JWST/NIRCam Transmission Spectroscopy of the Nearby Sub-Earth GJ 341b
We present a JWST/Near Infrared Camera (NIRCam) transmission spectrum from 3.9 to 5.0 μ m of the recently validated sub-Earth GJ 341b ( R _P = 0.92 R _⊕ , T _eq = 540 K) orbiting a nearby bright M1 star ( d = 10.4 pc, K _mag = 5.6). We use three independent pipelines to reduce the data from the thre...
| Main Authors: | , , , , , , , , , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2024-01-01
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| Series: | The Astronomical Journal |
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| Online Access: | https://doi.org/10.3847/1538-3881/ad19df |
| _version_ | 1827357796916527104 |
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| author | James Kirk Kevin B. Stevenson Guangwei Fu Jacob Lustig-Yaeger Sarah E. Moran Sarah Peacock Munazza K. Alam Natasha E. Batalha Katherine A. Bennett Junellie Gonzalez-Quiles Mercedes López-Morales Joshua D. Lothringer Ryan J. MacDonald E. M. May L. C. Mayorga Zafar Rustamkulov David K. Sing Kristin S. Sotzen Jeff A. Valenti Hannah R. Wakeford |
| author_facet | James Kirk Kevin B. Stevenson Guangwei Fu Jacob Lustig-Yaeger Sarah E. Moran Sarah Peacock Munazza K. Alam Natasha E. Batalha Katherine A. Bennett Junellie Gonzalez-Quiles Mercedes López-Morales Joshua D. Lothringer Ryan J. MacDonald E. M. May L. C. Mayorga Zafar Rustamkulov David K. Sing Kristin S. Sotzen Jeff A. Valenti Hannah R. Wakeford |
| author_sort | James Kirk |
| collection | DOAJ |
| description | We present a JWST/Near Infrared Camera (NIRCam) transmission spectrum from 3.9 to 5.0 μ m of the recently validated sub-Earth GJ 341b ( R _P = 0.92 R _⊕ , T _eq = 540 K) orbiting a nearby bright M1 star ( d = 10.4 pc, K _mag = 5.6). We use three independent pipelines to reduce the data from the three JWST visits and perform several tests to check for the significance of an atmosphere. Overall, our analysis does not uncover evidence of an atmosphere. Our null hypothesis tests find that none of our pipelines’ transmission spectra can rule out a flat line, although there is weak evidence for a Gaussian feature in two spectra from different pipelines (at 2.3 and 2.9 σ ). However, the candidate features are seen at different wavelengths (4.3 μ m versus 4.7 μ m), and our retrieval analysis finds that different gas species can explain these features in the two reductions (CO _2 at 3.1 σ compared to O _3 at 2.9 σ ), suggesting that they are not real astrophysical signals. Our forward-model analysis rules out a low-mean-molecular-weight atmosphere (<350× solar metallicity) to at least 3 σ , and disfavors CH _4 -dominated atmospheres at 1–3 σ , depending on the reduction. Instead, the forward models find our transmission spectra are consistent with no atmosphere, a hazy atmosphere, or an atmosphere containing a species that does not have prominent molecular bands across the NIRCam/F444W bandpass, such as a water-dominated atmosphere. Our results demonstrate the unequivocal need for two or more transit observations analyzed with multiple reduction pipelines, alongside rigorous statistical tests, to determine the robustness of molecular detections for small exoplanet atmospheres. |
| first_indexed | 2024-03-08T05:46:16Z |
| format | Article |
| id | doaj.art-fbffdda7f9df47f9b72b64ef7338d05b |
| institution | Directory Open Access Journal |
| issn | 1538-3881 |
| language | English |
| last_indexed | 2024-03-08T05:46:16Z |
| publishDate | 2024-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | The Astronomical Journal |
| spelling | doaj.art-fbffdda7f9df47f9b72b64ef7338d05b2024-02-05T09:48:03ZengIOP PublishingThe Astronomical Journal1538-38812024-01-0116739010.3847/1538-3881/ad19dfJWST/NIRCam Transmission Spectroscopy of the Nearby Sub-Earth GJ 341bJames Kirk0https://orcid.org/0000-0002-4207-6615Kevin B. Stevenson1https://orcid.org/0000-0002-7352-7941Guangwei Fu2https://orcid.org/0000-0002-3263-2251Jacob Lustig-Yaeger3https://orcid.org/0000-0002-0746-1980Sarah E. Moran4https://orcid.org/0000-0002-6721-3284Sarah Peacock5https://orcid.org/0000-0002-1046-025XMunazza K. Alam6https://orcid.org/0000-0003-4157-832XNatasha E. Batalha7https://orcid.org/0000-0003-1240-6844Katherine A. Bennett8https://orcid.org/0000-0002-9030-0132Junellie Gonzalez-Quiles9https://orcid.org/0000-0002-9032-8530Mercedes López-Morales10https://orcid.org/0000-0003-3204-8183Joshua D. Lothringer11https://orcid.org/0000-0003-3667-8633Ryan J. MacDonald12https://orcid.org/0000-0003-4816-3469E. M. May13https://orcid.org/0000-0002-2739-1465L. C. Mayorga14https://orcid.org/0000-0002-4321-4581Zafar Rustamkulov15https://orcid.org/0000-0003-4408-0463David K. Sing16https://orcid.org/0000-0001-6050-7645Kristin S. Sotzen17https://orcid.org/0000-0001-7393-2368Jeff A. Valenti18https://orcid.org/0000-0003-3305-6281Hannah R. Wakeford19https://orcid.org/0000-0003-4328-3867Department of Physics, Imperial College London , Prince Consort Road, London, SW7 2AZ, UKJohns Hopkins APL , Laurel, MD 20723, USA ; j.kirk22@imperial.ac.ukDepartment of Physics & Astronomy, Johns Hopkins University , Baltimore, MD 21218, USAJohns Hopkins APL , Laurel, MD 20723, USA ; j.kirk22@imperial.ac.ukDepartment of Planetary Sciences and Lunar and Planetary Laboratory, University of Arizona , Tuscon, AZ 85721-0092, USAUniversity of Maryland , Baltimore County, MD 21250, USA; NASA Goddard Space Flight Center , Greenbelt, MD 20771, USACarnegie Earth & Planets Laboratory , Washington, DC 20015, USA; Space Telescope Science Institute , Baltimore, MD 21218, USANASA Ames Research Center , Moffett Field, CA 94035-1000, USADepartment of Earth & Planetary Sciences, Johns Hopkins University , Baltimore, MD 21218, USADepartment of Earth & Planetary Sciences, Johns Hopkins University , Baltimore, MD 21218, USACenter for Astrophysics ∣ Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138, USADepartment of Physics, Utah Valley University , Orem, UT 84058 USADepartment of Astronomy, University of Michigan , 1085 S. University Avenue, Ann Arbor, MI 48109, USAJohns Hopkins APL , Laurel, MD 20723, USA ; j.kirk22@imperial.ac.ukJohns Hopkins APL , Laurel, MD 20723, USA ; j.kirk22@imperial.ac.ukDepartment of Earth & Planetary Sciences, Johns Hopkins University , Baltimore, MD 21218, USADepartment of Physics & Astronomy, Johns Hopkins University , Baltimore, MD 21218, USA; Department of Earth & Planetary Sciences, Johns Hopkins University , Baltimore, MD 21218, USAJohns Hopkins APL , Laurel, MD 20723, USA ; j.kirk22@imperial.ac.ukSpace Telescope Science Institute , Baltimore, MD 21218, USASchool of Physics, HH Wills Physics Laboratory, University of Bristol , Bristol, BS8 1TL, UKWe present a JWST/Near Infrared Camera (NIRCam) transmission spectrum from 3.9 to 5.0 μ m of the recently validated sub-Earth GJ 341b ( R _P = 0.92 R _⊕ , T _eq = 540 K) orbiting a nearby bright M1 star ( d = 10.4 pc, K _mag = 5.6). We use three independent pipelines to reduce the data from the three JWST visits and perform several tests to check for the significance of an atmosphere. Overall, our analysis does not uncover evidence of an atmosphere. Our null hypothesis tests find that none of our pipelines’ transmission spectra can rule out a flat line, although there is weak evidence for a Gaussian feature in two spectra from different pipelines (at 2.3 and 2.9 σ ). However, the candidate features are seen at different wavelengths (4.3 μ m versus 4.7 μ m), and our retrieval analysis finds that different gas species can explain these features in the two reductions (CO _2 at 3.1 σ compared to O _3 at 2.9 σ ), suggesting that they are not real astrophysical signals. Our forward-model analysis rules out a low-mean-molecular-weight atmosphere (<350× solar metallicity) to at least 3 σ , and disfavors CH _4 -dominated atmospheres at 1–3 σ , depending on the reduction. Instead, the forward models find our transmission spectra are consistent with no atmosphere, a hazy atmosphere, or an atmosphere containing a species that does not have prominent molecular bands across the NIRCam/F444W bandpass, such as a water-dominated atmosphere. Our results demonstrate the unequivocal need for two or more transit observations analyzed with multiple reduction pipelines, alongside rigorous statistical tests, to determine the robustness of molecular detections for small exoplanet atmospheres.https://doi.org/10.3847/1538-3881/ad19dfExtrasolar rocky planetsExoplanets |
| spellingShingle | James Kirk Kevin B. Stevenson Guangwei Fu Jacob Lustig-Yaeger Sarah E. Moran Sarah Peacock Munazza K. Alam Natasha E. Batalha Katherine A. Bennett Junellie Gonzalez-Quiles Mercedes López-Morales Joshua D. Lothringer Ryan J. MacDonald E. M. May L. C. Mayorga Zafar Rustamkulov David K. Sing Kristin S. Sotzen Jeff A. Valenti Hannah R. Wakeford JWST/NIRCam Transmission Spectroscopy of the Nearby Sub-Earth GJ 341b The Astronomical Journal Extrasolar rocky planets Exoplanets |
| title | JWST/NIRCam Transmission Spectroscopy of the Nearby Sub-Earth GJ 341b |
| title_full | JWST/NIRCam Transmission Spectroscopy of the Nearby Sub-Earth GJ 341b |
| title_fullStr | JWST/NIRCam Transmission Spectroscopy of the Nearby Sub-Earth GJ 341b |
| title_full_unstemmed | JWST/NIRCam Transmission Spectroscopy of the Nearby Sub-Earth GJ 341b |
| title_short | JWST/NIRCam Transmission Spectroscopy of the Nearby Sub-Earth GJ 341b |
| title_sort | jwst nircam transmission spectroscopy of the nearby sub earth gj 341b |
| topic | Extrasolar rocky planets Exoplanets |
| url | https://doi.org/10.3847/1538-3881/ad19df |
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