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Einstein Probe

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Einstein Probe
Einstein Probe artist impression
NamesAiyinsitan Tanzhen
Mission typeSpace observatory
OperatorCAS, ESA
COSPAR ID2024-007A Edit this at Wikidata
SATCAT no.58753
Websiteep.bao.ac.cn/ep/
Mission duration3 years (planned)
1 year and 18 days (ongoing)
Spacecraft properties
SpacecraftEinstein Probe
BusPhoenix-Eye-2
ManufacturerCAS
Launch mass1,450 kg (3,200 lb)[1]
Dimensions3 × 3.4 m (9.8 × 11.2 ft)
Start of mission
Launch date9 January 2024, 07:02 UTC[2]
RocketLong March 2C[2]
Launch siteXichang LC-3
ContractorCASC
Orbital parameters
Reference systemGeocentric orbit
RegimeLow Earth orbit
Perigee altitude581 km
Apogee altitude596 km
Inclination29°
Period96 minutes
Instruments
Wide-field X-ray Telescope (WXT)
Follow-up X-ray Telescope (FXT)

Einstein Probe Logo

The Einstein Probe (EP) is an X-ray space telescope mission by Chinese Academy of Sciences (CAS) in partnership with European Space Agency (ESA) and the Max Planck Institute for Extraterrestrial Physics (MPE) dedicated to time-domain high-energy astrophysics.[3][4] The primary goals are "to discover high-energy transients and monitor variable objects".[5] The telescope was launched by a Long March 2C rocket from the Xichang Satellite Launch Centre in China, on 9 January 2024, at 07:03 UTC.[6]

Scientific objectives

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The primary science objectives are:[7]

  1. Identify inactive black holes to study how matter is precipitated there by detecting the transient events that take the form of X-ray flares;
  2. Detect the electromagnetic counterpart of events triggering gravitational waves such as the merger of neutron stars which will be discovered by the next generation of gravitational wave detectors;
  3. Carry out permanent monitoring of the entire sky to detect the various transient phenomena and carry out measurements of known variable X-ray sources.

Instruments

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Einstein Probe carries 2 scientific instruments: the Wide-field X-ray Telescope (WXT), and the Follow-up X-ray Telescope (FXT).[8] Both telescopes utilize X-ray focusing optics.

  • Wide-field X-ray Telescope (WXT): WXT has a new optics design, called "lobster-eye", that has wider field of view.[4][8] "Lobster-eye" optics was first tested by the Lobster Eye Imager for Astronomy (LEIA) mission, launched in 2022.[4][9][10] WXT consists of 12 Lobster-eye optics sensor modules, together creating a very large instantaneous field-of-view of 3600 square degrees. The nominal detection bandpass of WXT is 0.5~4.0 keV. Each module weighs 17 kg and has an electrical power consumption of just under 13 W. With the peripherals, the entire telescope weighs 251 kg and has a power consumption of 315 W.
  • Follow-up X-ray Telescope (FXT): FXT has optics adopted from eROSITA, "the mirror module consists of 54 nested Wolter mirrors with a focal length of 1600 mm and an effective area of greater than 300 cm2 at 1.5 keV."[8]

The probe weights 1450 kg and is 3-by-3.4 metres.[4]

Launch

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Einstein Probe was launched on 9 January 2024, at 07:03 UTC by a Long March 2C rocket from the Xichang Satellite Launch Centre in China, and successfully placed in low Earth orbit at an altitude of 600 km[2] and an inclination of 29 degrees, giving an orbital period of 96 minutes.[11]

Findings

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CAS reported that EP "performs as expected in the first month".[12] The probe detected fast X-ray transient EP240315a,[13] and bright X-ray flares EP240305a[14] and EPW20240219aa.[15]

On 15 March 2024, the Einstein Probe detected EP240315a, a soft X-ray burst from 12.5 billion light-years away, lasting over 17 minutes—the longest duration observed from such an ancient explosion. Linked to gamma-ray burst GRB 240315C, this event showed a six-minute delay between X-rays and gamma rays, never observed before. ESA notes that these findings challenge existing gamma-ray burst models.[16][17][18]

See also

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References

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  1. ^ "Einstein Probe factsheet". ESA. Retrieved 10 January 2024.
  2. ^ a b c "Einstein Probe lifts off on a mission to monitor the X-ray sky". www.esa.int.
  3. ^ "Einstein Probe in a nutshell". www.esa.int. Retrieved 28 December 2023.
  4. ^ a b c d "Einstein Probe factsheet". www.esa.int. Retrieved 28 December 2023.
  5. ^ "Einstein Probe Time Domain Astronomical Information Center". ep.bao.ac.cn. Retrieved 28 December 2023.
  6. ^ Jones, Andrew (January 9, 2024). "China launches "lobster eye" Einstein Probe to unveil mysteries of X-ray universe". spacenews.com.
  7. ^ "Science Objectives Overview". Einstein Probe. Retrieved 14 January 2024.
  8. ^ a b c "EinsteinProbe". www.mpe.mpg.de. Retrieved 28 December 2023.
  9. ^ "Einstein Probe Time Domain Astronomical Information Center". ep.bao.ac.cn. Archived from the original on 28 December 2023. Retrieved 28 December 2023.
  10. ^ Jones, Andrew (November 25, 2022). "China tests novel 'lobster eye' X-ray telescope for observing cosmic events". Space.com.
  11. ^ "Technical details for satellite EINSTEIN PROBE". N2YO.com - Real Time Satellite Tracking and Predictions. Retrieved 2024-03-07.
  12. ^ "Time Domain Astronomical Information Center". ep.bao.ac.cn. Retrieved 13 April 2024.
  13. ^ "Time Domain Astronomical Information Center". ep.bao.ac.cn. Retrieved 13 April 2024.
  14. ^ "Time Domain Astronomical Information Center". ep.bao.ac.cn. Retrieved 13 April 2024.
  15. ^ "Time Domain Astronomical Information Center". ep.bao.ac.cn. Retrieved 13 April 2024.
  16. ^ "Einstein Probe detects puzzling cosmic explosion". www.esa.int.
  17. ^ Liu, Y.; et al. (January 23, 2025). "Soft X-ray prompt emission from the high-redshift gamma-ray burst EP240315a". Nature Astronomy: 1–13. arXiv:2404.16425. doi:10.1038/s41550-024-02449-8 – via www.nature.com.
  18. ^ Ricci, Roberto; Troja, Eleonora; Yang, Yu-Han; Yadav, Muskan; Liu, Yuan; Sun, Hui; Wu, Xuefeng; Gao, He; Zhang, Bing; Yuan, Weimin (2025). "Long-term Radio Monitoring of the Fast X-Ray Transient EP 240315a: Evidence for a Relativistic Jet". The Astrophysical Journal Letters. 979 (2): L28. arXiv:2407.18311. doi:10.3847/2041-8213/ad8b3f.

Further reading

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