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ICCD Speckle Observations of Binary Stars. XXIII. Measurements during 1982-1997 from Six Telescopes, with 14 New Orbits
We present 2017 observations of 1286 binary stars, observed by means ofspeckle interferometry using six telescopes over a 15 year period from1982 April to 1997 June. These measurements constitute the 23dinstallment in CHARA's speckle program at 2 to 4 m class telescopes andinclude the second major collection of measurements from the MountWilson 100 inch (2.5 m) Hooker Telescope. Orbital elements are alsopresented for 14 systems, seven of which have had no previouslypublished orbital analyses.
| The remarkable Herbig AE star V 351 Orionis=HD 38238.
The photometric behaviour of the irregular variable Herbig Ae star V 351Ori was investigated combining data from the literature with newphotometric data in the Stroemgren system. It is shown that thisenigmatic object changed its photometric behaviour from that of a HerbigAe star with strong photometric variations, due to extinction bycircumstellar dust clouds, to that of an almost non-variable star. Sucha behaviour is not unique; it has been found also in the star BN Ori(Shevchenko et al. 1996). This suggests that such transitions must occurquite often during the evolution of intermediate mass HAeBe starstowards the main-sequence (MS). However, it is equally probable thatbefore such a star arrives at the MS, it will become strongly variableagain after collecting enough dust from its environment. During theprocess of V 351 Ori's transition from a Herbig Ae star with strongphotometric variations to a non-variable one, the maximum brightness inthe Stroemgren v, b and y magnitudes decreased, whereas that in uincreased, causing a strong blueing effect in the colour-magnitudediagrams. It should be noted that this effect happened at a decrease invisual brightness by about 0.2mag magnitude only. It is therefore causedby a different mechanism than that in V 351 Ori before the transitionand in UX Ori type stars, where the blueing effect occurs at a decreasein V of about 2.5mag. The transition, from a strongly variable star tothe state in which V 351 Ori is nearly constant at a level equal to thatof its maximum brightness before the transition, happened very fast(within 50 days), and went along the interstellar reddening line in thecolour-magnitude diagrams. A provisional model to explain V 351 Ori'sbehaviour, in which it is assumed that a temporarily strong accretion ofmatter onto the star took place, is proposed.
| Longterm Photometry of Variables at ESO - Part Two - the Second Data Catalogue 1986-1990
Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1993A&AS..102...79S&db_key=AST
| Walraven photometry of nearby southern OB associations
Homogeneous Walraven (VBLUW) photometry is presented for 5260 stars inthe regions of five nearby southern OB associations: Scorpio Centaurus(Sco OB2), Orion OB1, Canis Major OB1, Monoceros OB1, and Scutum OB2.Derived V and (B - V) in the Johnson system are included.
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| Takýmyýldýz: | Avci |
| Sað Açýklýk: | 05h44m12.36s |
| Yükselim: | +00°57'29.9" |
| Görünürdeki Parlaklýk: | 8.649 |
| Uzaklýk: | 1234.568 parsek |
| özdevim Sað Açýklýk: | 0.7 |
| özdevim Yükselim: | -5.7 |
| B-T magnitude: | 8.93 |
| V-T magnitude: | 8.673 |
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