Photoelectric and Spectroscopic Observations Related to a Possible Optical Counterpart for Pulsar CP 1919+21

Area of Science:

• Astronomy and Astrophysics
• Pulsar Research
• Stellar Photometry

Background:

• Pulsars are rapidly rotating neutron stars emitting beams of electromagnetic radiation.
• Identifying the optical counterparts of pulsars is crucial for understanding their emission mechanisms and environments.
• The pulsar CP 1919+21 is a significant object in radio astronomy.

Purpose of the Study:

• To investigate the nature of celestial objects near the pulsar CP 1919+21.
• To determine if any nearby stars are associated with the radio source.
• To analyze the variability of potential optical counterparts.

Main Methods:

• Spectroscopic observations were conducted on two stars near CP 1919+21.
• Extensive photometric observations were performed on a region including the brighter star.
• Analysis of light curves to detect periodic variations.

Main Results:

• Spectroscopic observations were inconclusive for identifying the radio source.
• Photometric observations revealed an approximately sinusoidal variation in the brighter star.
• The observed period of variation was found to be double the pulsar's radio pulsation period.

Conclusions:

• The studied stars are not definitively identified as the source of radio pulses from CP 1919+21.
• The detected variability suggests a potential, albeit unusual, relationship between the star and the pulsar.
• Further investigation is warranted to understand the nature of this double-periodicity phenomenon.