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!!!