{"id":283,"date":"2012-07-08T21:00:00","date_gmt":"2012-07-08T21:00:00","guid":{"rendered":"http:\/\/perezmedia.net\/beltofvenus\/2012\/07\/08\/epsilon_lyrae_s\/"},"modified":"2023-12-25T04:29:03","modified_gmt":"2023-12-25T04:29:03","slug":"epsilon_lyrae_s","status":"publish","type":"post","link":"https:\/\/perezmedia.net\/beltofvenus\/2012\/07\/08\/epsilon_lyrae_s\/","title":{"rendered":"Epsilon Lyrae (Struve-A 37, Struve 2382, 2383)"},"content":{"rendered":"
<\/a><\/div>\n

The 2006 sketch has gotten a lot of mileage and I really needed to re-observe, redraw and measure the double double. I had some confusion when comparing my measurements with the WDS later. I measured 172 degrees PA for AB-CD. However, the WDS listed 182 degrees for 2010 and besides my notes, I clearly remembered the PA being clockwise from south.<\/p>\n

I checked in with Brian Skiff to see if he thought I was completely missing something, and since he keeps good contact with Brian Mason and others at the USNO. He contacted them and they provided a full table of WDS measurements for all components in the system going back to 1777.<\/p>\n

The two most recent PA entries in 2010 have a notation next to them showing that something odd was flagged. Prior to that, for the past century, the measurements were mostly consistent to 172 degrees. I used the WDS data to plot a basic line chart showing PA and separating measurements for AB-CD from 1830 to present. It’s interesting to see both measurements start to show increasing variation starting in the 1940s, with PA showing the most noticeable deviation.<\/p>\n

<\/a>
\nChart showing Separation and PA measurements of epsilon Lyrae AB-CD from 1830 to 2011.<\/div>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Subject<\/b><\/td>\nEpsilon Lyrae (STFA 37, STF 2382, STF 2383)<\/td>\n<\/tr>\n
Classification<\/b><\/td>\nMultiple Star<\/td>\n<\/tr>\n
Position (J2000)<\/b><\/td>\nLyra:
\ne1a-Lyr\/STF 2382 [RA: 18 44 20.34 \/ Dec: +39 40 12.4]
\ne2a-Lyr\/STF 2383 [RA: 18 44 22.7 \/ Dec: +39 36 46]*<\/td>\n<\/tr>\n
Position Angle*<\/b><\/td>\nAB: 347\u00b0 [My measurement 2012.5] \/ 346\u00b0 [WDS 2010]
\nCD: 75\u00b0 [My measurement 2012.5] \/ 79\u00b0 [WDS 2010]
\nAB-CD: 172\u00b0 [My measurement 2012.5] \/ 172.8\u00b0 [WDS 2010.6]<\/td>\n<\/tr>\n
Separation*<\/b><\/td>\nAB: 2.2″ [My measurement 2012.5] \/ 2.2″ [WDS 2010]
\nCD: 2.9″ [My measurement 2012.5] \/ 2.3″ [WDS 2010]
\nAB-CD: 205″ [My measurement 2012.5] \/ 208.1″ [WDS 2010.6]<\/td>\n<\/tr>\n
Magnitudes*<\/b><\/td>\nA: 5.15; B: 6.10; C: 5.25; D: 5.38; AB: 4.67; CD: 4.56<\/td>\n<\/tr>\n
Spectral Types*<\/b><\/td>\nA: A4V; B: F1V; C: A8Vn; D: F0Vn<\/td>\n<\/tr>\n
Date\/Time<\/b><\/td>\nJUNE 28, 2012 – 10:15 PM MST (JUNE 29, 2012 – 0515 UT)<\/td>\n<\/tr>\n
Observing Loc.<\/b><\/td>\nFlagstaff, AZ – Home<\/td>\n<\/tr>\n
Instrument<\/b><\/td>\nOrion SVP 6LT Reflector (150 mm dia.\/1200 mm F\/L)<\/td>\n<\/tr>\n
Eyepieces\/Mag.<\/b><\/td>\nPentax XW10 + 2X Barlow (240X)
\n12 mm Meade Astrometric + 2X Barlow (200X)
\n4 mm UO Orthoscopic + 2X Barlow (600X)<\/td>\n<\/tr>\n
Conditions<\/b><\/td>\nClear, 1st quarter moon, breezy<\/td>\n<\/tr>\n
Seeing<\/b><\/td>\n4\/10 Pickering<\/td>\n<\/tr>\n
Transparency<\/b><\/td>\n19.7 Mag.\/arcsec^2<\/td>\n<\/tr>\n
*References<\/b><\/td>\nThe Washington Visual Double Star Catalog (Mason+ 2001-2012)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
\n

Observation Notes and Sketch: September 4, 2006<\/b><\/p>\n

<\/p>\n

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

This pair of pairs is such a wild sight. I didn’t notice any color. Using just my stargazing glasses, I am able to split the main pair which have a separation of 209 arc seconds.<\/p>\n\n\n\n\n\n\n\n\n\n
Date\/Time<\/b><\/td>\nSEP 04, 2006 – 12:55 AM MST (SEP 04, 2006 – 07:55 UT)<\/td>\n<\/tr>\n
Observing Loc.<\/b><\/td>\nFlagstaff, AZ – Home<\/td>\n<\/tr>\n
Instrument<\/b><\/td>\nOrion SVP 6LT Reflector (150 mm dia.\/1200 mm F\/L)<\/td>\n<\/tr>\n
Eyepieces\/Mag.<\/b><\/td>\n10 mm Sirius Plossl + 2X Barlow (240X)<\/td>\n<\/tr>\n
Conditions<\/b><\/td>\nClear, calm<\/td>\n<\/tr>\n
Seeing<\/b><\/td>\n5\/10 Pickering<\/td>\n<\/tr>\n
Transparency<\/b><\/td>\nNELM Mag ~4.0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"

Epsilon Lyrae<\/p>\n","protected":false},"author":1,"featured_media":1081,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[56,57,71,15],"tags":[],"class_list":["post-283","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-double-star","category-sg-double-star","category-sgc-lyra","category-sketch-gallery"],"jetpack_featured_media_url":"https:\/\/perezmedia.net\/beltofvenus\/wp-content\/uploads\/2012\/07\/img2012062801_EpsilonLYR_lg_md-e1703478532727.jpg","jetpack-related-posts":[{"id":451,"url":"https:\/\/perezmedia.net\/beltofvenus\/2008\/12\/26\/12_lyncis_struv\/","url_meta":{"origin":283,"position":0},"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":[]},{"id":510,"url":"https:\/\/perezmedia.net\/beltofvenus\/2009\/12\/05\/xi_scorpius_str\/","url_meta":{"origin":283,"position":1},"title":"Xi Scorpii (Struve 1998) and Struve 1999","author":"jperez1690","date":"December 5, 2009","format":false,"excerpt":"Xi Scorpii","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":367,"url":"https:\/\/perezmedia.net\/beltofvenus\/2007\/10\/03\/alpha_ursae_maj\/","url_meta":{"origin":283,"position":2},"title":"Alpha Ursae Minoris (Polaris \/ Struve 93)","author":"jperez1690","date":"October 3, 2007","format":false,"excerpt":"Alpha Ursae Minoris","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":255,"url":"https:\/\/perezmedia.net\/beltofvenus\/2006\/06\/13\/struve_3053\/","url_meta":{"origin":283,"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":514,"url":"https:\/\/perezmedia.net\/beltofvenus\/2009\/12\/10\/struve_1604\/","url_meta":{"origin":283,"position":4},"title":"Struve 1604","author":"jperez1690","date":"December 10, 2009","format":false,"excerpt":"Struve 1604","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":363,"url":"https:\/\/perezmedia.net\/beltofvenus\/2007\/09\/24\/zeta_piscium_st\/","url_meta":{"origin":283,"position":5},"title":"Zeta Piscium (Struve 100)","author":"jperez1690","date":"September 24, 2007","format":false,"excerpt":"Zeta Piscium","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\/283","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=283"}],"version-history":[{"count":2,"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/posts\/283\/revisions"}],"predecessor-version":[{"id":1083,"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/posts\/283\/revisions\/1083"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/media\/1081"}],"wp:attachment":[{"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/media?parent=283"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/categories?post=283"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/perezmedia.net\/beltofvenus\/wp-json\/wp\/v2\/tags?post=283"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}