Editing 61 Cygni (section)

=== Refining planetary boundaries ===
Since no certain planetary object has been detected around either star so far, [[McDonald Observatory]] team has set limits to the presence of one or more planets around 61 Cygni A and 61 Cygni B with masses between 0.07 and 2.1&nbsp;Jupiter masses and average separations spanning between 0.05 and 5.2&nbsp;AU.<ref>{{cite journal
  | author=Wittenmyer, R. A.
 | author2=Endl, M.
 | author3=Cochran, W.D.
 | author4=Hatzes, A.
 | author5=Walker, G. A. H.
 | author6=Yang, S. L. S.
 | author7=Paulson, D. B.
 | title=Detection Limits from the McDonald Observatory Planet Search Program | journal=[[The Astronomical Journal]]
 |date=May 2006 | volume=132 | issue=1
 | pages=177–188 | doi=10.1086/504942 | bibcode=2006AJ....132..177W
 | arxiv=astro-ph/0604171| s2cid=16755455
 }}</ref>

Because of the proximity of this system to the Sun, it is a frequent target of interest for astronomers. Both stars were selected by [[NASA]] as "Tier 1" targets for the proposed optical [[Space Interferometry Mission]].<ref>{{cite web
 |url         = http://tauceti.sfsu.edu/~chris/SIM/t1.html
 |title       = SIM Planet Search Tier 1 Target Stars
 |first       = Christopher
 |last        = McCarthy
 |year        = 2005
 |publisher   = [[San Francisco State University]]
 |access-date  = 23 July 2007
 |archive-url  = https://web.archive.org/web/20070804210039/http://tauceti.sfsu.edu/~chris/SIM/t1.html
 |archive-date = 4 August 2007
 }}</ref> This mission is potentially capable of detecting planets with as little as 3&nbsp;times the mass of the Earth at an orbital distance of 2&nbsp;AU from the star.

Measurements of this system appeared to have detected an [[infrared excess|excess of far infrared radiation]], beyond what is emitted by the stars. Such an excess is sometimes associated with a [[debris disk|disk of dust]], but in this case it lies sufficiently close to one or both of the stars that it has not been resolved with a telescope.<ref>{{cite journal
 | author=Kuchner, Marc J.
 | author2=Brown, Michael E.
 | author3=Koresko, Chris D.
 | title=An 11.6 Micron Keck Search for Exo-Zodiacal Dust
 | journal=The Publications of the Astronomical Society of the Pacific
 | date=1998 | volume=110 | issue=753 | pages=1336–1341
 | bibcode=1998PASP..110.1336K
 | doi=10.1086/316267 |arxiv = astro-ph/0002040 | s2cid=119479494
 }}</ref> A 2011 study using the [[W. M. Keck Observatory|Keck Interferometer Nuller]] failed to detect any [[exozodiacal dust]] around 61 Cygni A.<ref>{{Citation |last1=Millan-Gabet, R. |title=Exozodiacal Dust Levels for Nearby Main-sequence Stars: A Survey with the Keck Interferometer |date=June 2011 |journal=The Astrophysical Journal |volume=734 |issue=1 |page=67 |postscript=. |arxiv=1104.1382 |bibcode=2011ApJ...734...67M |doi=10.1088/0004-637X/734/1/67 |last2=Serabyn, E. |last3=Mennesson, B. |last4=Traub, W. A. |last5=Barry, R. K. |last6=Danchi, W. C. |last7=Kuchner, M. |last8=Stark, C. C. |last9=Ragland, S. |last10=Hrynevych, M. |last11=Woillez, J. |last12=Stapelfeldt, K. |last13=Bryden, G. |last14=Colavita, M. M. |last15=Booth, A. J.|s2cid=118614703 }} See Table 5, p. 58.</ref>