PSR B0943+10

Characteristics

The pulsar is estimated to be 5 million years old, which is relatively old for a pulsar. It has a rotational period of 1.0977 seconds and emits both radio waves and X-rays. Ongoing research at the University of Vermont discovered that the pulsar was found to flip roughly every few hours between a radio bright mode with highly organized pulsations and a quieter mode with rather chaotic temporal structure.

Moreover, the observations of the pulsar performed simultaneously with the European Space Agency's XMM-Newton X-ray observatory and ground-based radio telescopes revealed that it exhibits variations in its X-ray emission that mimic in reverse the changes seen in radio waves – the pulsar has a weaker non-pulsing X-ray luminosity during the radio bright mode and is actually brighter during the radio quiet mode emitting distinct X-ray pulses. Such changes can only be explained if the pulsar's magnetosphere (which may extend up to 52000 km from the surface) quickly switches between two extreme states. The change happens on a few seconds timescale, far faster than most pulsars. Despite being one of the first pulsars discovered, the mechanism for its unusual behavior is unknown.

In 2006, a research group from Peking University published a paper suggesting that the pulsar may actually be a low-mass quark star with mass around .

Claimed planetary system

In May 2014, the detection of periodic timing variations was reported that could be explained by two gas giant planets orbiting PSR B0943+10. A more recent analysis from 2019 found instead a single, five-Earth mass planet with an orbital period of 12 years.

However, all proposed planets were found to be doubtful in a 2025 publication, which suggest the observed variations are due to magnetospheric phenomena and spin-down oscillations. The planets reported in 2014 are classified as "deprecated", while the planet reported in 2019 is a "questionable candidate".

Notes

References

References

1. [https://exoplanet.eu/catalog/psr_b0943_10_c--6642/ "The Extrasolar Planets Encyclopaedia Planet PSR B0943+10 c"]
2. Zang, Bing. (2005). "An XMM-Newton Observation of the Drifting Pulsar B0943+10". Astrophysical Journal.
3. G.S. Mudur. (25 January 2013). "Pune telescope spots Jekyll & Hyde puzzle in sky". The Telegraph, India.
4. Shklovsky, Iosif. (1970). "Evrika-70". [[Molodaya Gvardiya (publisher).
5. (2012). "A Brief History of Radio Astronomy in the USSR. A Collection of Scientific Essays". Springer.
6. [http://simbad.u-strasbg.fr/simbad/sim-id?protocol=html&Ident=PSR%20B0943%2B10 PSR B0943+10 -- Pulsar] in [[SIMBAD]]
7. ESA. (25 January 2013). "Baffling pulsar leaves astronomers in the dark". [[Astronomy.com]].
8. Elizabeth Howell. (24 January 2013). "Weird Spinning Star Defies Explanation". [[Space.com]].
9. (2013). "Synchronous X-ray and Radio Mode Switches: A Rapid Global Transformation of the Pulsar Magnetosphere". Science.
10. Staff. (24 January 2013). "Chameleon Pulsar Dramatically Changes the Way It Shines". [[Sciencedaily.com]].
11. Yue, Y. L.. (2006). "Is PSR B0943+10 a low-mass quark star?". Astrophysical Journal.
12. [https://exoplanet.eu/catalog/psr_b0943_10_b--6641/ "The Extrasolar Planets Encyclopaedia Planet PSR B0943+10 b"]
13. (2014). "Detection of regular variations in the intensity and pulse time of arrival of the anomalous pulsar PSR B0943+10". Astronomy Reports.
14. (March 2025). "On the Number of Confirmed Pulsar Planets: The Rule of Six". [[The Astrophysical Journal]].
15. (2019-04-01). "A 12-Year Periodicity in the Pulse Arrival Times for the Pulsar PSR B0943+10". Astronomy Reports.