| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 14h 07m 47.92976s [1] |
| Declination | −39° 45′ 42.7671″ [1] |
| Apparent magnitude (V) | 12.2–15.6 [2] |
| Characteristics | |
| Evolutionary stage | Pre-main sequence [3] |
| Spectral type | K5 IVe Li [3] [4] |
| Variable type | rotational T Tau and eclipsing [2] |
| Astrometry | |
| Radial velocity (Rv) | 5.904±0.151 [4] km/s |
| Proper motion (μ) |
RA: −23.108±0.015
mas/
yr
[1] Dec.: −21.048±0.017 mas/ yr [1] |
| Parallax (π) | 7.2351 ± 0.0140 mas [1] |
| Distance | 450.8 ± 0.9
ly (138.2 ± 0.3 pc) |
| Details | |
| Mass | Gaia DR3 with
magnetism:
[5] 0.977+0.023 −0.045 M☉ Gaia DR3 without magnetism: [5] 0.891+0.062 −0.144 M☉ Gaia DR2: [6]: 2 0.95±0.10 M☉ |
| Radius | 1.0661+0.0062 −0.0139 [7] R☉ |
| Luminosity | 0.3431+0.0067 −0.0064 [7] L☉ |
| Surface gravity (log g) | 4.302+0.0243 −0.0243 [7] cgs |
| Temperature | 4343+24 −29 [7] K |
| Metallicity [Fe/H] | −0.1903+0.0448 −0.0422 [7] dex |
| Rotation | 3.206±0.002 d [8]: 6 [a] |
| Rotational velocity (v sin i) | 14.6±0.4 [9] km/s |
| Age | ~16
[3] or 21.38+4.30 −7.60 [6]: 2 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
V1400 Centauri (known under its SuperWASP catalogue entry 1SWASP J140747.93−394542.6, or simply J1407) is a young, pre-main-sequence star that was eclipsed by a likely free-floating substellar object with a circumstellar disk or rings (known as J1407b or Mamajek's Object) in April–May 2007. With an age around 20 million years, the star is about as massive as the Sun and is located in the constellation Centaurus at a distance of 451 light-years away from the Sun. V1400 Centauri is a member of Upper Centaurus–Lupus subgroup of the Scorpius–Centaurus association, a group of young, comoving stars close to the Sun.
The discovery of J1407b's 2007 eclipse of V1400 Centauri was announced in 2012 by a team of astronomers led by Eric E. Mamajek, who directed an analysis of photometric data from the Super Wide Angle Search for Planets (SuperWASP) sky survey. Mamajek's team hypothesized that J1407b is a substellar object that could either be orbiting the star as a planet or binary companion, or is a gravitationally unbound object that coincidentally passed in front of the star. [3] Later studies have since found evidence disfavoring the bound companion hypothesis, which leaves the unbound hypothesis as the most likely explanation for J1407b's nature: no additional eclipses in V1400 Centauri have been observed after 2007 nor during 1890–1990, [6] [8] which leaves out very few possible orbits where the massive rings of J1407b can theoretically repeat eclipses of V1400 Centauri while being stable against the star's gravitational influence. [6]: 7
High-resolution imaging by the Atacama Large Millimeter Array (ALMA) in 2017 revealed a single faint object near V1400 Centauri, which could either be a young substellar object surrounded by a circumstellar disk, or a background galaxy. This faint object is far enough away from V1400 Centauri that it cannot be gravitationally bound to the star, which makes it a very likely candidate for J1407b. However, the faint object has only been observed once, so it is not yet confirmed whether it is a moving foreground object or a stationary background galaxy. If this faint object is a substellar object, then it would have a mass below 6 Jupiter masses, which would also make it a sub-brown dwarf or a rogue planet. [10]
Name and catalogue history
The star was first catalogued in the 1990s by the Hubble Guide Star Catalog, which found the star and measured its position in a pair of photographic plates taken in 1974 and 1979. [11] The star has been catalogued by other sky surveys, including the All Sky Automated Survey (ASAS), Two Micron All-Sky Survey (2MASS), Super Wide Angle Search for Planets (1SWASP), and the Wide-field Infrared Survey Explorer (WISE). [4] Typically in these catalogues, the star is given designations such as 1SWASP J140747.93–394542.6, which comprises the survey name followed by the star's location in equatorial coordinates. [4] As such designations can be unwieldy, researchers simply call the star "J1407". [3]: 5 [10] The star was given the official variable star designation V1400 Centauri in 2015, when it was added to the International Astronomical Union's General Catalogue of Variable Stars. [12]
Stellar properties
Location and age
V1400 Centauri is located in the constellation Centaurus, about 40 degrees south of the celestial equator. The most recent parallax measurements by the Gaia spacecraft indicate V1400 Centauri is located 450.8 ± 0.9 light-years (138.2 ± 0.3 parsecs) from the Sun. [1] Observations of V1400 Centauri's position over time have shown that it has a southwestward [b] proper motion consistent with that of the Scorpius–Centaurus association, an OB association of young stars with ages between 11–17 million years and distances between 380–470 ly (118–145 pc) from the Sun. [3]: 4 The Scorpius–Centaurus association is the nearest OB association to the Sun, and is believed to have formed out of a molecular cloud that has since been blown away by the stellar winds of the association's most massive stars. [13]: 236, 250
V1400 Centauri is closest to the Upper Centaurus–Lupus subgroup of the Scorpius–Centaurus association, which has an age range of 14–18 million years and distance range of 380–460 ly (115–141 pc).
[3]: 5-6 Given V1400 Centauri's similar distance and proper motion, it very likely belongs to the Scorpius–Centaurus association, which would mean it must be a young star within the age range of the Upper Centaurus–Lupus subgroup.
[3]: 5-6 A 2012 estimate of V1400 Centauri's age assumes it is equal to 16 million years,
[3]: 6 the mean age of the Upper Centaurus–Lupus subgroup, while a 2018 estimate from Gaia measurements puts the star's age at 21.38+4.30
−7.60 million years.
[6]: 2
Spectral type and physical characteristics
V1400 Centauri is a pre-main sequence star of spectral class K5 IVe Li. [4] [3]: 5 "K" means V1400 Centauri is an orange K-type star, and the adjoining number "5" ranks V1400 Centauri's relative temperature on a scale of 9 (coolest) to 0 (hottest) for K-type stars. V1400 Centauri is given the subgiant luminosity class "IV", because it has a brighter luminosity than K-type main-sequence stars (luminosity class V). [3]: 5 [c] The letter "e" indicates V1400 Centauri exhibits weak hydrogen-alpha emission lines in its visible light spectrum. [3]: 5 Lastly, "Li" indicates V1400 Centauri is abundant in lithium. [3]: 5
Measurements from the Gaia spacecraft's third and most recent data release (Gaia DR3) indicate V1400 Centauri is about 7% larger than the Sun in radius (1.07 R☉; 740,000 km; 460,000 mi), [7] but is slightly less massive than the Sun. [5] [6]: 2 Depending on whether magnetic effects are taken into account in V1400 Centauri's stellar evolution or not, the star's mass could be either 0.98 M☉ or 0.89 M☉, respectively. [5]: 4 Young stars tend to be magnetically active, [14] and neglecting their magnetic effects results in an underestimation of their mass. [5]: 4, 9 An older estimate of V1400 Centauri's mass from Gaia's second data release (Gaia DR2) in 2018 gives 0.95 M☉, but does not take magnetic effects into account. [6]: 2
V1400 Centauri is cooler and less luminous than the Sun, with an effective temperature of about 4,300 K (4,030 °C; 7,280 °F) and a luminosity about 34% that of the Sun. [7] V1400 Centauri has an estimated surface gravity of about 200 m/s2 (over 20 times the gravity of Earth), based on Gaia measurements of the star's brightness, distance, and color. [1] [d] Gaia measurements also indicate V1400 Centauri has a lower metallicity than the Sun. [1] [e] Viewed from Earth, V1400 Centauri appears marginally redder than a typical K5-type star due to light extinction by interstellar dust between Earth and the star. [f] The star does not exhibit excess thermal emission in near- and mid- infrared wavelengths and lacks strong emission lines in its spectrum, which indicates it lacks a substantial accretion disk. [3]: 10
Rotation and variability
Like most young stars, V1400 Centauri rotates rapidly with a rotation period of approximately 3.2 days. [3]: 8 The rapid rotation of V1400 Centauri strengthens its magnetic field via the dynamo process, which leads to the formation of starspots on its surface. [8]: 6 As V1400 Centauri rotates, its starspots come into and out of view, causing the star's brightness to periodically fluctuate by 5%, or about 0.1 magnitudes in amplitude. [8]: 2 The star's rotation period varies by 0.02 days over a 5.4-year-long magnetic activity cycle, due to the long-term movement of starspots across the star's differentially rotating surface. [8]: 6 [15]: 2847 V1400 Centauri is known to emit soft X-rays [3]: 8 due to its corona being heated by its rotationally-strengthened magnetic field. [16]
Spectroscopic measurements of Doppler broadening in V1400 Centauri's spectral absorption lines indicate the star has a projected rotational velocity of 14.6±0.4 km/s. [9]: 415–416 Given V1400 Centauri's rotation period, radius, and temperature, the star's true equatorial rotation velocity is 15.7±1.7 km/s, [9]: 418 which indicates that the star's rotation axis is inclined 68°±10° with respect to Earth's line of sight. [9]: 419
Because of its young age, starspot variability, and lack of dust accretion, V1400 Centauri is classified as a weak-lined T Tauri variable. [9]: 412 [2] The star underwent a series of deep eclipse-like dimmings in 2007, which have been ascribed to the coincidental transit of J1407b's circumstellar disk. [10] The star shows no signs of periodic dimming caused by transiting planets larger than Jupiter. [8]
2007 eclipse by J1407b
During April–May 2007, telescopes of the Super Wide Angle Search for Planets (SuperWASP) and All Sky Automated Survey (ASAS) projects recorded V1400 Centauri undergoing a series of significant dimming events, each lasting several days. [8] The pattern of these dimming events was complex yet nearly symmetrical, indicating they were caused by a disk-like structure eclipsing V1400 Centauri. The light curve of V1400 Centauri during 2007 shows at least five major dimming events, including a very long and deep central eclipse bracketed by two pairs of shorter eclipses symmetrically occurring 12 days and 26 days before and after the deep eclipse midpoint. [3] The deep eclipse lasted about 14 days (7 days from midpoint) and caused V1400 Centauri to dim by at least 3.3 magnitudes, or fall below 4.8% of its original brightness. [3] The short eclipses before and after the deep eclipse were shallower and caused the star to dim by at least 1 magnitude, or fall below 40% of the star's original brightness. [3] [15]
A team of astronomers led by Eric E. Mamajek discovered the 2007 eclipse of V1400 Centauri while they were investigating SuperWASP's photometric data. Mamajek's team originally intended to use the SuperWASP data to validate candidate low-mass stars of the Scorpius–Centaurus association, which they had been studying since 2009. [3] Mamajek's team presented their discovery of V1400 Centauri's eclipse in January 2012 at the 219th American Astronomical Society conference in Austin, Texas, and then formally published their results in The Astronomical Journal in March 2012. [18] [3]
Because V1400 Centauri does not emit excess infrared thermal radiation, the object that eclipsed the star must be substellar in mass, which means it could either be a brown dwarf or a planet. Mamajek's team hypothesized that this substellar object could either be orbiting V1400 Centauri as a planet or binary companion, or is a gravitationally unbound object that coincidentally passed in front of the star. The substellar object was first dubbed "J1407b" in a paper published by Tim van Werkhoven, Matthew Kenworthy, and Eric Mamajek in 2014, which assumed the object was orbiting V1400 Centauri. [15]
Bound companion hypothesis
Mamajek's team initially considered the bound companion hypothesis plausible because there are known eclipsing binary stars where one component has a circumstellar disk (for example, Epsilon Aurigae), and V1400 Centauri is young enough that a protoplanetary disk could exist around the star and its putative companion. [3]
J1407b has been popularly called a "Super Saturn" [19] or a "Saturn on steroids" [20] [21] due to its massive system of circumplanetary rings with a radius of approximately 90 million km (0.6 AU). [22] The orbital period of J1407b is estimated to be around a decade (3.5 to 13.8 years or 3825 days), and its most probable mass is approximately 13 to 26 Jupiter masses which would make the companion a brown dwarf but with considerable uncertainty. [22] The ringed body can be ruled out as being a star with mass of over 80 Jupiter masses at greater than 99% confidence. [22] The ring system has an estimated mass similar to that of the Earth. [23] A major gap in the rings at about 61 million km (0.4 AU) from its center is considered to be indirect evidence of the existence of a shepherd exomoon with mass up to 0.8 Earth masses, [22] but the exomoon hypothesis was challenged by a 2019 study. [24]
J1407b has not been observed since its transit in 2007, which could be interpreted as the object being in a highly eccentric orbit around the star. [25] Such an orbit could disrupt the ring system of J1407b. [20] Dynamical simulations run by astronomers Steven Rieder and Matthew Kenworthy indicate that in order for J1407b's ring system to be stable, the rings must orbit J1407b in a retrograde motion, opposite to the direction J1407b orbits its host star. [25] [20] This retrograde solution for the ring system of J1407b allows for longer ring lifetimes as well as further constraints to the age of the ring system. [25] The rings may be replenished over timescales as a result of processes that produce additional debris around J1407b, such as the tidal disruption of comets. [25]
| Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b (unconfirmed) | 20.0±6.0 MJ | 3.9±1.7 | 3725±900 | >0.6 | — | — |
No additional transits from Jupiter-sized or larger planets were discovered in a 21-year long observational series by 2023. [8]
Unbound object hypothesis
Issues with the stability of any rings combined with the lack of detection of another eclipse, suggests that J1407b may not be bound to J1407. [6] No other deep eclipses has been found in the data spanning from 1890 to 1990, nor in recent time-series photometry from 2012-2018. A significant proportion of orbital periods for J1407b from 5 to 20 years can be disregarded, therefore if there is an actual orbital period it is likely outside of this range. [6]
High-resolution imaging of V1400 Centauri by the Atacama Large Millimeter Array (ALMA) in 2017 found no evidence of a bound companion >4 MJ in mass, but did detect a point source consistent with an unbound, <6 MJ substellar object surrounded by a disk of warm dust. This may be the object which transited V1400 Centauri in 2007, or it may be a background galaxy or an image artifact, which is considered less likely. [10]
See also
Notes
- ^ 3.206±0.002 d is the median rotation period of V1400 Centauri throughout its 5.4-year magnetic activity cycle. [8]: 6
- ^ Proper motion is split into right ascension (RA) and declination (Dec) components. By convention, positive RA is eastward and positive Dec is northward in the equatorial coordinate system. The measured proper motion components of V1400 Centauri are −23.108±0.015 mas/yr and −21.048±0.017 mas/yr in RA and Dec, respectively. [1] Since both RA and Dec components of V1400 Centauri's proper motion are negative, its proper motion is pointed towards the west and south directions, hence southwest.
- ^ The term " subgiant" and its associated luminosity class "IV" can either refer to the life stage between the main-sequence and giant phases near the end of a star's life, or it can strictly refer to a star's luminosity only. In the case of V1400 Centauri, the latter definition is used since it is appropriate for the star's young age.
- ^ The Gaia DR3 table gives log g = 4.302 as the base 10 logarithm of surface gravity in cgs units. [1] Raising 10 to the power of log g gives the star's surface gravity g in cgs units of cm/s2. Converting the result to the SI acceleration units of m/s2 gives g ≈ 200.4 m/s2 for V1400 Centauri's surface gravity.
- ^ The Gaia DR3 table gives the [Fe/H] metallicity (iron abundance relative to the Sun) as a base 10 logarithmic quantity. V1400 Centauri has a negative [Fe/H] metallicity of –0.1903, which indicates a lower iron abundance than the Sun. [1]
-
^ The latest estimate for V1400 Centauri's
extinction reddening index is E(GBP–GRP) = 0.0414+0.0518
−0.0314 mag, from Gaia DR3 (2022). [7] Mamajek et al. (2012) claimed V1400 Centauri is consistent with being slightly reddened, [3]: 5 whereas van Werkhoven et al. (2014) claimed it is statistically consistent with being unreddened. [15]: 2848
References
- ^ a b c d e f g h i j Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211. Bibcode: 2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c "V1400 Cen". International Variable Star Index. AAVSO. Archived from the original on 1 August 2023. Retrieved 1 August 2023.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x Mamajek, Eric E.; Quillen, Alice C.; Pecaut, Mark J.; Moolekamp, Fred; Scott, Erin L.; Kenworthy, Matthew A.; Collier Cameron, Andrew; Parley, Neil R. (March 2012). "Planetary Construction Zones in Occultation: Discovery of an Extrasolar Ring System Transiting a Young Sun-like Star and Future Prospects for Detecting Eclipses by Circumsecondary and Circumplanetary Disks". The Astronomical Journal. 143 (3): 72. arXiv: 1108.4070. Bibcode: 2012AJ....143...72M. doi: 10.1088/0004-6256/143/3/72. S2CID 55818711.
- ^ a b c d e f "V* V1400 Cen". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 23 May 2024.
- ^ a b c d e Fernandes, Rachel B.; Hardegree-Ullman, Kevin K.; Pascucci, Ilaria; Bergsten, Galen J.; Mulders, Gijs D.; Cunha, Katia; et al. (October 2023). "Using Photometrically Derived Properties of Young Stars to Refine TESS's Transiting Young Planet Survey Completeness". The Astronomical Journal. 166 (4): 12. arXiv: 2308.13039. Bibcode: 2023AJ....166..175F. doi: 10.3847/1538-3881/acf4f0. 175. Gaia DR3 data table and mass estimates for V1400 Centauri at VizieR.
- ^ a b c d e f g h i Mentel, R. T.; Kenworthy, M. A.; Cameron, D. A.; Scott, E. L.; Mellon, S. N.; Hudec, R.; Birkby, J. L.; Mamajek, E. E.; Schrimpf, A.; Reichart, D. E.; Haislip, J. B.; Kouprianov, V. V.; Hambsch, F.-J.; Tan, T.-G.; Hills, K. (November 2018). "Constraining the period of the ringed secondary companion to the young star J1407 with photographic plates". Astronomy & Astrophysics. 619: A157. arXiv: 1810.05171. Bibcode: 2018A&A...619A.157M. doi: 10.1051/0004-6361/201834004. ISSN 0004-6361. S2CID 55015149.
- ^ a b c d e f g h Gaia Collaboration (May 2022). "VizieR Online Data Catalog: Gaia DR3 Part 1. Main source". VizieR. I/355. Centre de données astronomiques de Strasbourg. Bibcode: 2022yCat.1355....0G. doi: 10.26093/cds/vizier.1355.
- ^ a b c d e f g h i Barmentloo, S.; Dik, C.; Kenworthy, M. A.; Mamajek, E. E.; Hambsch, F.-J.; Reichart, D. E.; Rodriguez, J. E.; Van Dam, D. M. (2021). "A search for transiting companions in the J1407 (V1400 Cen) system". Astronomy & Astrophysics. 652: A117. arXiv: 2106.15902. Bibcode: 2021A&A...652A.117B. doi: 10.1051/0004-6361/202140768. S2CID 235683556.
- ^ a b c d e Kenworthy, M. A.; Lacour, S.; et al. (January 2015). "Mass and period limits on the ringed companion transiting the young star J1407". Monthly Notices of the Royal Astronomical Society. 446 (1): 411–427. arXiv: 1410.6577. Bibcode: 2015MNRAS.446..411K. doi: 10.1093/mnras/stu2067.
- ^ a b c d Kenworthy, M. A.; Klaassen, P. D.; et al. (January 2020). "ALMA and NACO observations towards the young exoring transit system J1407 (V1400 Cen)". Astronomy & Astrophysics. 633: A115. arXiv: 1912.03314. Bibcode: 2020A&A...633A.115K. doi: 10.1051/0004-6361/201936141.
- ^ Lasker, B. M.; Russell, J. L.; Jenker, H.; Sturch, C. R.; McLean, B. J.; Shara, M. M. (February 1996). "VizieR Online Data Catalog: The HST Guide Star Catalog, Version 1.1". VizieR. I/220. Centre de données astronomiques de Strasbourg. Bibcode: 1996yCat.1220....0L.
- ^ Kazarovets, E. V; Samus, N. N; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N (October 2015). "The 81st Name-List of Variable Stars. Part I - RA 00h to 17h30" (PDF). Information Bulletin on Variable Stars. 6151 (1): 22. Bibcode: 2015IBVS.6151....1K.
- ^ Preibisch, Thomas; Mamajek, Eric (December 2008). "The Nearest OB Association: Scorpius-Centaurus (Sco OB2)" (PDF). In Reipurth, Bo (ed.). Handbook of Star Forming Regions, Volume II: The Southern Sky. Vol. 5. ASP Monograph Publications. pp. 235–284. arXiv: 0809.0407. Bibcode: 2008hsf2.book..235P. ISBN 978-1-58381-671-4. Retrieved 14 July 2024.
- ^ Mathur, Savita; Claytor, Zachary R.; Santos, Ângela R. G.; García, Rafael A.; Amard, Louis; Bugnet, Lisa; et al. (June 2023). Evolution of rotation and magnetic activity of solar-like stars with age:magneto-(gyro-)chronology. PLATO Stellar Science Conference 2023. Milazzo, Italy. Bibcode: 2023plat.confE..36M. doi: 10.5281/zenodo.8140785. 404.04.
- ^ a b c d van Werkhoven, T. I. M.; Kenworthy, M. A.; Mamajek, E. E. (July 2014). "Analysis of 1SWASP J140747.93-394542.6 eclipse fine-structure: hints of exomoons". Monthly Notices of the Royal Astronomical Society. 441 (4): 2845–2854. Bibcode: 2014MNRAS.441.2845V. doi: 10.1093/mnras/stu725.
- ^ "Young Stars and Star Clusters". Chandra X-ray Observatory. NASA. 10 August 2012. Retrieved 14 July 2024.
- ^ "Search SuperWASP Time Series". NASA Exoplanet Archive. NASA. Archived from the original on 27 November 2022. Retrieved 27 November 2022.
- ^ Mamajek, Eric E.; Quillen, A. C.; Pecaut, M.; Moolekamp, F.; Scott, E. L.; Kenworthy, M. A.; et al. (January 2012). Planetary Construction Zones in Occultation: Eclipses by Circumsecondary and Circumplanetary Disks and a Candidate Eclipse of a Pre-Main Sequence Star in Sco-Cen. 219th AAS Meeting. Austin, Texas: American Astronomical Society. Bibcode: 2012AAS...21940404M. 404.04. Retrieved 12 July 2024.
- ^ Gigantic ring system around J1407b much larger, heavier than Saturn's Archived 2017-12-25 at the Wayback Machine, on University of Rochester website.
- ^ a b c St. Fleur, Nicholas (13 October 2016). "Distant Ringed Object Could Be 'Saturn on Steroids'". New York Times. Archived from the original on 20 May 2018. Retrieved 14 October 2016.
- ^ O'Neill, Ian (12 January 2012). "'Saturn on Steroids' Exoplanet Discovered?". Discovery News. Archived from the original on 11 March 2016. Retrieved 27 January 2014.
- ^ a b c d Kenworthy, Matthew A.; Mamajek, Eric E. (22 January 2015). "Modeling giant extrasolar ring systems in eclipse and the case of J1407b: sculpting by exomoons?". The Astrophysical Journal. 800 (2): 126. arXiv: 1501.05652. Bibcode: 2015ApJ...800..126K. doi: 10.1088/0004-637X/800/2/126. S2CID 56118870.
- ^ "Gigantic ring system around J1407b much larger, heavier than Saturn's". University of Rochester. 26 January 2015. Archived from the original on 21 August 2017. Retrieved 27 January 2015.
- ^ a b Sutton, P. J. (2019). "Mean motion resonances with nearby moons: an unlikely origin for the gaps observed in the ring around the exoplanet J1407b". Monthly Notices of the Royal Astronomical Society. 486 (2): 1681–1689. arXiv: 1902.09285. Bibcode: 2019MNRAS.486.1681S. doi: 10.1093/mnras/stz563. S2CID 119546405.
- ^ a b c d Rieder, Steven; Kenworthy, Matthew A. (21 November 2016). "Constraints on the size and dynamics of the J1407b ring system". Astronomy & Astrophysics. 596 (A9): A9. arXiv: 1609.08485. Bibcode: 2016A&A...596A...9R. doi: 10.1051/0004-6361/201629567. S2CID 118413749.
External links
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Centaurus |
| Right ascension | 14h 07m 47.92976s [1] |
| Declination | −39° 45′ 42.7671″ [1] |
| Apparent magnitude (V) | 12.2–15.6 [2] |
| Characteristics | |
| Evolutionary stage | Pre-main sequence [3] |
| Spectral type | K5 IVe Li [3] [4] |
| Variable type | rotational T Tau and eclipsing [2] |
| Astrometry | |
| Radial velocity (Rv) | 5.904±0.151 [4] km/s |
| Proper motion (μ) |
RA: −23.108±0.015
mas/
yr
[1] Dec.: −21.048±0.017 mas/ yr [1] |
| Parallax (π) | 7.2351 ± 0.0140 mas [1] |
| Distance | 450.8 ± 0.9
ly (138.2 ± 0.3 pc) |
| Details | |
| Mass | Gaia DR3 with
magnetism:
[5] 0.977+0.023 −0.045 M☉ Gaia DR3 without magnetism: [5] 0.891+0.062 −0.144 M☉ Gaia DR2: [6]: 2 0.95±0.10 M☉ |
| Radius | 1.0661+0.0062 −0.0139 [7] R☉ |
| Luminosity | 0.3431+0.0067 −0.0064 [7] L☉ |
| Surface gravity (log g) | 4.302+0.0243 −0.0243 [7] cgs |
| Temperature | 4343+24 −29 [7] K |
| Metallicity [Fe/H] | −0.1903+0.0448 −0.0422 [7] dex |
| Rotation | 3.206±0.002 d [8]: 6 [a] |
| Rotational velocity (v sin i) | 14.6±0.4 [9] km/s |
| Age | ~16
[3] or 21.38+4.30 −7.60 [6]: 2 Myr |
| Other designations | |
| Database references | |
| SIMBAD | data |
V1400 Centauri (known under its SuperWASP catalogue entry 1SWASP J140747.93−394542.6, or simply J1407) is a young, pre-main-sequence star that was eclipsed by a likely free-floating substellar object with a circumstellar disk or rings (known as J1407b or Mamajek's Object) in April–May 2007. With an age around 20 million years, the star is about as massive as the Sun and is located in the constellation Centaurus at a distance of 451 light-years away from the Sun. V1400 Centauri is a member of Upper Centaurus–Lupus subgroup of the Scorpius–Centaurus association, a group of young, comoving stars close to the Sun.
The discovery of J1407b's 2007 eclipse of V1400 Centauri was announced in 2012 by a team of astronomers led by Eric E. Mamajek, who directed an analysis of photometric data from the Super Wide Angle Search for Planets (SuperWASP) sky survey. Mamajek's team hypothesized that J1407b is a substellar object that could either be orbiting the star as a planet or binary companion, or is a gravitationally unbound object that coincidentally passed in front of the star. [3] Later studies have since found evidence disfavoring the bound companion hypothesis, which leaves the unbound hypothesis as the most likely explanation for J1407b's nature: no additional eclipses in V1400 Centauri have been observed after 2007 nor during 1890–1990, [6] [8] which leaves out very few possible orbits where the massive rings of J1407b can theoretically repeat eclipses of V1400 Centauri while being stable against the star's gravitational influence. [6]: 7
High-resolution imaging by the Atacama Large Millimeter Array (ALMA) in 2017 revealed a single faint object near V1400 Centauri, which could either be a young substellar object surrounded by a circumstellar disk, or a background galaxy. This faint object is far enough away from V1400 Centauri that it cannot be gravitationally bound to the star, which makes it a very likely candidate for J1407b. However, the faint object has only been observed once, so it is not yet confirmed whether it is a moving foreground object or a stationary background galaxy. If this faint object is a substellar object, then it would have a mass below 6 Jupiter masses, which would also make it a sub-brown dwarf or a rogue planet. [10]
Name and catalogue history
The star was first catalogued in the 1990s by the Hubble Guide Star Catalog, which found the star and measured its position in a pair of photographic plates taken in 1974 and 1979. [11] The star has been catalogued by other sky surveys, including the All Sky Automated Survey (ASAS), Two Micron All-Sky Survey (2MASS), Super Wide Angle Search for Planets (1SWASP), and the Wide-field Infrared Survey Explorer (WISE). [4] Typically in these catalogues, the star is given designations such as 1SWASP J140747.93–394542.6, which comprises the survey name followed by the star's location in equatorial coordinates. [4] As such designations can be unwieldy, researchers simply call the star "J1407". [3]: 5 [10] The star was given the official variable star designation V1400 Centauri in 2015, when it was added to the International Astronomical Union's General Catalogue of Variable Stars. [12]
Stellar properties
Location and age
V1400 Centauri is located in the constellation Centaurus, about 40 degrees south of the celestial equator. The most recent parallax measurements by the Gaia spacecraft indicate V1400 Centauri is located 450.8 ± 0.9 light-years (138.2 ± 0.3 parsecs) from the Sun. [1] Observations of V1400 Centauri's position over time have shown that it has a southwestward [b] proper motion consistent with that of the Scorpius–Centaurus association, an OB association of young stars with ages between 11–17 million years and distances between 380–470 ly (118–145 pc) from the Sun. [3]: 4 The Scorpius–Centaurus association is the nearest OB association to the Sun, and is believed to have formed out of a molecular cloud that has since been blown away by the stellar winds of the association's most massive stars. [13]: 236, 250
V1400 Centauri is closest to the Upper Centaurus–Lupus subgroup of the Scorpius–Centaurus association, which has an age range of 14–18 million years and distance range of 380–460 ly (115–141 pc).
[3]: 5-6 Given V1400 Centauri's similar distance and proper motion, it very likely belongs to the Scorpius–Centaurus association, which would mean it must be a young star within the age range of the Upper Centaurus–Lupus subgroup.
[3]: 5-6 A 2012 estimate of V1400 Centauri's age assumes it is equal to 16 million years,
[3]: 6 the mean age of the Upper Centaurus–Lupus subgroup, while a 2018 estimate from Gaia measurements puts the star's age at 21.38+4.30
−7.60 million years.
[6]: 2
Spectral type and physical characteristics
V1400 Centauri is a pre-main sequence star of spectral class K5 IVe Li. [4] [3]: 5 "K" means V1400 Centauri is an orange K-type star, and the adjoining number "5" ranks V1400 Centauri's relative temperature on a scale of 9 (coolest) to 0 (hottest) for K-type stars. V1400 Centauri is given the subgiant luminosity class "IV", because it has a brighter luminosity than K-type main-sequence stars (luminosity class V). [3]: 5 [c] The letter "e" indicates V1400 Centauri exhibits weak hydrogen-alpha emission lines in its visible light spectrum. [3]: 5 Lastly, "Li" indicates V1400 Centauri is abundant in lithium. [3]: 5
Measurements from the Gaia spacecraft's third and most recent data release (Gaia DR3) indicate V1400 Centauri is about 7% larger than the Sun in radius (1.07 R☉; 740,000 km; 460,000 mi), [7] but is slightly less massive than the Sun. [5] [6]: 2 Depending on whether magnetic effects are taken into account in V1400 Centauri's stellar evolution or not, the star's mass could be either 0.98 M☉ or 0.89 M☉, respectively. [5]: 4 Young stars tend to be magnetically active, [14] and neglecting their magnetic effects results in an underestimation of their mass. [5]: 4, 9 An older estimate of V1400 Centauri's mass from Gaia's second data release (Gaia DR2) in 2018 gives 0.95 M☉, but does not take magnetic effects into account. [6]: 2
V1400 Centauri is cooler and less luminous than the Sun, with an effective temperature of about 4,300 K (4,030 °C; 7,280 °F) and a luminosity about 34% that of the Sun. [7] V1400 Centauri has an estimated surface gravity of about 200 m/s2 (over 20 times the gravity of Earth), based on Gaia measurements of the star's brightness, distance, and color. [1] [d] Gaia measurements also indicate V1400 Centauri has a lower metallicity than the Sun. [1] [e] Viewed from Earth, V1400 Centauri appears marginally redder than a typical K5-type star due to light extinction by interstellar dust between Earth and the star. [f] The star does not exhibit excess thermal emission in near- and mid- infrared wavelengths and lacks strong emission lines in its spectrum, which indicates it lacks a substantial accretion disk. [3]: 10
Rotation and variability
Like most young stars, V1400 Centauri rotates rapidly with a rotation period of approximately 3.2 days. [3]: 8 The rapid rotation of V1400 Centauri strengthens its magnetic field via the dynamo process, which leads to the formation of starspots on its surface. [8]: 6 As V1400 Centauri rotates, its starspots come into and out of view, causing the star's brightness to periodically fluctuate by 5%, or about 0.1 magnitudes in amplitude. [8]: 2 The star's rotation period varies by 0.02 days over a 5.4-year-long magnetic activity cycle, due to the long-term movement of starspots across the star's differentially rotating surface. [8]: 6 [15]: 2847 V1400 Centauri is known to emit soft X-rays [3]: 8 due to its corona being heated by its rotationally-strengthened magnetic field. [16]
Spectroscopic measurements of Doppler broadening in V1400 Centauri's spectral absorption lines indicate the star has a projected rotational velocity of 14.6±0.4 km/s. [9]: 415–416 Given V1400 Centauri's rotation period, radius, and temperature, the star's true equatorial rotation velocity is 15.7±1.7 km/s, [9]: 418 which indicates that the star's rotation axis is inclined 68°±10° with respect to Earth's line of sight. [9]: 419
Because of its young age, starspot variability, and lack of dust accretion, V1400 Centauri is classified as a weak-lined T Tauri variable. [9]: 412 [2] The star underwent a series of deep eclipse-like dimmings in 2007, which have been ascribed to the coincidental transit of J1407b's circumstellar disk. [10] The star shows no signs of periodic dimming caused by transiting planets larger than Jupiter. [8]
2007 eclipse by J1407b
During April–May 2007, telescopes of the Super Wide Angle Search for Planets (SuperWASP) and All Sky Automated Survey (ASAS) projects recorded V1400 Centauri undergoing a series of significant dimming events, each lasting several days. [8] The pattern of these dimming events was complex yet nearly symmetrical, indicating they were caused by a disk-like structure eclipsing V1400 Centauri. The light curve of V1400 Centauri during 2007 shows at least five major dimming events, including a very long and deep central eclipse bracketed by two pairs of shorter eclipses symmetrically occurring 12 days and 26 days before and after the deep eclipse midpoint. [3] The deep eclipse lasted about 14 days (7 days from midpoint) and caused V1400 Centauri to dim by at least 3.3 magnitudes, or fall below 4.8% of its original brightness. [3] The short eclipses before and after the deep eclipse were shallower and caused the star to dim by at least 1 magnitude, or fall below 40% of the star's original brightness. [3] [15]
A team of astronomers led by Eric E. Mamajek discovered the 2007 eclipse of V1400 Centauri while they were investigating SuperWASP's photometric data. Mamajek's team originally intended to use the SuperWASP data to validate candidate low-mass stars of the Scorpius–Centaurus association, which they had been studying since 2009. [3] Mamajek's team presented their discovery of V1400 Centauri's eclipse in January 2012 at the 219th American Astronomical Society conference in Austin, Texas, and then formally published their results in The Astronomical Journal in March 2012. [18] [3]
Because V1400 Centauri does not emit excess infrared thermal radiation, the object that eclipsed the star must be substellar in mass, which means it could either be a brown dwarf or a planet. Mamajek's team hypothesized that this substellar object could either be orbiting V1400 Centauri as a planet or binary companion, or is a gravitationally unbound object that coincidentally passed in front of the star. The substellar object was first dubbed "J1407b" in a paper published by Tim van Werkhoven, Matthew Kenworthy, and Eric Mamajek in 2014, which assumed the object was orbiting V1400 Centauri. [15]
Bound companion hypothesis
Mamajek's team initially considered the bound companion hypothesis plausible because there are known eclipsing binary stars where one component has a circumstellar disk (for example, Epsilon Aurigae), and V1400 Centauri is young enough that a protoplanetary disk could exist around the star and its putative companion. [3]
J1407b has been popularly called a "Super Saturn" [19] or a "Saturn on steroids" [20] [21] due to its massive system of circumplanetary rings with a radius of approximately 90 million km (0.6 AU). [22] The orbital period of J1407b is estimated to be around a decade (3.5 to 13.8 years or 3825 days), and its most probable mass is approximately 13 to 26 Jupiter masses which would make the companion a brown dwarf but with considerable uncertainty. [22] The ringed body can be ruled out as being a star with mass of over 80 Jupiter masses at greater than 99% confidence. [22] The ring system has an estimated mass similar to that of the Earth. [23] A major gap in the rings at about 61 million km (0.4 AU) from its center is considered to be indirect evidence of the existence of a shepherd exomoon with mass up to 0.8 Earth masses, [22] but the exomoon hypothesis was challenged by a 2019 study. [24]
J1407b has not been observed since its transit in 2007, which could be interpreted as the object being in a highly eccentric orbit around the star. [25] Such an orbit could disrupt the ring system of J1407b. [20] Dynamical simulations run by astronomers Steven Rieder and Matthew Kenworthy indicate that in order for J1407b's ring system to be stable, the rings must orbit J1407b in a retrograde motion, opposite to the direction J1407b orbits its host star. [25] [20] This retrograde solution for the ring system of J1407b allows for longer ring lifetimes as well as further constraints to the age of the ring system. [25] The rings may be replenished over timescales as a result of processes that produce additional debris around J1407b, such as the tidal disruption of comets. [25]
| Companion (in order from star) |
Mass |
Semimajor axis ( AU) |
Orbital period ( days) |
Eccentricity | Inclination | Radius |
|---|---|---|---|---|---|---|
| b (unconfirmed) | 20.0±6.0 MJ | 3.9±1.7 | 3725±900 | >0.6 | — | — |
No additional transits from Jupiter-sized or larger planets were discovered in a 21-year long observational series by 2023. [8]
Unbound object hypothesis
Issues with the stability of any rings combined with the lack of detection of another eclipse, suggests that J1407b may not be bound to J1407. [6] No other deep eclipses has been found in the data spanning from 1890 to 1990, nor in recent time-series photometry from 2012-2018. A significant proportion of orbital periods for J1407b from 5 to 20 years can be disregarded, therefore if there is an actual orbital period it is likely outside of this range. [6]
High-resolution imaging of V1400 Centauri by the Atacama Large Millimeter Array (ALMA) in 2017 found no evidence of a bound companion >4 MJ in mass, but did detect a point source consistent with an unbound, <6 MJ substellar object surrounded by a disk of warm dust. This may be the object which transited V1400 Centauri in 2007, or it may be a background galaxy or an image artifact, which is considered less likely. [10]
See also
Notes
- ^ 3.206±0.002 d is the median rotation period of V1400 Centauri throughout its 5.4-year magnetic activity cycle. [8]: 6
- ^ Proper motion is split into right ascension (RA) and declination (Dec) components. By convention, positive RA is eastward and positive Dec is northward in the equatorial coordinate system. The measured proper motion components of V1400 Centauri are −23.108±0.015 mas/yr and −21.048±0.017 mas/yr in RA and Dec, respectively. [1] Since both RA and Dec components of V1400 Centauri's proper motion are negative, its proper motion is pointed towards the west and south directions, hence southwest.
- ^ The term " subgiant" and its associated luminosity class "IV" can either refer to the life stage between the main-sequence and giant phases near the end of a star's life, or it can strictly refer to a star's luminosity only. In the case of V1400 Centauri, the latter definition is used since it is appropriate for the star's young age.
- ^ The Gaia DR3 table gives log g = 4.302 as the base 10 logarithm of surface gravity in cgs units. [1] Raising 10 to the power of log g gives the star's surface gravity g in cgs units of cm/s2. Converting the result to the SI acceleration units of m/s2 gives g ≈ 200.4 m/s2 for V1400 Centauri's surface gravity.
- ^ The Gaia DR3 table gives the [Fe/H] metallicity (iron abundance relative to the Sun) as a base 10 logarithmic quantity. V1400 Centauri has a negative [Fe/H] metallicity of –0.1903, which indicates a lower iron abundance than the Sun. [1]
-
^ The latest estimate for V1400 Centauri's
extinction reddening index is E(GBP–GRP) = 0.0414+0.0518
−0.0314 mag, from Gaia DR3 (2022). [7] Mamajek et al. (2012) claimed V1400 Centauri is consistent with being slightly reddened, [3]: 5 whereas van Werkhoven et al. (2014) claimed it is statistically consistent with being unreddened. [15]: 2848
References
- ^ a b c d e f g h i j Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv: 2208.00211. Bibcode: 2023A&A...674A...1G. doi: 10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
- ^ a b c "V1400 Cen". International Variable Star Index. AAVSO. Archived from the original on 1 August 2023. Retrieved 1 August 2023.
- ^ a b c d e f g h i j k l m n o p q r s t u v w x Mamajek, Eric E.; Quillen, Alice C.; Pecaut, Mark J.; Moolekamp, Fred; Scott, Erin L.; Kenworthy, Matthew A.; Collier Cameron, Andrew; Parley, Neil R. (March 2012). "Planetary Construction Zones in Occultation: Discovery of an Extrasolar Ring System Transiting a Young Sun-like Star and Future Prospects for Detecting Eclipses by Circumsecondary and Circumplanetary Disks". The Astronomical Journal. 143 (3): 72. arXiv: 1108.4070. Bibcode: 2012AJ....143...72M. doi: 10.1088/0004-6256/143/3/72. S2CID 55818711.
- ^ a b c d e f "V* V1400 Cen". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 23 May 2024.
- ^ a b c d e Fernandes, Rachel B.; Hardegree-Ullman, Kevin K.; Pascucci, Ilaria; Bergsten, Galen J.; Mulders, Gijs D.; Cunha, Katia; et al. (October 2023). "Using Photometrically Derived Properties of Young Stars to Refine TESS's Transiting Young Planet Survey Completeness". The Astronomical Journal. 166 (4): 12. arXiv: 2308.13039. Bibcode: 2023AJ....166..175F. doi: 10.3847/1538-3881/acf4f0. 175. Gaia DR3 data table and mass estimates for V1400 Centauri at VizieR.
- ^ a b c d e f g h i Mentel, R. T.; Kenworthy, M. A.; Cameron, D. A.; Scott, E. L.; Mellon, S. N.; Hudec, R.; Birkby, J. L.; Mamajek, E. E.; Schrimpf, A.; Reichart, D. E.; Haislip, J. B.; Kouprianov, V. V.; Hambsch, F.-J.; Tan, T.-G.; Hills, K. (November 2018). "Constraining the period of the ringed secondary companion to the young star J1407 with photographic plates". Astronomy & Astrophysics. 619: A157. arXiv: 1810.05171. Bibcode: 2018A&A...619A.157M. doi: 10.1051/0004-6361/201834004. ISSN 0004-6361. S2CID 55015149.
- ^ a b c d e f g h Gaia Collaboration (May 2022). "VizieR Online Data Catalog: Gaia DR3 Part 1. Main source". VizieR. I/355. Centre de données astronomiques de Strasbourg. Bibcode: 2022yCat.1355....0G. doi: 10.26093/cds/vizier.1355.
- ^ a b c d e f g h i Barmentloo, S.; Dik, C.; Kenworthy, M. A.; Mamajek, E. E.; Hambsch, F.-J.; Reichart, D. E.; Rodriguez, J. E.; Van Dam, D. M. (2021). "A search for transiting companions in the J1407 (V1400 Cen) system". Astronomy & Astrophysics. 652: A117. arXiv: 2106.15902. Bibcode: 2021A&A...652A.117B. doi: 10.1051/0004-6361/202140768. S2CID 235683556.
- ^ a b c d e Kenworthy, M. A.; Lacour, S.; et al. (January 2015). "Mass and period limits on the ringed companion transiting the young star J1407". Monthly Notices of the Royal Astronomical Society. 446 (1): 411–427. arXiv: 1410.6577. Bibcode: 2015MNRAS.446..411K. doi: 10.1093/mnras/stu2067.
- ^ a b c d Kenworthy, M. A.; Klaassen, P. D.; et al. (January 2020). "ALMA and NACO observations towards the young exoring transit system J1407 (V1400 Cen)". Astronomy & Astrophysics. 633: A115. arXiv: 1912.03314. Bibcode: 2020A&A...633A.115K. doi: 10.1051/0004-6361/201936141.
- ^ Lasker, B. M.; Russell, J. L.; Jenker, H.; Sturch, C. R.; McLean, B. J.; Shara, M. M. (February 1996). "VizieR Online Data Catalog: The HST Guide Star Catalog, Version 1.1". VizieR. I/220. Centre de données astronomiques de Strasbourg. Bibcode: 1996yCat.1220....0L.
- ^ Kazarovets, E. V; Samus, N. N; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N (October 2015). "The 81st Name-List of Variable Stars. Part I - RA 00h to 17h30" (PDF). Information Bulletin on Variable Stars. 6151 (1): 22. Bibcode: 2015IBVS.6151....1K.
- ^ Preibisch, Thomas; Mamajek, Eric (December 2008). "The Nearest OB Association: Scorpius-Centaurus (Sco OB2)" (PDF). In Reipurth, Bo (ed.). Handbook of Star Forming Regions, Volume II: The Southern Sky. Vol. 5. ASP Monograph Publications. pp. 235–284. arXiv: 0809.0407. Bibcode: 2008hsf2.book..235P. ISBN 978-1-58381-671-4. Retrieved 14 July 2024.
- ^ Mathur, Savita; Claytor, Zachary R.; Santos, Ângela R. G.; García, Rafael A.; Amard, Louis; Bugnet, Lisa; et al. (June 2023). Evolution of rotation and magnetic activity of solar-like stars with age:magneto-(gyro-)chronology. PLATO Stellar Science Conference 2023. Milazzo, Italy. Bibcode: 2023plat.confE..36M. doi: 10.5281/zenodo.8140785. 404.04.
- ^ a b c d van Werkhoven, T. I. M.; Kenworthy, M. A.; Mamajek, E. E. (July 2014). "Analysis of 1SWASP J140747.93-394542.6 eclipse fine-structure: hints of exomoons". Monthly Notices of the Royal Astronomical Society. 441 (4): 2845–2854. Bibcode: 2014MNRAS.441.2845V. doi: 10.1093/mnras/stu725.
- ^ "Young Stars and Star Clusters". Chandra X-ray Observatory. NASA. 10 August 2012. Retrieved 14 July 2024.
- ^ "Search SuperWASP Time Series". NASA Exoplanet Archive. NASA. Archived from the original on 27 November 2022. Retrieved 27 November 2022.
- ^ Mamajek, Eric E.; Quillen, A. C.; Pecaut, M.; Moolekamp, F.; Scott, E. L.; Kenworthy, M. A.; et al. (January 2012). Planetary Construction Zones in Occultation: Eclipses by Circumsecondary and Circumplanetary Disks and a Candidate Eclipse of a Pre-Main Sequence Star in Sco-Cen. 219th AAS Meeting. Austin, Texas: American Astronomical Society. Bibcode: 2012AAS...21940404M. 404.04. Retrieved 12 July 2024.
- ^ Gigantic ring system around J1407b much larger, heavier than Saturn's Archived 2017-12-25 at the Wayback Machine, on University of Rochester website.
- ^ a b c St. Fleur, Nicholas (13 October 2016). "Distant Ringed Object Could Be 'Saturn on Steroids'". New York Times. Archived from the original on 20 May 2018. Retrieved 14 October 2016.
- ^ O'Neill, Ian (12 January 2012). "'Saturn on Steroids' Exoplanet Discovered?". Discovery News. Archived from the original on 11 March 2016. Retrieved 27 January 2014.
- ^ a b c d Kenworthy, Matthew A.; Mamajek, Eric E. (22 January 2015). "Modeling giant extrasolar ring systems in eclipse and the case of J1407b: sculpting by exomoons?". The Astrophysical Journal. 800 (2): 126. arXiv: 1501.05652. Bibcode: 2015ApJ...800..126K. doi: 10.1088/0004-637X/800/2/126. S2CID 56118870.
- ^ "Gigantic ring system around J1407b much larger, heavier than Saturn's". University of Rochester. 26 January 2015. Archived from the original on 21 August 2017. Retrieved 27 January 2015.
- ^ a b Sutton, P. J. (2019). "Mean motion resonances with nearby moons: an unlikely origin for the gaps observed in the ring around the exoplanet J1407b". Monthly Notices of the Royal Astronomical Society. 486 (2): 1681–1689. arXiv: 1902.09285. Bibcode: 2019MNRAS.486.1681S. doi: 10.1093/mnras/stz563. S2CID 119546405.
- ^ a b c d Rieder, Steven; Kenworthy, Matthew A. (21 November 2016). "Constraints on the size and dynamics of the J1407b ring system". Astronomy & Astrophysics. 596 (A9): A9. arXiv: 1609.08485. Bibcode: 2016A&A...596A...9R. doi: 10.1051/0004-6361/201629567. S2CID 118413749.