The upper point on the main sequence which is the most densely populated with stars where the red giants seem to begin is called the turnoff point; the exact location of turnoff point indicates the age of the cluster.
Deriving the distance and age of M52
We have already identified main sequence, turnoff point, and giant red for M52 shown in figure by comparing with Figure 1. A best fit line this will help to find the distance to open cluster M52 by using the techniques of best fit line.
In table 1 (The Open University, 2015, p.11) the value for colour excess E (B-V) = 0.65 noted for the M52 cluster; E(B-V) indicates an interstellar extinction which is caused by gas and dust in the line of sight resulting in dimmer magnitudes of stars than …show more content…
The turnoff point located 11.4 indicating the rough age of the M52 cluster.
Deriving the distance and age of M39
In comparison with Figure 1 the main sequence, turnoff point, and giant red for M39 are identified and clearly shown in figure 3.
As before the colour excess for M39 is 0.01 resulting Av = 3× 0.01 = 0.03. The apparent magnitude mv is 8.8 and the absolute magnitude Mv is +0.70. The uncertainty in the main sequence recorded the maximum value 15.00 and minimum value 9.00 in Y-axis which gives 15.00-9.00 = ± 6.00. Now we need to plug all known values in equation 1 to calculate distance in parsec as below:
d = 10 (8.8-0.70+5-0.03) /5 = 10 2.6 = 398.10 ± 6.00 parsec= 392.10 parsec × (3.261 light year/ 1 parsec) = 1278.86 light year= 1.279 × 103 light year
The published distance for M39 is 326 parsec (Mavers, 1940). To calculate the percentage error, using equation 2 we get
Gives us percentage error = ((392.10-326)/326) ×100
Percentage error = 20.27 %. The turnoff point located at 8.8 indicating the rough age of the M39 cluster. Also, points lying lower than the 16th magnitude below to the left of the Main Sequence for M39 are considered to be interpolar …show more content…
For example this software removes bad pixels by interpolating using adjacent pixel values. However, interpolated value is only an estimated version which is only a partial correction and may lead to an error. Also, we may misidentified target stars with a close companion stars and it is expected that the exact location for the star is not selected, and it is common to be confused with the variable stars and that’s why the error in distance of clusters aroused.
Above all, it is possible, published data was acquired in different settings such as taking long exposure time compare to our 30 second exposure time with the assistance of more sophisticated telescope than The Bradford Robotic telescope.
This project could have been improved by taking longer exposure, using larger sample of data, and using PIRATE facility for taking raw and calibrated frames for better
Deriving the distance and age of M52
We have already identified main sequence, turnoff point, and giant red for M52 shown in figure by comparing with Figure 1. A best fit line this will help to find the distance to open cluster M52 by using the techniques of best fit line.
In table 1 (The Open University, 2015, p.11) the value for colour excess E (B-V) = 0.65 noted for the M52 cluster; E(B-V) indicates an interstellar extinction which is caused by gas and dust in the line of sight resulting in dimmer magnitudes of stars than …show more content…
The turnoff point located 11.4 indicating the rough age of the M52 cluster.
Deriving the distance and age of M39
In comparison with Figure 1 the main sequence, turnoff point, and giant red for M39 are identified and clearly shown in figure 3.
As before the colour excess for M39 is 0.01 resulting Av = 3× 0.01 = 0.03. The apparent magnitude mv is 8.8 and the absolute magnitude Mv is +0.70. The uncertainty in the main sequence recorded the maximum value 15.00 and minimum value 9.00 in Y-axis which gives 15.00-9.00 = ± 6.00. Now we need to plug all known values in equation 1 to calculate distance in parsec as below:
d = 10 (8.8-0.70+5-0.03) /5 = 10 2.6 = 398.10 ± 6.00 parsec= 392.10 parsec × (3.261 light year/ 1 parsec) = 1278.86 light year= 1.279 × 103 light year
The published distance for M39 is 326 parsec (Mavers, 1940). To calculate the percentage error, using equation 2 we get
Gives us percentage error = ((392.10-326)/326) ×100
Percentage error = 20.27 %. The turnoff point located at 8.8 indicating the rough age of the M39 cluster. Also, points lying lower than the 16th magnitude below to the left of the Main Sequence for M39 are considered to be interpolar …show more content…
For example this software removes bad pixels by interpolating using adjacent pixel values. However, interpolated value is only an estimated version which is only a partial correction and may lead to an error. Also, we may misidentified target stars with a close companion stars and it is expected that the exact location for the star is not selected, and it is common to be confused with the variable stars and that’s why the error in distance of clusters aroused.
Above all, it is possible, published data was acquired in different settings such as taking long exposure time compare to our 30 second exposure time with the assistance of more sophisticated telescope than The Bradford Robotic telescope.
This project could have been improved by taking longer exposure, using larger sample of data, and using PIRATE facility for taking raw and calibrated frames for better