{"id":510,"date":"2009-12-05T01:30:33","date_gmt":"2009-12-05T01:30:33","guid":{"rendered":"http:\/\/perezmedia.net\/beltofvenus\/2009\/12\/05\/xi_scorpius_str\/"},"modified":"2009-12-05T01:30:33","modified_gmt":"2009-12-05T01:30:33","slug":"xi_scorpius_str","status":"publish","type":"post","link":"https:\/\/perezmedia.net\/beltofvenus\/2009\/12\/05\/xi_scorpius_str\/","title":{"rendered":"Xi Scorpii (Struve 1998) and Struve 1999"},"content":{"rendered":"
\"Sketch<\/a><\/p>\n

Sketch of Xi Scorpii (Struve 1998) and Struve 1999<\/p>\n

Click image to view larger version.<\/i><\/p>\n<\/div>\n

Observation Notes:<\/b><\/p>\n

There are a number of double-doubles scattered across the sky. Although Epsilon Lyrae may be the best known, there’s really some great competition out there. Xi Scorpii\/Struve 1998 and its southern counterpart, Struve 1999, are a brilliant and beautiful sight in the northern reaches of the scorpion. These two yellow\/orange pairs are separated from each other by under 5 arc minutes.<\/p>\n

Struve 1998 appeared as a bright yellow primary with an orange secondary 8 arc seconds to the northeast. The primary of Struve 1998 is itself another close double, separated by 0.9 arc seconds. I just made out its pill-shaped elongation and roughly measured a PA of 1 degree. It’s actual position is 10 degrees further clockwise at PA 351 degrees. Struve 1999 was a fainter pair and the color more subtle, but still a yellow primary with an orange secondary 11 arc seconds to the east.<\/p>\n

This is definitely another sight not to be missed by the double star enthusiast. Be sure to catch it next summer!<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Subject<\/b><\/td>\nXi Scorpii\/STF 1998 and STF 1999 (ADS 9909 and ADS 9910)<\/td>\n<\/tr>\n
Classification<\/b><\/td>\nMultiple Star<\/td>\n<\/tr>\n
Position (J2000)*<\/b><\/td>\nSTF 1998: Scorpius [RA: 16 04 22.3 \/ Dec: -11 22 20]
STF 1999: Scorpius [RA: 16 04 25.9 \/ Dec: -11 26 57.8]*<\/td>\n<\/tr>\n
Position Angle<\/b><\/td>\nSTF 1998<\/b>
\nAB: 1° [My Measurement 2009.3]
\n351° [WDS 2008]*
\nAC: 47° [My Measurement 2009.3]
\nAC: 41° [WDS 2005]<\/p>\n

STF 1999<\/b>
\nAB: 102° [My Measurement 2009.3]
\nAB: 99° [WDS 2007]*
\nAC: 84° [WDS 1999]*
\nAD: 351° [WDS 2006]<\/td>\n<\/tr>\n

Separation<\/b><\/td>\nSTF 1998<\/b>
\nAB: 0.7″ [My Measurement 2009.3]
\n0.9″ [WDS 2008]*
\nAC: 8″ [My Measurement 2009.3]
\nAC: 7.9″ [WDS 2005]<\/p>\n

STF 1999<\/b>
\nAB: 11″ [My Measurement 2009.3]
\nAB: 11.8″ [WDS 2007]*
\nAC: 83.1″ [WDS 1999]*
\nAD: 278.5″ [WDS 2006]<\/td>\n<\/tr>\n

Magnitudes*<\/b><\/td>\nSTF 1998 – <\/b>A: 4.9; B: 5.2; C: 7.3
STF 1999 – <\/b>A: 7.5; B: 8.1; C: 11.0; D: 4.4<\/td>\n<\/tr>\n
Spectral Types*<\/b><\/td>\nSTF 1998 – <\/b>A: F5IV; B: G1V; C: F7IV
STF 1999 – <\/b>A: G8V+; B: K1V(k)<\/td>\n<\/tr>\n
Date\/Time<\/b><\/td>\nAPR 5, 2009 – 2:15 AM (APR 5, 2008 – 09:15 UT)<\/td>\n<\/tr>\n
Observing Loc.<\/b><\/td>\nFlagstaff, AZ – Home<\/td>\n<\/tr>\n
Instrument<\/b><\/td>\nOrion SkyQuest XT8 Dobsonian (203 mm dia.\/1200 mm F\/L)<\/td>\n<\/tr>\n
Eyepieces\/Mag.<\/b><\/td>\nPentax XW10 + 2X Barlow (240X)
Meade Astrometric EP + 2X Barlow (200X)<\/td>\n<\/tr>\n
Conditions<\/b><\/td>\nClear, light breeze<\/td>\n<\/tr>\n
Seeing<\/b><\/td>\n5\/10 Pickering<\/td>\n<\/tr>\n
Transparency<\/b><\/td>\nMag 5.2 NELM<\/td>\n<\/tr>\n
*References<\/b><\/td>\nThe Washington Visual Double Star Catalog (Mason+ 2001-2009); Catalogue of Stellar Spectral Classifications (Skiff, 2009); SIMBAD<\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

Xi Scorpii<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[16,56,57,26,15],"tags":[],"class_list":["post-510","post","type-post","status-publish","format-standard","hentry","category-deep-sky","category-double-star","category-sg-double-star","category-sgc-scorpius","category-sketch-gallery"],"jetpack_featured_media_url":"","jetpack-related-posts":[{"id":14,"url":"https:\/\/perezmedia.net\/beltofvenus\/2004\/08\/01\/double_star_ske\/","url_meta":{"origin":510,"position":0},"title":"Double Star Sketches","author":"jperez1690","date":"August 1, 2004","format":false,"excerpt":"Double Star Sketches","rel":"","context":"In "General"","block_context":{"text":"General","link":"https:\/\/perezmedia.net\/beltofvenus\/category\/general\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":508,"url":"https:\/\/perezmedia.net\/beltofvenus\/2009\/12\/02\/struve_2194\/","url_meta":{"origin":510,"position":1},"title":"Struve 2194","author":"jperez1690","date":"December 2, 2009","format":false,"excerpt":"Struve 2194","rel":"","context":"In "Deep Sky"","block_context":{"text":"Deep Sky","link":"https:\/\/perezmedia.net\/beltofvenus\/category\/deep-sky\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":506,"url":"https:\/\/perezmedia.net\/beltofvenus\/2009\/11\/30\/struve_1374\/","url_meta":{"origin":510,"position":2},"title":"Struve 1374","author":"jperez1690","date":"November 30, 2009","format":false,"excerpt":"Struve 1374","rel":"","context":"In "Deep Sky"","block_context":{"text":"Deep Sky","link":"https:\/\/perezmedia.net\/beltofvenus\/category\/deep-sky\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":255,"url":"https:\/\/perezmedia.net\/beltofvenus\/2006\/06\/13\/struve_3053\/","url_meta":{"origin":510,"position":3},"title":"Struve 3053","author":"jperez1690","date":"June 13, 2006","format":false,"excerpt":"Struve 3053","rel":"","context":"In "Double Star"","block_context":{"text":"Double Star","link":"https:\/\/perezmedia.net\/beltofvenus\/category\/double-star\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":497,"url":"https:\/\/perezmedia.net\/beltofvenus\/2009\/10\/09\/epsilon_monocer\/","url_meta":{"origin":510,"position":4},"title":"Epsilon Monocerotis (Struve 900)","author":"jperez1690","date":"October 9, 2009","format":false,"excerpt":"Epsilon Monocerotis","rel":"","context":"In "Deep Sky"","block_context":{"text":"Deep Sky","link":"https:\/\/perezmedia.net\/beltofvenus\/category\/deep-sky\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":451,"url":"https:\/\/perezmedia.net\/beltofvenus\/2008\/12\/26\/12_lyncis_struv\/","url_meta":{"origin":510,"position":5},"title":"12 Lyncis (Struve 948)","author":"jperez1690","date":"December 26, 2008","format":false,"excerpt":"12 Lyncis","rel":"","context":"In "Double Star"","block_context":{"text":"Double Star","link":"https:\/\/perezmedia.net\/beltofvenus\/category\/double-star\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/posts\/510","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/comments?post=510"}],"version-history":[{"count":0,"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/posts\/510\/revisions"}],"wp:attachment":[{"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/media?parent=510"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/categories?post=510"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/tags?post=510"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}