PDS 70

The protoplanetary disk of PDS 70 with PDS 70b (bottom-left) and PDS 70c (right)
Observation dataEpoch J2000      Equinox J2000
Constellation	Centaurus
Right ascension	14h 08m 10.15455s[1]
Declination	−41° 23′ 52.5733″[1]
Apparent magnitude (V)	12[2]
Characteristics
Evolutionary stage	Pre-main-sequence(T Tauri)
Spectral type	K7[3]
U−B color index	0.71[4]
B−V color index	1.06[4]
Astrometry
Radial velocity (Rv)	0.74±3.22[1] km/s
Proper motion (μ)	RA: −29.697mas/yr[1]Dec.: −24.041mas/yr[1]
Parallax (π)	8.8975±0.0191 mas[1]
Distance	366.6 ± 0.8 ly (112.4 ± 0.2 pc)
Details
Mass	0.901+0.067−0.060[5] M☉
Radius	1.14±0.03[6] R☉
Luminosity	0.35±0.09[3] L☉
Temperature	4247+31−39[6] K
Rotation	~50[7] days
Rotational velocity (v sin i)	~10[7] km/s
Age	5.4±1.0[3] Myr
Other designations
V1032 Cen, 2MASS J14081015−4123525, IRAS 14050−4109
Database references
SIMBAD	data

PDS 70 (V1032 Centauri) is a very young T Tauri star in the constellation Centaurus. Located 370 light-years (110 parsecs) from Earth, it has a mass of 0.76 M_☉ and is approximately 5.4 million years old.^[3] The star has a protoplanetary disk containing two nascent exoplanets, named PDS 70b and PDS 70c, which have been directly imaged by the European Southern Observatory's Very Large Telescope, as well as a third unconfirmed protoplanet. PDS 70b was the first confirmed protoplanet to be directly imaged.^[8][9][3]

The "PDS" in this star's name stands for Pico dos Dias Survey, a survey that looked for pre-main-sequence stars based on the star's infrared colors measured by the IRAS satellite.^[11] PDS 70 was identified as a T Tauri variable star in 1992, from these infrared colors.^[12] PDS 70's brightness varies quasi-periodically with an amplitude of a few hundredths of a magnitude in visible light.^[13] Measurements of the star's period in the astronomical literature are inconsistent, ranging from 3.007 days to 5.1 or 5.6 days.^[14][15]

The protoplanetary disk around PDS 70 was first hypothesized in 1992^[16] and fully imaged in 2006 with phase-mask coronagraph on the VLT.^[2] The disk has a radius of approximately 140 au. In 2012 a large gap (~65 au) in the disk was discovered, which was thought to be caused by planetary formation.^[7][17]

The gap was later found to have multiple regions: large dust grains were absent out to 80 au, while small dust grains were only absent out to the previously-observed 65 au. There is an asymmetry in the overall shape of the gap; these factors indicate that there are likely multiple planets affecting the shape of the gap and the dust distribution.^[18]

The James Webb Space Telescope has been used to detect water vapor in the inner part of the disk, where terrestrial planets may be forming.^[19][20]

จากผลการวิจัยที่ตีพิมพ์ในปี 2018 พบว่าดาวเคราะห์ดวงหนึ่งในจานหมุนชื่อ PDS 70 b ได้รับการถ่ายภาพด้วยเครื่องถ่ายภาพดาวเคราะห์ SPHERE ที่กล้องโทรทรรศน์ขนาดใหญ่มาก (VLT) ^{[ 3 ] [ 9 ]} ดาวเคราะห์ดวงนี้คาดว่ามีมวลมากกว่า ดาวพฤหัสบดีหลายเท่า[ ^{24 ] และ}เชื่อว่ามีอุณหภูมิประมาณ 1,200  K (930  °C ; 1,700  °F ) ^{[ 25 ]}และมีชั้นบรรยากาศที่มีเมฆ^{[ 9 ]}วงโคจรของมันมีรัศมี โดยประมาณ 20.8  AU (3.11 พันล้านกิโลเมตร) ^{[ 24 ]} และ ใช้เวลาประมาณ 120 ปีในการโคจรรอบหนึ่ง รอบ ^{[ 22 ]}

สเปกตรัมการปล่อยของดาวเคราะห์ PDS 70 b เป็นสีเทาและไม่มีลักษณะเฉพาะ และไม่มีการตรวจพบโมเลกุลชนิดใดเลยจนถึงปี 2021 ^{[ 26 ]}

ดาวเคราะห์ดวงที่สองซึ่งมีชื่อว่า PDS 70 c ถูกค้นพบในปี 2019 โดยใช้สเปกโตรกราฟสนามรวม MUSE ของ VLT [ 27 ^{]ดาวเคราะห์ดวง}นี้โคจรรอบดาวฤกษ์แม่ที่ระยะห่าง 34.3  AU (5.13 พันล้านกิโลเมตร) ซึ่งไกลกว่า PDS 70 b ^{[ 24 ]} PDS 70 c อยู่ใน การโคจรแบบใกล้เคียง 1:2 กับ PDS 70 b ซึ่งหมายความว่า PDS 70 c โคจรรอบเกือบหนึ่งรอบทุกครั้งที่ PDS 70 b โคจรรอบเกือบสองรอบ^{[ 27 ]}

การสร้างแบบจำลองคาดการณ์ว่า PDS 70 b ได้รับ จานรอบดาวเคราะห์ (CPD) ของตัวเอง^{[ 8 ] [ 28 ]} CPD ได้รับการสนับสนุนจากการสังเกตการณ์ครั้งแรกในปี 2019 ^{[ 29 ]}อย่างไรก็ตาม ในปี 2020 มีหลักฐานที่แสดงให้เห็นว่าข้อมูลปัจจุบันสนับสนุนแบบจำลองที่มีองค์ประกอบเดียวของดาวเคราะห์^{[ 30 ]}อัตราการสะสมมวลถูกวัดได้ว่ามีอย่างน้อย5 • 10 ⁻⁷เท่าของมวลดาวพฤหัสบดีต่อปี^{[ 31 ]}การศึกษาในปี 2021 ด้วยวิธีการและข้อมูลที่ใหม่กว่าชี้ให้เห็นอัตราการสะสมมวลที่ต่ำกว่า(1.4 ± 0.2) × 10 ⁻⁸  M _Jต่อปี^{[ 32 ]}ยังไม่ชัดเจนว่าจะเชื่อมโยงผลลัพธ์เหล่านี้เข้าด้วยกันและกับแบบจำลองการสะสมตัวของดาวเคราะห์ที่มีอยู่ได้อย่างไร การวิจัยในอนาคตเกี่ยวกับกลไกการสะสมตัวและการผลิตการปล่อย Hα ควรจะให้ความชัดเจน^{[ 33 ]}

In July 2019, astronomers using the Atacama Large Millimeter Array (ALMA) reported the first-ever detection of a moon-forming circumplanetary disk. The disk was detected around PDS 70 c, with a potential disk observed around PDS 70 b.^[34][35][36] The two planets and the superposition of PDS 70 c and the protoplanetary disk was confirmed by Caltech-led researchers using the W. M. Keck Observatory in Mauna Kea, whose research was published in May 2020.^[37] An image of the circumplanetary disk around PDS 70 c separated from the protoplanetary disk was finally confirming the circumplanetary disk and was published in November 2021.^[38]

In 2025 two studies found variable accretion from the variable H-alpha emission line for both planet b and c. One work used Magellan/MagAO-X and the other used Hubble. Planet b did show a general fading trend, with a decrease in brightness by a factor of 4.6. Planet c did increase in brightness by a factor of 2.3 between 2023 and 2024. The MagAO-X observations also suggest in reasonably good agreement with a predicted scattered light model of a CPD that both planets are surrounded by a compact disk with a radius of about 3 astronomical units.^[39][40]

VLT/SPHERE observations showed a third object 0.12 arcseconds from the star. Its spectrum is very blue, possibly due to star light reflected in dust. It could be a feature of the inner disk. The possibility does still exist that this object is a planetary mass object enshrouded by a dust envelope. For this second scenario the mass of the planet would be on the order of a few tens M_🜨.^[22] JWST NIRCam observations also detected this object. It is located at around 13.5 AU and if it is a planet, it would be in a 1:2:4 mean-motion resonance with the other protoplanets.^[41] In 2025 a team combined VLT/SPHERE, VLT/NaCo, VLT/SINFONI and JWST/NIRcam observations and detected Keplerian motion of the candidate. The planet candidate is detected over nine epochs ranging nine years of observations. The orbit could be in resonance with the other planets. The spectrum in the infrared is mostly consistent with the star PDS 70, but beyond 2.3 μm an infrared excess was detected. This excess could be produced by the thermal emission of the protoplanet, by circumplanetary dust, variability or contamination. The source may not be a point-like source. The source is therefore interpreted as an outer spiral wake from protoplanet d with a dusty envelope. A feature of the inner disk is an alternative explanation of candidate d.^[21] Planet-disk simulations suggest PDS 70 "d"'s 1:2:4 mean-motion resonance locking with b and c will allow the system to remain stable in the current configuration for at least a billion years, long after the disk is fully dissipated.^[42]

Another candidate, called "CC3" is consistent with a planet at 5.6 AU, but could also be a PSF artifact. It could also be a clump and the same phenomenon as planet "d" from JWST and "CC1" from Hubble, because all three candidates have the a similar position angle.^[39]

In a 2026 study, the planet d has not been re-detected at the expected position despite the sensitivity of VLTI/GRAVITY+, suggesting that it should be a dust clump instead of a planet. This situation is similar to that of the Fomalhaut star (see Fomalhaut b).^[43]

In July 2023, the likely detection of a cloud of debris co-orbital with the planet PDS 70 b was announced. This debris is thought to have a mass 0.03-2 times that of the Moon, and could be evidence of a Trojan planet or one in the process of forming.^[44][45]

• 
  ALMA image of a resolved circumplanetary disk around exoplanet PDS 70c
• 
  Hubble image of PDS 70. This is only the second multi-planet system to be directly imaged.
• 
  James Webb Space Telescope spectrum of PDS 70, detecting water in the terrestrial region of the protoplanetary disk

• List of brightest stars
• List of nearest bright stars
• Lists of stars
• Historical brightest stars

• Video (1:20) − Moon-forming Circumplanetary disc on YouTube (ESO; July 2021)