David's Astronomy Pages CCD Images - Session 32 (2002-11-24) Images (S28)   Images (Main)   Home Page   Images (S37)

Variable Stars 

25 variables in Pegasus, Andromeda, Lacerta and Triangulum were imaged using Automated Scripting (see Scripting).

6 of these variables were imaged  through the evening at approximately 25 minute intervals in an attempt to track variations in short-period variables. 

19 of these variables were imaged as part of an ongoing project to  track changes in longer period, mainly Mira type variables. (these variables were previously imaged on 2002-10-03 , 2002-10-23 and 2002-11-10 - see base line images).

Magnitudes were determined using CCDSoft , using offset Reference Stars (base line images).  Data was imported into Excel and compared with Magnitude estimates listed on VSNET [ http://vsnet.kusastro.kyoto-u.ac.jp/vsnet ].

Results were generally promising.  Of the short-period variables observed 3 displayed distinct variation during the observing interval ( RW Tri , RV Tri , BX And ) and some the longer period variables showed good results e.g.  RU Peg , but the brightness of many of the Mira-type variables appear to have been significantly overestimated. (eg S Lac & S Peg), possibly due to discrepancy between visual estimates and my CCD estimates made without a IR Blocking filter.

[ The underlying purpose of this project is to gain experience in variable star work using CCD camera and practice and refine my techniques in order to attempt to detect the transiting Jupiter mass short period extrasolar planet.(HD 209458-b) which causes a 1.7% dimming of HD209458 every 3.5 days which lasts for about 3 hours. The dimming has been detected by Castellano and Laughlin using almost identical equipment to me (i.e 8" telescope and ST-7E CCD camera) ]

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RU PEG

Good results were obtained for RU Peg,  with data results consistent with magnitude trends on VSNET

Light Curve data for RU Peg  (Pegasus)

Animated GIF image showing reduction in brightness of RU Peg, between images on 2002-10-03 (Mag +11.4) and 2002-11-24 (Mag +12.6), an interval of  52 days.

2002-10-03  22:40h UT,   3 x 5 sec median combine, (#28065-67) 2002-11-24  20:21h UT,   3 x 5 sec median combine, (#32114-16)

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RX And

Animated GIF image showing 3 magnitude change in brightness of RX And from  2002-10-03 to 2002-11-24 [ Catalog data :  UGZ-type variable, period (14) days ]

Sequence of 4 CCD frames,  10 sec exposures taken on 2002-10-03 (#28200), 2002-11-07 (#30039), 2002-11-10 (#31008), 2002-11-24 (#32017)

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RW TRI

RW Tri, reference image, 15 sec exposure (north down)

2002-11-24  20:52h UT CCD Image, 15 sec exposure (2x2 binning) 11.4 x 7.6 arc min  (#32178)

Light Curve Data for RW TRI [ Catalog Data : EA/WD+Nl,  Period 5.565 hours , 12.5 to 15.6 range]

15 sec exposures taken in groups of 3 at approximately 25 minute intervals 2002-11-24

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RV TRI

RV Tri, reference image

2002-11-24  21:00h UT CCD Image, 15 sec exposure (2x2 binning) 11.4 x 7.6 arc min  (#32191)

Light Curve Data for RV TRI [ Catalog Data : EA/SD ,  Period 18.088 hours, 11.5 to 13.3 range ]

15 sec exposures taken in groups of 3 at  approximately 25 minute intervals, 2002-11-24

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BX AND

BX And (Andromeda) reference image, 5 sec exposure (north down)

2002-11-24  21:07h UT CCD Image, 1 5 sec exposure (2x2 binning) 11.4 x 7.6 arc min  (#32201)

Light Curve Data for BX AND [ Catalog Data : EW/DW:  Period 14.623 hours, 8.9 to 9.57 range ]

5 sec exposures taken in groups of 3 at approximately 25 minute intervals 2002-11-24

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S LAC

S Lac (Lacerta) reference image from 2002-10-03, 10 sec exposure (north down)

2002-10-02  23:06h UT CCD Image, 3 x 10 sec exposure (2x2 binning) 11.4 x 7.6 arc min  (#28119-21)

Light Curve Data for S Lac Showing noticable discrepancy between my CCD magnitude estimates and VSNET data (Is this due to significant IR (Infra-red) from S Lac -  I'm not using any IR blocking filter)

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S PEG

S Peg (Pegasus) reference image from 2002-10-03,  5 sec exposure (north down)

2002-10-02  22:21h UT CCD Image, 3 x 5 sec exposure (2x2 binning) 11.4 x 7.6 arc min  (#28026-28)

Light Curve Data for S Peg Showing noticable discrepancy between my CCD magnitude estimates and VSNET data (Is this due to significant IR (Infra-red) from S Peg -  I'm not using any IR blocking filter)

This page shows results of variable star monitoring from 2002-10-03 till 2002-11-24.  The Project has continued beyond this data and rough light curves for period up until Dec 2002  is shown on Variable Stars Project Page. 

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