Einstein Probe

Einstein Probe

Einstein Probe artist impression
Names	Aiyinsitan Tanzhen
Mission type	Space observatory
Operator	CAS, ESA
COSPAR ID	2024-007A
SATCAT no.	58753
Website	ep.bao.ac.cn/ep/
Mission duration	3 years (planned) 3 months and 18 days (ongoing)
Spacecraft properties
Spacecraft	Einstein Probe
Bus	Phoenix-Eye-2
Manufacturer	CAS
Launch mass	1,450 kg (3,200 lb)[1]
Dimensions	3 × 3.4 m (9.8 × 11.2 ft)
Start of mission
Launch date	9 January 2024, 07:02 UTC[2]
Rocket	Long March 2C[2]
Launch site	Xichang LC-3
Contractor	CASC
Orbital parameters
Reference system	Geocentric orbit
Regime	Low Earth orbit
Perigee altitude	581 km
Apogee altitude	596 km
Inclination	29°
Period	96 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

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

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

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]

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

References

Further reading

• Yuan, Weimin; Zhang, Chen; Chen, Yong; Ling, Zhixing (2022). "The Einstein Probe Mission". Handbook of X-ray and Gamma-ray Astrophysics. pp. 1–30. arXiv:2209.09763. doi:10.1007/978-981-16-4544-0_151-1. ISBN 978-981-16-4544-0.

External links

Operating

Radio and Microwave	NCLE (since 2018) Solar Orbiter (since 2020) STEREO (since 2006) Queqiao (since 2018) Wind (since 1994) Queqiao 2 (since 2024)
Infrared	James Webb (since 2022) Odin (since 2001) SOLAR (since 2008) WISE (since 2009)
Optical	Aoi (since 2018) Astrosat (since 2015) BRITE constellation (since 2013) CHASE (since 2021) CHEOPS (since 2019) DSCOVR (since 2015) Euclid (since 2023) Hayabusa2 (since 2021) Gaia (since 2013) HiRISE (since 2005) Hubble (since 1990) Hinode (Solar-B) (since 2006) NEOSSat (since 2013) Odin (since 2001) SDO (since 2010) SOHO (since 1995) SOLAR (since 2008) Swift (since 2004) TESS (since 2018)
Ultraviolet	Aditya-L1 (since 2023) ASO-S (since 2022) Astrosat (since 2015) Hibari (since 2021) Hinode (Solar-B) (since 2006) IRIS (since 2013) SDO (since 2010) SOHO (since 1995) SOLAR (since 2008) Solar Orbiter (since 2020) STEREO (since 2006) Swift (since 2004)
X-ray and Gamma-ray	AGILE (since 2007) CALET (since 2015) Chandra (AXAF) (since 1999) DAMPE (since 2015) Einstein Probe (since 2024) HXMT (Insight) (since 2017) INTEGRAL (since 2002) Fermi (since 2008) GECAM (since 2020) IXPE (since 2021) Spektr-RG (since 2019) Swift (since 2004) Max Valier Sat (since 2017) MAXI (since 2009) MinXSS-2 (since 2018) NICER (since 2017) NuSTAR (since 2012) LEIA (since 2022) XRISM (since 2023) XPoSat (since 2024) XMM-Newton (since 1999)
Other (particle or unclassified)	ACE (since 1997) AMS-02 (since 2011) CALET (since 2015) DAMPE (since 2015) IBEX (since 2008) ISS-CREAM (since 2017) Mini-EUSO (since 2019) SOHO (since 1995) Solar Orbiter (since 2020) STEREO (since 2006)

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