M. Alqadhi
Dr. Bret Lehmer
Investigating the Possible Suggested Binary System of the Cat’s Eye Nebula (NGC 6543)
Introduction and Background
In 1764, Messier observed an intriguing celestial object that is known today as the Dumbbell Nebula or M27 as Messier named it in his catalogue of unclear nebulous objects. As many other similar objects were observed, astronomer noticed their similarity to the disk of a planet and that explains the reason behind their name, Planetary Nebulae (PNe). However, the nature of these objects stayed mysterious until 1864 when William Huggins was able to obtain the first spectrum of a PN, the Cat’s Eye Nebula. This observation was the first step toward understanding the mysterious nature behind the evolution …show more content…
For such a star, the spectrum would be dominated by Blue-optical and UV lines, which make HST the best-qualified telescope to observe such line (He II) at = 4686 A. Therefore, I propose to conduct a 1ks STIS exposure time directly over the central star of NGC 6543. The goal of this observation is to address the question of whether NGC 6543 has another companion by showing that a Doppler shift could be …show more content…
However, taking the radial velocity to be a maximum (81.082 km s-1), an expected Doppler Shift would be z = 2.7e-4 depending on the relative movement of the star. For the line He II 4686 A, the expected shift would be 1.27 A, which means that He II 4686 A would be observed at = 4687.27 A if the star is moving away from us or at = 4684.73 A If the star is moving toward us. If we take another possibility where we observe the star at different orbital point e.g. 50 km s-1, we would expect to observe the line (He II 4686 A) shifted by 0.781 A. If the binary system truly exists, then detecting a Doppler shift could be possible unless we observe the star across our line of
Dr. Bret Lehmer
Investigating the Possible Suggested Binary System of the Cat’s Eye Nebula (NGC 6543)
Introduction and Background
In 1764, Messier observed an intriguing celestial object that is known today as the Dumbbell Nebula or M27 as Messier named it in his catalogue of unclear nebulous objects. As many other similar objects were observed, astronomer noticed their similarity to the disk of a planet and that explains the reason behind their name, Planetary Nebulae (PNe). However, the nature of these objects stayed mysterious until 1864 when William Huggins was able to obtain the first spectrum of a PN, the Cat’s Eye Nebula. This observation was the first step toward understanding the mysterious nature behind the evolution …show more content…
For such a star, the spectrum would be dominated by Blue-optical and UV lines, which make HST the best-qualified telescope to observe such line (He II) at = 4686 A. Therefore, I propose to conduct a 1ks STIS exposure time directly over the central star of NGC 6543. The goal of this observation is to address the question of whether NGC 6543 has another companion by showing that a Doppler shift could be …show more content…
However, taking the radial velocity to be a maximum (81.082 km s-1), an expected Doppler Shift would be z = 2.7e-4 depending on the relative movement of the star. For the line He II 4686 A, the expected shift would be 1.27 A, which means that He II 4686 A would be observed at = 4687.27 A if the star is moving away from us or at = 4684.73 A If the star is moving toward us. If we take another possibility where we observe the star at different orbital point e.g. 50 km s-1, we would expect to observe the line (He II 4686 A) shifted by 0.781 A. If the binary system truly exists, then detecting a Doppler shift could be possible unless we observe the star across our line of