 2012 Liu ''et al.'' published a paper in ''[[Astronomy:The Astrophysical Journal|The Astrophysical Journal]]'' where they presented results of observations with Keck II [[Physics:Laser guide star|LGS]]-[[Astronomy:Adaptive optics|AO]] of three brown dwarf binary systems, binarity of one of which was known before, and binarity of the other two, including WISE 1217+1626, was first presented in this paper.<ref name=Liu2012/>

==Physical properties==
Using three models, Liu ''et al.'' calculated physical properties of WISE 1217+1626 components for ages of 1 and 5 billion years.<ref name=Liu2012/> Later, models corresponding to age of the system equal to 1 billion years, were found to be poorly fitting and were discarded.<ref name=Liu2013/>

'''From Burrows ''et al.'' (2003) models and M(J)''':
{| class="wikitable"
|-
! Component and<br />assumed age !! [[Physics:Mass|Mass]],<br />{{Jupiter mass|Jup=y|link=y}} !! [[Astronomy:Effective temperature|T<sub>eff</sub>]],<br />[[Kelvin|K]] !! log [[Physics:Surface gravity|g]],<br />cm/[[Second|s]]<sup>2</sup> !! [[Astronomy:Orbital period|P]],<br />[[Year|yr]]
|-
| '''A''' (for 5 Gyr) || {{val|29|3}}      || {{val|530|30}} || {{val|4.95|0.05}} ||
|-
| '''B''' (for 5 Gyr) || {{val|18.4|1.0}}  || {{val|402|11}} || {{val|4.68|0.03}} || {{val|130|+230|-30}}
|}

'''From Lyon/COND models and M(J)''':
{| class="wikitable"
|-
! Component and<br />assumed age !! [[Physics:Mass|Mass]],<br />{{Jupiter mass|Jup=y|link=y}} !! [[Astronomy:Effective temperature|T<sub>eff</sub>]],<br />[[Kelvin|K]] !! log [[Physics:Surface gravity|g]],<br />cm/[[Second|s]]<sup>2</sup> !! [[Astronomy:Orbital period|P]],<br />[[Year|yr]]
|-
| '''A''' (for 5 Gyr) || {{val|8.3|0.9}}  || {{val|660|40}} || {{val|5.07|0.05}} ||
|-
| '''B''' (for 5 Gyr) || {{val|20|2}}     || {{val|470|30}} || {{val|4.77|0.05}} || {{val|120|+220|-30}}
|}

'''From Lyon/COND models and L<sub>bol</sub>''':
{| class="wikitable"
|-
! Component and<br />assumed age !! [[Physics:Mass|Mass]],<br />{{Jupiter mass|Jup=y|link=y}} !! [[Astronomy:Effective temperature|T<sub>eff</sub>]],<br />[[Kelvin|K]] !! log [[Physics:Surface gravity|g]],<br />cm/[[Second|s]]<sup>2</sup> !! [[Astronomy:Orbital period|P]],<br />[[Year|yr]]
|-
| '''A''' (for 5 Gyr) || {{val|33|5}}    || {{val|630|70}} || {{val|5.04|0.09}} ||
|-
| '''B''' (for 5 Gyr) || {{val|13|3}}    || {{val|370|50}} || {{val|4.54|0.11}} || {{val|130|+240|-30}}
|}
Both components have a thin cloud layers in atmosphere. Despite being cold enough to have a chloride and sulfide clouds in atmosphere, component B atmosphere is not as cloudy as expected, possibly because of the system been metal-poor.<ref name=Liu2013/>

==See also==
*[[Astronomy:WISE J0336−0143|WISE J0336−0143]] – first Y + Y binary brown dwarf system discovered
The other two brown dwarf binary systems, observed by Liu ''et al.'' with Keck II [[Physics:Laser guide star|LGS]]-[[Astronomy:Adaptive optics|AO]] in 2012:<ref name=Liu2012/>
* WISE 1711+3500 (T8 + T9.5, binarity was newly discovered)
* [[Astronomy:CFBDSIR 1458+10|CFBDSIR 1458+10]] (T9 + Y0, binarity was known before)

==Notes==
{{reflist|colwidth=30em|group=~}}

==References==
{{reflist|colwidth=30em|refs=

<ref name="Kirkpatrick2011">{{cite journal |doi=10.1088/0067-0049/197/2/19 |last1=Kirkpatrick |first1=J. Davy |last2=Cushing |first2=Michael C. |last3=Gelino |first3=Christopher R. |last4=Griffith |first4=Roger L. |last5=Skrutskie |first5=Michael F. |last6=Marsh |first6=Kenneth A. |last7=Wright |first7=Edward L. |last8=Mainzer |first8=Amy K. |last9=Eisenhardt |first9=Peter R. |last10=McLean |first10=Ian S. |last11=Thompson |first11=Maggie A. |last12=Bauer |first12=James M. |last13=Benford |first13=Dominic J. |last14=Bridge |first14=Carrie R. |last15=Lake |first15=Sean E. |last16=Petty |first16=Sara M. |last17=Stanford |first17=Spencer Adam |last18=Tsai |first18=Chao-Wei |last19=Bailey |first19=Vanessa |last20=Beichman |first20=Charles A. |last21=Bloom |first21=Joshua S. |last22=Bochanski |first22=John J. |last23=Burgasser |first23=Adam J. |last24=Capak |first24=Peter L. |last25=Cruz |first25=Kelle L. |last26=Hinz |first26=Philip M. |last27=Kartaltepe |first27=Jeyhan S. |last28=Knox |first28=Russell P. |last29=Manohar |first29=Swarnima |last30=Masters |first30=Daniel |last31=Morales-Calderon |first31=Maria |last32=Prato |first32=Lisa A. |last33=Rodigas |first33=Timothy J. |last34=Salvato |first34=Mara |last35=Schurr |first35=Steven D. |last36=Scoville |first36=Nicholas Z. |last37=Simcoe |first37=Robert A. |last38=Stapelfeldt |first38=Karl R. |last39=Stern |first39=Daniel |last40=Stock |first40=Nathan D. |last41=Vacca |first41=William D. |title=The First Hundred Brown Dwarfs Discovered by the Wide-field Infrared Survey Explorer (WISE) |date=2011 |journal=The Astrophysical Journal Supplement |volume=197 |issue=2 |pages=19 |arxiv=1108.4677v1 |bibcode=2011ApJS..197...19K |s2cid=16850733 }}</ref>

<ref name="Kirkpatrick2012">{{cite journal |last1=Kirkpatrick |first1=J. Davy |last2=Gelino |first2=Christopher R. |last3=Cushing |first3=Michael C. |last4=Mace | first4=Gregory N. |last5=Griffith |first5=Roger L. |last6=Skrutskie |first6=Michael F. |last7=Marsh |first7=Kenneth A. |last8=Wright |first8=Edward L. |last9=Eisenhardt |first9=Peter R. |last10=McLean |first10=Ian S. |last11=Mainzer | first11=Amy K. |last12=Burgasser |first12=Adam J. |last13=Tinney |first13=Chris G. |last14=Parker |first14=Stephen |last15=Salter |first15=Graeme |title=Further Defining Spectral Type "Y" and Exploring the Low-mass End of the Field Brown Dwarf Mass Function |year=2012 |journal=[[Astronomy:The Astrophysical Journal|The Astrophysical Journal]] |volume=753 |issue=2 |pages=156 |arxiv=1205.2122 |doi=10.1088/0004-637X/753/2/156 |bibcode=2012ApJ...753..156K |s2cid=119279752 }}</ref>

<ref name=Liu2012>{{cite journal | last=Liu |first=Michael C. |author2=Dupuy, Trent J. |author3=Bowler, Brendan P. |author4=Leggett, S. K. |author5=Best, William M. J. | title=Two Extraordinary Substellar Binaries at the T/Y Transition and the Y-band Fluxes of the Coolest Brown Dwarfs | year=2012 | journal=[[Astronomy:The Astrophysical Journal|The Astrophysical Journal]] | volume=758 | issue=1 | pages=57 | arxiv=1206.4044 | doi=10.1088/0004-637X/758/1/57 | bibcode=2012ApJ...758...57L|s2cid=118402490 }}</ref>

<!--<ref name="Dupuy2013">{{Cite journal
 | doi = 10.1126/science.1241917
| title = Distances, Luminosities, and Temperatures of the Coldest Known Substellar Objects
| journal = Science
| volume = 341
| issue = 6153
| pages = 1492–5
| year = 2013
| last1 = Dupuy | first1 = T. J.
| last2 = Kraus | first2 = A. L.
|arxiv = 1309.1422 |bibcode = 2013Sci...341.1492D | pmid=24009359| s2cid = 30379513
}}</ref>-->

<ref name=Liu2013>{{citation|arxiv=1311.2108|title=Resolved Spectroscopy of the T8.5 and Y0-0.5 Binary Wisepc J121756.91+162640.2Ab|year=2013|doi=10.1088/0004-637X/780/1/62 |last1=Leggett |first1=S. K. |last2=Liu |first2=Michael C. |last3=Dupuy |first3=Trent J. |last4=Morley |first4=Caroline V. |last5=Marley |first5=M. S. |last6=Saumon |first6=D. |journal=The Astrophysical Journal |volume=780 |page=62 |s2cid=118412221 }}</ref>

<ref name="Kirkpatrick2021">{{cite journal |last1=Kirkpatrick |first1=J. Davy |last2=Gelino |first2=Christopher R. |display-authors=0 |date=March 2021 |title=The Field Substellar Mass Function Based on the Full-sky 20 pc Census of 525 L, T, and Y Dwarfs |journal=The Astrophysical Journal Supplement Series |volume=253 |issue=1 |pages=7 |doi=10.3847/1538-4365/abd107 |arxiv=2011.11616 |bibcode=2021ApJS..253....7K|s2cid=227126954 |doi-access=free }}</ref>

}}

{{Stars of Coma Berenices}}

{{DEFAULTSORT:WISE 1217+1626}}
[[Category:Binary stars]]
[[Category:Brown dwarfs]]
[[Category:Coma Berenices]]
[[Category:WISE objects]]

{{Sourceattribution|WISE 1217+1626}}