Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.naic.edu/vscience/schedule/tpfiles/LewistagA2328tp.pdf Дата изменения: Thu Jun 7 20:24:28 2007 Дата индексирования: Sun Apr 13 02:55:35 2008 Кодировка: Поисковые слова: stars

Proposal Identification No.:

A2328

Date Received:

2007-Jun-01 16:38:38

Technical Page
Proposal Type: General Category: Sub-Category: Observation Category: Total Time Requested: Minimum Useful Time: Prop osal Title: ABSTRACT: Long-term Astronomy Spectroscopy Galactic 24 Hours 45 mins

Are the 1612 MHz masers of IRAS 15060+0947 Modulated?

The 1612 MHz masers of the OH/IR star IRAS 15060+0947 exhibit unique behaviour. While its red peak has completely disappeared over 5 years, its blue peak has diminished to 25% of its discovery intensity, and oscillates in magnitude with a pulsation period of 315d. The mainline masers have constantly evolved, however, both in intensity and velocity. They were absent in November 2005, but are strong now, in a pattern suggesting that the star is evolving back through the phylogeny exhibited as the red peak disappeared. This behaviour challenges our ideas for explaining the appearance and disappearance of 1612 MHz masers from stars with an ongoing Mira pulsational period: we had expected the disappearance of the blue peak soon after that of the red. We therefore have lessons to learn, and so seek to continue monitoring this star monthly to follow the evolution in its complement of masers.

Name Brian M Lewis

Institution Arecibo Observatory

E-mail blewis@naic.edu

Phone 787 2612x285

878

Student no

Remote Observing Request

Observer will travel to AO Remote Observing X In Absentia (instructions to operator)

Instrument Setup
L-wide Atmospheric Observation Instruments:

Sp ecial Equipment or setup:

none 1


RFI Considerations Frequency Ranges Planned

2