Einstein Probe Explained

Einstein Probe
Names List:	Aiyinsitan Tanzhen
Mission Type:	Space observatory
Operator:	CAS, ESA
Cospar Id:	2024-007A
Satcat:	58753
Mission Duration:	3 years (planned) (ongoing)
Spacecraft:	Einstein Probe
Spacecraft Bus:	Phoenix-Eye-2
Manufacturer:	CAS
Launch Mass:	^[1]
Launch Date:	9 January 2024, 07:02 UTC
Launch Rocket:	Long March 2C
Launch Site:	Xichang LC-3
Launch Contractor:	CASC
Orbit Reference:	Geocentric orbit
Orbit Regime:	Low Earth orbit
Orbit Periapsis:	581 km
Orbit Apoapsis:	596 km
Orbit Inclination:	29°
Orbit Period:	96 minutes
Apsis:	gee
Instruments:	Wide-field X-ray Telescope (WXT) Follow-up X-ray Telescope (FXT)
Insignia:	File:Einstein Probe logo.png
Insignia Caption:	Einstein Probe Logo
Insignia Size:	200px

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.^{[2] [3]} The primary goals are "to discover high-energy transients and monitor variable objects".^[4] 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.^[5]

Scientific objectives

The primary science objectives are:^[6]

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

Einstein Probe carries 2 scientific instruments: the Wide-field X-ray Telescope (WXT), and the Follow-up X-ray Telescope (FXT).^[7] 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.^{[3] [7]} "Lobster-eye" optics was first tested by the Lobster Eye Imager for Astronomy (LEIA) mission, launched in 2022.^{[3] [8] [9]} 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."^[7]

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

Launch

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^[10] and an inclination of 29 degrees, giving an orbital period of 96 minutes.^[11]

First results

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]

See also

• Timeline of artificial satellites and space probes
• List of things named after Albert Einstein
• X-ray astronomy
• List of space telescopes#X-ray

Further reading

• Book: Yuan . Weimin . Zhang . Chen . Chen . Yong . Ling . Zhixing . Handbook of X-ray and Gamma-ray Astrophysics . The Einstein Probe Mission . 2022 . 1–30 . 10.1007/978-981-16-4544-0_151-1 . 2209.09763 . 978-981-16-4544-0 .

External links

• at NAOC, CAS.
• Einstein Probe at ESA.int
• Einstein Probe at MPE.MPG.de

Notes and References

1. Web site: Einstein Probe factsheet . 10 January 2024 . ESA.
2. Web site: Einstein Probe in a nutshell . www.esa.int . 28 December 2023 . en.
3. Web site: Einstein Probe factsheet . www.esa.int . 28 December 2023 . en.
4. Web site: Einstein Probe Time Domain Astronomical Information Center . ep.bao.ac.cn . 28 December 2023.
5. Web site: China launches “lobster eye” Einstein Probe to unveil mysteries of X-ray universe. Andrew . Jones. January 9, 2024. spacenews.com.
6. Web site: 14 January 2024. en. Science Objectives Overview . Einstein Probe.
7. Web site: EinsteinProbe . www.mpe.mpg.de . 28 December 2023 . en.
8. Web site: Einstein Probe Time Domain Astronomical Information Center . ep.bao.ac.cn . 28 December 2023 . 28 December 2023 . https://web.archive.org/web/20231228121939/https://ep.bao.ac.cn/ep/cms/article/view?id=91 . dead .
9. Web site: China tests novel 'lobster eye' X-ray telescope for observing cosmic events. Andrew . Jones. November 25, 2022. Space.com.
10. Web site: Einstein Probe lifts off on a mission to monitor the X-ray sky. www.esa.int.
11. Web site: Technical details for satellite EINSTEIN PROBE . 2024-03-07 . N2YO.com - Real Time Satellite Tracking and Predictions.
12. Web site: Time Domain Astronomical Information Center . ep.bao.ac.cn . 13 April 2024.
13. Web site: Time Domain Astronomical Information Center . ep.bao.ac.cn . 13 April 2024.
14. Web site: Time Domain Astronomical Information Center . ep.bao.ac.cn . 13 April 2024.
15. Web site: Time Domain Astronomical Information Center . ep.bao.ac.cn . 13 April 2024.