|
Sky Conditions Chart (S112) |
Notice
|
Back to Top
As part of an ongoing project examining the variability in Delta Cepheid, further image sets of the variable star Delta Cepheid were recording during the observing sessions on 2006-01-30 and 2006-01-31. A revised quality control step was applied to Oct 2005- Jan 2006 dataset in order to reject less reliable measurements. Previously rejection was based on dropping points were applied Zero Point offset of Reference Star exceeded a specific amount. The new rejection method is based on dropping points where the control magnitude falls outside of a specified tolerance ( +/- 0.05).
The first two figures below show the full datasets in B & V bands are shown in first two figures below (best data highlighted). Three further figures show just validated V, B & B-V data plotted against phase assuming a period of 5.366341 days.
V Band Magnitude estimates for Delta
Cepheid |
B Band Magnitude estimates for Delta
Cepheid |
V Band Magnitude estimates for Delta
Cepheid |
B Band Magnitude estimates for Delta
Cepheid |
Magnitude and colour variation in Delta
Cepheid based on observations on 13 observing sessions between 2005-10-02 and 2006-01-31. |
Further observations will be made during
future sessions in order to fully refine the light curve |
Back to Top
Frost slugs appeared during the previous session
(2006-01-30) and whilst the dessicator was renewed and reinserted in the ST7
camera before the session of 2006-01-31,, the moisture has still not fully been
absorbed and further frost slugs showed during the session (through noted
to gradually shrink through the session). By the next session
(2006-02-02) the moisture had all been absorbed and no frost/ice problems
occurred.
(Previous problems with frost slugs or ice effects occurred 2005-08-05,
2003-11-21
Frost slugs at CCD temperature of -30 degC | ||
Frost slugs and adjacent
icy light reflections are visible in this image. Black/white range set to highlight the light reflections from icy frost slug patches. |
||
Frost slugs and icy light reflections still visible with 'Normal' black-white range |
||
Adjusting black-white range removes the majority of frost slugs/light reflections, but at the expense of reducing the visibility of dimmest stars. |
||
Adjusting black-white
range allows dim stars to be seen, but at the expense of showing frost slug outlines. |
Back to Top
This Web Page: | CCD Image Notes - (2006-01-31) |
Last Updated : | 2015-05-16 |
Site Owner : | David Richards |
Home Page : | David's Astronomy Web Site |