In the
Berea College Observatory
Ramesh AdhikariJimmy Rop William Chase ColeDr. Tracy Hodge
Objectives of the Project:
* To check the effectiveness of the instruments in the observatory.
* To study the procedure of finding the clear and detailed image of the target star.
* To observe the movement of the star of over a specified period of the time.
* To find out the magnitude of the variables such as RR Lyra and AF Cyg.
* To study the period of RR Lyra with the help of the light curve.
Variable Stars:
*Changes in Brightness
*Intrinsic Variables
•Extrinsic Variable
RR Lyrae:
Classification: Pulsating Variable
Location: Globular Cluster
Period: 0.2 to 2 days
Luminosity: 45L sun appx.
WHY?
Opacity of Helium.Neutral Helium have opacityRadiation gets trapped.Star Shrinks.Energy due to radiation ionizes Heluim.Opacity decreasesRadiation escapes out on the atmosphereStar expands.
Telescope specification:
-16 inch telescope that was constructed by DFM engineering based in New Jersey
-The telescope is driven by a mechanical motor and a computer attached.
Berea College Observatory:
S-Big STS camera:
-2 CCD detectors-Frame Resolution of 765 x 510 pixels-Mounted in close proximity and focused at the same plane
-Remote guiding head port-Electro- mechanical shutter-16 bit analog to digital convertor-Regular Temperature control
Flat Field:Median of the sky frames.Corrects the irregularities I the optical system.Divides out the non-uniformity of the sky.
a) Get the median of the Flatsb) Subtract the 10s dark current image arithmeticc) Divide by 10d) Normalize to 1
Dark Frame:a) Measures the electronic noise in the camera that
needs to be subtracted out.b) Shutter closed.
Calculations:
Magnitude of a Star (m) = -2.5log(I)
Initial Star Image – Dark Frame (At the same time)
For any star image: -------------------------------------------------------------------------------------
Master Flat
Further image reduction was done using Mira software to get the magnitude
of the image of the star.
Working with Star Image
Actual magnitude = Instrumental magnitude + constant
Constant = Actual Magnitude - Instrumental magnitude
RR Lyra (m) = RR Instrumental + constant
RR Lyra(m) = RR Instrumental + SAO Actual Magnitude – SAO Instrumental magnitude
Phase: Time difference between observation/ period of the star
Photographic Image of RR Lyra
Fits image of RR Lyra
http://foto.star-shine.ch/details.php?image_id=426
Conclusions:
. We were able to use the instruments in the observatory effeciently than during the last summer.
. Provided enough time, we could get detail information on the variable stars and continue various characteristics related to them.
. The result we obtained at the end of the research was comparable to the previous data and graphs.
. It would have been better if Berea would have no light, at least during the clear night!!!