MAIA Maid stars

Observation

Small amplitudes Short periods <2> CCD or PEP

- In 1955, the Maia10 variable stars were predicted to exist within the spectral range B7-A2, possess periods between I and 4 hours and reside within the HR diagram between fi Cephei and 5 Scuti stars. Maia, the prototype for this group of stars, has a long history of suspected variability. Together with a second star, y Ursa Minoris (A3 II-II1 or A3 V), these two stars have been suggested to form the ends of the hypothetical Maia sequence. Both stars are listed within the Yale Catalog of Bright Stars as variable.

Over the years, several searches have been conducted in an attempt to unambiguously locate the Maia variables. As recently as 1987 it was concluded that their existence was doubtful because no variability had been detected within the small group of suspects. Recently, a search using the Hipparcos epoch photometry database was conducted in an effort to search for the elusive Maia pulsating variable stars. Several hundred stars were considered, and several dozen stars studied in detail; however, only a handful are possible variables: three are possible shallow eclipsing variables; three have possible periods in the range 0^25-0^5 but their amplitudes are so small that they are probably non-variable, y UMi shows an irregular variation ranging from 0^0143009 to Oi114335 and a Am < 0™05. It has also been suggested that y UMi may be surrounded by a short-lived tenuous shell.

Maia and y UMi are now regarded as photometrically constant. Perhaps like the abominable snowman, these stars may exist but are extremely difficult to find.

'"Named for Maia (20 Tau = HR 1149 = HD 23408), one of the brighter stars found within the Pleiades star cluster.

0 0

Post a comment