Speckle Interferometry at the US Naval Observatory. IX.

Abstract

The results of 3056 speckle interferometric observations of double stars, made with the 26 inch (66 cm) refractor of the US Naval Observatory, are presented. Each speckle interferometric observation of a system represents a combination of over a thousand short-exposure images. These observations are averaged into 1675 mean relative positions and range in separation from 0B19 to 45B21, with a median separation of 2B99. This is the ninth in a series of papers presenting measures obtained with this system and covers the period 2002 January 1 through 2002 December 29. Included in these data are 28 older measures whose positions were previously deemed possibly aberrant but are no longer classified this way following a confirming observation. Nine of these systems have new orbital elements, which are presented here as well.

Speckle Interferometry at the US Naval Observatory. X.

“…Also included in these data are nine observations with the same USNO speckle camera system from 2002. These measures were not published in Mason et al (2004), as they were significantly different from previous observations or orbital predictions; however, they have now been confirmed with new measures obtained in 2003. Some of these discrepancies reflect the prematurity of earlier orbit calculations; for four of these systems we were able to obtain new elements that, although still preliminary, allow for better ephemerides to be published.…”

“…Two hundred fifty-six have not been observed in the last 50 years or more, and 21 have not been observed in 100 years or more, with the maximum being 111 years for BRT 2491 ( Barton 1939). Of those confirmed, 48 are relatively recent: four from Hipparcos ( ESA 1997), 40 from Tycho ( Høg et al 2000a( Høg et al , 2000bMason et al 2000;Fabricius et al 2002), and four discovered with the USNO speckle system ( Mason et al 1999b on either the USNO 26 inch or the McDonald 2.1 m. Of the 1406 measures in Table 2 (i.e., systems without orbits), the median separation is 9B0.…”

“…The observing list was constructed using the same methodology discussed in Mason et al (2004). The majority of the systems were those that are considered neglected (the last date of observation was 10 or more years ago) or doubles needing confirmation.…”

“…Not all nights were scheduled, as a consequence of either instrumental difficulties or the camera's being removed for other observing projects or runs. Further details describing the techniques and methodology of speckle interferometry are contained in the earlier papers in this series and references therein (most recently, Mason et al 2004).…”

Spectroscopic analysis of the B/Be visual binary HR 1847

“…• 8 (Mason et al 2004, from speckle interferometry). The angular separation, as reported by Lindroos (1983) and Abt & Cardona (1984) is 9.…”