David's Astronomy Pages CCD Images - Session 99 (2005-10-13) Images (S98)   Images (Main)   Home Page   Images (S100)

RR Lyrae - Variable Star

An alternating sequence of  V Filter (10s exposure) and B Filter (20s exposure) images were recorded over a 5.7  hour interval.  Image capture was via automated scripts, however occasional manual intervention was required to keep both RR Lryae and the reference star within field of view and on 4 occasions to remove dew which had formed on the front lens of the LX200 scope. Two breaks were also made in order to acquire image sets of Delta Cepheid and T Tauri.

The dataset records the rapid brightening of RR Lyrae over a 1.5 - 2 hour interval, followed by a gradual dimming as the star proceeded through its regular period. The timing of the rise recorded in this session and during the previous session (S98) seem to be consistent with the standard period of 0.56686776 days.
[More on RR Lyrae Photometric Analysis]

RR Lyrae (Lyra) [RR Lyrae (bottom left), reference star SAO 48408 (top right),  control star SAO 48415 ]
CCD  Image (at ~ Minimum) 10s exposure, V filter 2005-10-13  22:48h UT (#99409)	CCD  Image (at ~ Maximum) 10s exposure, V filter 2005-10-14  01:02h UT (#99693)
Magnitude Data (B & V Filters)
Goto RR Lyrae Photometric Analysis Notes

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Gamma Draconis - Star 

Gamma Draconis was the star that the English physicist Robert Hooke made the first 'modern' attempt to detect annual parallax in 1669. His attempt was unsuccessful, and it was not  the 1830's/1840 that Friedrich Wilhelm Bessel and other astronomers first correctly detected parallax using slightly closer stars (eg 61 Cygni).  The star is probably too far away for it to show a parallax that can be measured using amateur equipment.  However to check this a baseline astrometric measurement of Gamma Draconis' position was made.  This task was made difficult as the number of catalog stars directly around the star is limited.  To achieve an adequate plate solution the star was moved to one corner of CCD field of view. 

Astrometric solution of Gamma Draconis (Draco) at 2005-10-13  based on 8 USNOB stars, image scale 1.31 arc sec/pixel

CCD  Image  15s exposure, V filter 2005-10-13 19:29h UT (#99029)

Astrometry measurement of Gamma Draconis based on  4 images (#99029-32), 1x1 binning, 15s exposure

Date (UT) Star RA (epoch 2000) Dec (epoch 2000)   2005-10-13 19:30 Gamma Dra, HIP 87833 17h 56m 36.41s +/-0.02s 51d 29m 19.04s +/-0.14s

Errors bars at +/-1 SD

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Delta Cepheid - Variable Star (Cepheid)

Image sets of Delta Cepheid  & reference star SAO 34542 were recorded at around 20:15h UT,  23:05h UT (2005-10-13) and 02:25h UT (2005-10-14). Image sets comprised  7 sequences of  3 x 0.2s V & 3 x 0.6s B (alternated between Delta Cepheid & reference star)  These were analyzed using the methodology described under 2005-10-05 Notes, and combined with previous estimates

B Band Magnitude estimates for Delta Cepheid  from images between 2005-10-02 and 2005-10-14 (Reference Star SAO 34542, B mag +3.81)

Further observations will be made during future sessions  in order to further refine the light curve

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T Tauri - Variable Star

Image sets of T Tauri were recorded at around 23:40h UT (2005-10-13) and 02:45h UT (2005-10-14).  Image sets comprised  3 x 15s V and 3 x 60s B.

T Tauri & adjacent nebula NGC 1555 (Taurus) [ NGC 1555 also known as Hind's variable nebula)

CCD Image  1 20 sec exposure,  C Filter 2005-10-14 02:40 h UT  (#99920)

T Tauri Photometry Baseline

CCD Image  30 sec exposure,  V Filter 2005-10-13 23:39 h UT  (#99519)

Photometry  V & B  Bands

Further observations will be made during future sessions  in order to further refine the light / colour variation.

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Mars

Mars

CCD Colour Image (Approximate Colour) Red : 0.11s (R Filter), Green : 0.11s (V Filter) Blue : 0.3s (B Filter) 2005-10-14 02:47 h UT  (#99926, 29 & 35)

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