Hicks Observatory Pictures and Results

As part of the PHY217 module, 2nd year astronomy undergraduates undertake a short observational practical using the 0.4m telescope on the top of the Hicks building.
Popular choices for projects are lightcurves of a Delta-Scuti pulsating variable star, open cluster colour-magnitude diagrams, lightcurves of cataclysmic variable systems and lightcurves showing asteroid rotation.
Some images and results from these projects follow below.

Delta-Scuti pulsating variables

A sequence of images of a Delta-Scuti pulsating variable star are taken, such that the period of pulsation can be measured from the changing stellar magnitude.
Image analysis of the sequence is usually undertaken with Christian Buil's Iris software.

GP And

A sequence of 378 CCD V filtered images, each of 20 seconds duration, were taken of the 10.8 (V) magnitude GP And delta-scuti pulsating variable star along with a non-variable comparison star on the night of 2011-10-28.
The raw image [north is up and east is to the left] is a typical frame from the sequence, with GP And marked.
The graph shows the produced lightcurve for just over a full period and shows the difference in V magnitude between the variable star and the non-variable star against time...
[click on an image to enlarge]

gpandgp_and

Open Clusters

Images of open clusters are taken and then are used to produce a colour-magnitude diagram.
By fitting isochrones to the colour-magnitude diagram, the age and distance of the cluster can then be calculated.

CCD images are taken with the 0.4m, usually through B and V filters, to create equal exposure length pairs which range from a few seconds to several hundreds of seconds.
By varying the exposure lengths, the differing magnitudes of the cluster members can be correctly exposed.

Subsequent analysis using SExtractor then produces flux values for each star within every image.

Each star is then cross-correlated within it's pair using a in-house written linux program to calculate corrected B and V magnitudes for that particular star from the calculated flux.
The magnitudes for each star are then plotted onto a colour-magnitude diagram (i.e. each point on the plot is a star) and isocrones can then be subsequently fitted to calculate the age and distance.
Note that the following colour-magnitude diagrams have been corrected for atmospheric exinction, but have not been corrected for interstellar extinction which may move points along the x-axis within the diagrams.

NGC869

Raw 30s B and V images [north is up and east is to the left] of the NGC869 open cluster
taken on the night of 2011-12-09 and the subsequent colour-magnitude diagram...
[click on an image to enlarge]

ngc869_v_30s_thngc869_v_30s_th ngc869

NGC7789

Raw 240s B and V images [north is up and east is to the left] of the central region of the NGC7789 open cluster
taken on the night of 2011-11-01 and the subsequent colour-magnitude diagram...
[click on an image to enlarge]

ngc7789ngc7789ngc7789

NGC6939

Raw 300s B and V images [north is up and east is to the left] of the NGC6939 open cluster
taken on the night of 2011-11-01 and the subsequent colour-magnitude diagram...
[click on an image to enlarge]

ngc6939ngc6939ngc6939

NGC884

Raw 300s B and V images [north is up and east is to the left] of the NGC884 open cluster
taken on the night of 2011-10-19 and the subsequent colour-magnitude diagram...
[click on an image to enlarge]

ngc884ngc884ngc884

NGC663

Raw 300s B and V images [north is up and east is to the left] of the NGC663 open cluster
taken on the night of 2010-10-20 and the subsequent colour-magnitude diagram...
[click on an image to enlarge]

ngc663ngc663ngc663

M52

Raw 300s B and V images [north is up and east is to the left] of the M52 open cluster
taken on the night of 2010-10-19 and the subsequent colour-magnitude diagram...
[click on an image to enlarge]

m52m52m52