RECORD
Searching for Extragalactic Exoplanetary Systems: the Curious Case of BD+20 2457
Earth and Planetary Astrophysics · Submitted 16 Apr 2021
abstract compiled · 2026-09-23 · no language-model review
The authors' main claim Given its orbital parameters and chemical properties, we suggest that BD+20 2457 is likely formed in the protodisk of the Galaxy, but we do not exclude the possibility of the star belonging to the debris of GE.
The compiled record
The paper's own sentences, arranged. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
Open the compiled record
The abstract, sentence by sentence
Planets and their host stars carry a long-term memory of their origin in their chemical compositions. Thus, identifying planets formed in different environments improves our understating of planetary formation. Although restricted to detecting exoplanets within the solar vicinity, we might be able to detect planetary systems that formed in small external galaxies and later merged with the Milky Way. In fact, Gaia data have unequivocally shown that the Galaxy underwent several significant minor mergers during its first billion years of formation. The stellar debris of one of these mergers, Gaia-Enceladus (GE), is thought to have built up most of the stellar halo in the solar neighborhood. In this Letter, we investigate the origin of known planet-host stars combining data from the NASA Exoplanet Archive with Gaia EDR3 and large-scale spectroscopic surveys. We adopt a kinematic criterion and identify 42 stars associated with the Milky Way's thick disk and one halo star. The only halo star identified, BD+20 2457, known to harbor two exoplanets, moves on a retrograde and highly eccentric orbit. Its chemical abundance pattern situates the star at the border between the thick disk, the old halo, and accreted populations. Given its orbital parameters and chemical properties, we suggest that BD+20 2457 is likely formed in the protodisk of the Galaxy, but we do not exclude the possibility of the star belonging to the debris of GE. Finally, we estimate a minimum age and mass limit for the star, which has implications for its planetary system and will be tested with future Transiting Exoplanet Survey Satellite observations.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | Planets and their host stars carry a long-term memory of their origin in their chemical compositions. | background 1.00 | 0.05 | 0.03 | asserted 1.00 |
| s1 | Thus, identifying planets formed in different environments improves our understating of planetary formation. | background 0.98 | 0.05 | 0.03 | asserted 0.97 |
| s2 | Although restricted to detecting exoplanets within the solar vicinity, we might be able to detect planetary systems that formed in small external galaxies and later merged with the Milky Way. | background 0.66 | 0.10 | 0.06 | speculative 0.76 |
| s3 | In fact, Gaia data have unequivocally shown that the Galaxy underwent several significant minor mergers during its first billion years of formation. | background 1.00 | 0.05 | 0.02 | asserted 1.00 |
| s4 | The stellar debris of one of these mergers, Gaia-Enceladus (GE), is thought to have built up most of the stellar halo in the solar neighborhood. | background 1.00 | 0.05 | 0.03 | hedged possibility 0.82 |
| s5 | In this Letter, we investigate the origin of known planet-host stars combining data from the NASA Exoplanet Archive with Gaia EDR3 and large-scale spectroscopic surveys. | contribution 0.90 | 0.89 | 0.04 | asserted 0.96 |
| s6 | We adopt a kinematic criterion and identify 42 stars associated with the Milky Way's thick disk and one halo star. | result 0.72 | 0.95 | 0.06 | asserted 1.00 |
| s7 | The only halo star identified, BD+20 2457, known to harbor two exoplanets, moves on a retrograde and highly eccentric orbit. | result 0.99 | 0.73 | 0.09 | asserted 1.00 |
| s8 | Its chemical abundance pattern situates the star at the border between the thick disk, the old halo, and accreted populations. | result 0.99 | 0.80 | 0.07 | asserted 0.98 |
| s9 | Given its orbital parameters and chemical properties, we suggest that BD+20 2457 is likely formed in the protodisk of the Galaxy, but we do not exclude the possibility of the star belonging to the debris of GE. | interpretation 1.00 | 0.85 | 0.78 | hedged possibility 1.00 |
| s10 | Finally, we estimate a minimum age and mass limit for the star, which has implications for its planetary system and will be tested with future Transiting Exoplanet Survey Satellite observations. | result 0.54 | 0.93 | 0.08 | asserted 0.85 |
What was examined, and what was not
- arXiv listing abstract v2
- full text
- figures and tables
- references and citing sentences
- relations to other papers
- P abstract
- S sections
- T body sentences
- C citations
- R cross-paper relations
The paper
Original abstract
Planets and their host stars carry a long-term memory of their origin in their chemical compositions. Thus, identifying planets formed in different environments improves our understating of planetary formation. Although restricted to detecting exoplanets within the solar vicinity, we might be able to detect planetary systems that formed in small external galaxies and later merged with the Milky Way. In fact, Gaia data have unequivocally shown that the Galaxy underwent several significant minor mergers during its first billion years of formation. The stellar debris of one of these mergers, Gaia-Enceladus (GE), is thought to have built up most of the stellar halo in the solar neighborhood. In this Letter, we investigate the origin of known planet-host stars combining data from the NASA Exoplanet Archive with Gaia EDR3 and large-scale spectroscopic surveys. We adopt a kinematic criterion and identify 42 stars associated with the Milky Way's thick disk and one halo star. The only halo star identified, BD+20 2457, known to harbor two exoplanets, moves on a retrograde and highly eccentric orbit. Its chemical abundance pattern situates the star at the border between the thick disk, the old halo, and accreted populations. Given its orbital parameters and chemical properties, we suggest that BD+20 2457 is likely formed in the protodisk of the Galaxy, but we do not exclude the possibility of the star belonging to the debris of GE. Finally, we estimate a minimum age and mass limit for the star, which has implications for its planetary system and will be tested with future Transiting Exoplanet Survey Satellite observations.
Human review
References
How the literature uses it
1 arXiv paper cite this in 1 sentence
What it cites · 4 sentences without a confident label
Uses data or values from 2 papers
-
We adopt the values from [ref] for the solar Galactocentric distance $R_⊙=8.22$, the local circular velocity $v_c = 243.0$, and the solar motion with respect to the local standard of rest $(U_⊙, V_⊙, W_⊙) = (11.10,7.20,7.25)$.
A purely acceleration-based measurement of the fundamental Galactic parameters · Data · 1.00
-
This Letter is based on a combination of data from the Exoplanet Archive with APOGEE DR16, GEDR3, GALAH DR3, and LAMOST DR5 ( [ref] see Appendix [ref] for details about the sample selection criteria).
The GALAH+ Survey: Third Data Release · Data · 0.97
Cites as background 1 paper
-
The accretion event of the massive dwarf galaxy GE ( [ref] ) occurred approximately $∼$10 Gyr ago ( [ref] ) and is thought to be responsible for the formation of the thick disk either by dynamical heating ( [ref] ) or by an induced star-formation burst ( [ref] ).
2006.01783 · Accreted or Heated? · 0.91
Discussion
Know something about this paper? Leave a comment, or highlight any passage above to comment on it.