J/MNRAS/497/5182 WASP-21b light curves (Alderson+, 2020)
LRG-BEASTS: ground-based detection of sodium and a steep optical slope in the
atmosphere of the highly inflated hot-saturn WASP-21b.
Alderson L., Kirk J., Lopez-Morales M., Wheatley P.J., Skillen I.,
Henry G.W., McGruder C., Brogi M., Louden T., King G.
<Mon. Not. R. Astron. Soc. 497, 5182-5202 (2020)>
=2020MNRAS.497.5182A 2020MNRAS.497.5182A (SIMBAD/NED BibCode)
ADC_Keywords: Stars, double and multiple ; Exoplanets ; Spectra, optical
Keywords: techniques: spectroscopic -
planets and satellites: atmosphereites: atmospheres -
planets and satellites: gaseous planets -
planets and satellites: individual: WASP-21b
Abstract:
We present the optical transmission spectrum of the highly inflated
Saturn- mass exoplanet WASP-21b, using three transits obtained with
the ACAM instrument on the William Herschel Telescope through the
LRG-BEASTS survey (Low Resolution Ground-Based Exoplanet Atmosphere
Survey using Transmission Spectroscopy). Our transmission spectrum
covers a wavelength range of 4635-9000Å, achieving an average
transit depth precision of 197ppm compared to one atmospheric scale
height at 246ppm. We detect NaI absorption in a bin width of 30Å,
at >4σ confidence, which extends over 100Å. We see no
evidence of absorption from KI. Atmospheric retrieval analysis of the
scattering slope indicates it is too steep for Rayleigh scattering
from H_2, but is very similar to that of HD 189733b. The features
observed in our transmission spectrum cannot be caused by stellar
activity alone, with photometric monitoring of WASP-21 showing it to
be an inactive star. We therefore conclude that aerosols in the
atmosphere of WASP-21b are giving rise to the steep slope that we
observe, and that WASP-21b is an excellent target for infra-red
observations to constrain its atmospheric metallicity.
Description:
These tables contain the white light and wavelength binned light
curves of the three transits of WASP-21b observed with the ACAM
instrument on the William Herschel Telescope on the nights of 2017
September 09 and 22 and 2018 September 20.
Objects:
------------------------------------------------------------
RA (2000) DE Designation(s)
------------------------------------------------------------
23 09 58.2 +18 23 45 WASP-21b = 2MASS J23095825+1823459
------------------------------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
wlc-n1.dat 59 154 Reduced white light curve from night 1
with time
wlc-n2.dat 80 68 Reduced white light curve from night 2
with time and FWHM
wlc-n3.dat 80 135 Reduced white light curve from night 3
with time and FWHM
slc-n1.dat 1058 154 Reduced binned light curve from night 1
with time
slc-n2.dat 1080 68 Reduced binned light curve from night 2
with time and FWHM
slc-n3.dat 1640 135 Reduced binned light curve from night 3
with FWHM and sky background
--------------------------------------------------------------------------------
See also:
J/A+A/519/A98 : Transit of exoplanet WASP-21b (Bouchy+, 2010)
Byte-by-byte Description of file: wlc-n1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Row Row number
5- 17 F13.7 d MJD Modified Julian Date
19- 36 F18.16 --- Flux Normalised white light flux
38- 59 E22.16 --- e_Flux Normalised white light error
--------------------------------------------------------------------------------
Byte-by-byte Description of file: wlc-n2.dat wlc-n3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Row Row number
5- 17 F13.7 d MJD Modified Julian Date
19- 39 F21.18 --- FWHM Full width half maximum
41- 58 F18.16 --- Flux Normalised white light flux
60- 80 E21.16 --- e_Flux Normalised white light error
--------------------------------------------------------------------------------
Byte-by-byte Description of file: slc-n1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Row Row number
5- 17 F13.7 d MJD Modified Julian Date
19- 36 F18.16 --- Flux1 Normalised flux in 270Å-wide bin
centred on 4635Å
38- 58 F21.19 --- e_Flux1 Normalised error in 270Å-wide bin
centred on 4635Å
60- 77 F18.16 --- Flux2 Normalised flux in 180Å-wide bin
centred on 4860Å
79- 99 F21.19 --- e_Flux2 Normalised error in 180Å-wide bin
centred on 4860Å
101- 118 F18.16 --- Flux3 Normalised flux in 280Å-wide bin
centred on 5090Å
120- 141 F22.20 --- e_Flux3 Normalised error in 280Å-wide bin
centred on 5090Å
143- 160 F18.16 --- Flux4 Normalised flux in 250Å-wide bin
centred on 5355Å
162- 183 F22.20 --- e_Flux4 Normalised error in 250Å-wide bin
centred on 5355Å
185- 202 F18.16 --- Flux5 Normalised flux in 218Å-wide bin
centred on 5589Å
204- 225 F22.20 --- e_Flux5 Normalised error in 218Å-wide bin
centred on 5589Å
227- 244 F18.16 --- Flux6 Normalised flux in 70Å-wide bin
centred on 5733Å
246- 266 F21.19 --- e_Flux6 Normalised error in 70Å-wide bin
centred on 5733Å
268- 285 F18.16 --- Flux7 Normalised flux in 60Å-wide bin
centred on 5798Å
287- 307 F21.19 --- e_Flux7 Normalised error in 60Å-wide bin
centred on 5798Å
309- 326 F18.16 --- Flux8 Normalised flux in 50Å-wide bin
centred on 5853Å
328- 348 F21.19 --- e_Flux8 Normalised error in 50Å-wide bin
centred on 5853Å
350- 367 F18.16 --- Flux9 Normalised flux in 30Å-wide bin
centred on 5893Å
369- 389 F21.19 --- e_Flux9 Normalised error in 30Å-wide bin
centred on 5893Å
391- 408 F18.16 --- Flux10 Normalised flux in 50Å-wide bin
centred on 5933Å
410- 430 F21.19 --- e_Flux10 Normalised error in 50Å-wide bin
centred on 5933Å
432- 449 F18.16 --- Flux11 Normalised flux in 60Å-wide bin
centred on 5988Å
451- 471 F21.19 --- e_Flux11 Normalised error in 60Å-wide bin
centred on 5988Å
473- 490 F18.16 --- Flux12 Normalised flux in 70Å-wide bin
centred on 6053Å
492- 512 F21.19 --- e_Flux12 Normalised error in 70Å-wide bin
centred on 6053Å
514- 531 F18.16 --- Flux13 Normalised flux in 142Å-wide bin
centred on 6159Å
533- 554 F22.20 --- e_Flux13 Normalised error in 142Å-wide bin
centred on 6159Å
556- 573 F18.16 --- Flux14 Normalised flux in 200Å-wide bin
centred on 6330Å
575- 596 F22.20 --- e_Flux14 Normalised error in 200Å-wide bin
centred on 6330Å
598- 615 F18.16 --- Flux15 Normalised flux in 300Å-wide bin
centred on 6580Å
617- 638 F22.20 --- e_Flux15 Normalised error in 300Å-wide bin
centred on 6580Å
640- 657 F18.16 --- Flux16 Normalised flux in 250Å-wide bin
centred on 6855Å
659- 680 F22.20 --- e_Flux16 Normalised error in 250Å-wide bin
centred on 6855Å
682- 699 F18.16 --- Flux17 Normalised flux in 135Å-wide bin
centred on 7047Å
701- 722 F22.20 --- e_Flux17 Normalised error in 135Å-wide bin
centred on 7047Å
724- 741 F18.16 --- Flux18 Normalised flux in 255Å-wide bin
centred on 7242Å
743- 764 F22.20 --- e_Flux18 Normalised error in 255Å-wide bin
centred on 7242Å
766- 783 F18.16 --- Flux19 Normalised flux in 150Å-wide bin
centred on 7445Å
785- 806 F22.20 --- e_Flux19 Normalised error in 150Å-wide bin
centred on 7445Å
808- 825 F18.16 --- Flux20 Normalised flux in 350Å-wide bin
centred on 7695Å
827- 848 F22.20 --- e_Flux20 Normalised error in 350Å-wide bin
centred on 7695Å
850- 867 F18.16 --- Flux21 Normalised flux in 200Å-wide bin
centred on 7970Å
869- 890 F22.20 --- e_Flux21 Normalised error in 200Å-wide bin
centred on 7970Å
892- 909 F18.16 --- Flux22 Normalised flux in 300Å-wide bin
centred on 8220Å
911- 932 F22.20 --- e_Flux22 Normalised error in 300Å-wide bin
centred on 8220Å
934- 951 F18.16 --- Flux23 Normalised flux in 230Å-wide bin
centred on 8485Å
953- 974 F22.20 --- e_Flux23 Normalised error in 230Å-wide bin
centred on 8485Å
976- 993 F18.16 --- Flux24 Normalised flux in 200Å-wide bin
centred on 8700Å
995-1016 F22.20 --- e_Flux24 Normalised error in 200Å-wide bin
centred on 8700Å
1018-1035 F18.16 --- Flux25 Normalised flux in 400Å-wide bin
centred on 9000Å
1037-1058 F22.20 --- e_Flux25 Normalised error in 400Å-wide bin
centred on 9000Å
--------------------------------------------------------------------------------
Byte-by-byte Description of file: slc-n2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Row Row number
5- 17 F13.7 d MJD Modified Julian Date
19- 39 F21.18 --- FWHM Full width half maximum
41- 58 F18.16 --- Flux1 Normalised flux in 270Å-wide bin
centred on 4635Å
60- 80 F21.19 --- e_Flux1 Normalised error in 270Å-wide bin
centred on 4635Å
82- 99 F18.16 --- Flux2 Normalised flux in 180Å-wide bin
centred on 4860Å
101- 121 F21.19 --- e_Flux2 Normalised error in 180Å-wide bin
centred on 4860Å
123- 140 F18.16 --- Flux3 Normalised flux in 280Å-wide bin
centred on 5090Å
142- 163 F22.20 --- e_Flux3 Normalised error in 280Å-wide bin
centred on 5090Å
165- 182 F18.16 --- Flux4 Normalised flux in 250Å-wide bin
centred on 5355Å
184- 205 F22.20 --- e_Flux4 Normalised error in 250Å-wide bin
centred on 5355Å
207- 224 F18.16 --- Flux5 Normalised flux in 218Å-wide bin
centred on 5589Å
226- 247 F22.20 --- e_Flux5 Normalised error in 218Å-wide bin
centred on 5589Å
249- 266 F18.16 --- Flux6 Normalised flux in 70Å-wide bin
centred on 5733Å
268- 288 F21.19 --- e_Flux6 Normalised error in 70Å-wide bin
centred on 5733Å
290- 307 F18.16 --- Flux7 Normalised flux in 60Å-wide bin
centred on 5798Å
309- 329 F21.19 --- e_Flux7 Normalised error in 60Å-wide bin
centred on 5798Å
331- 348 F18.16 --- Flux8 Normalised flux in 50Å-wide bin
centred on 5853Å
350- 370 F21.19 --- e_Flux8 Normalised error in 50Å-wide bin
centred on 5853Å
372- 389 F18.16 --- Flux9 Normalised flux in 30Å-wide bin
centred on 5893Å
391- 411 F21.19 --- e_Flux9 Normalised error in 30Å-wide bin
centred on 5893Å
413- 430 F18.16 --- Flux10 Normalised flux in 50Å-wide bin
centred on 5933Å
432- 452 F21.19 --- e_Flux10 Normalised error in 50Å-wide bin
centred on 5933Å
454- 471 F18.16 --- Flux11 Normalised flux in 60Å-wide bin
centred on 5988Å
473- 493 F21.19 --- e_Flux11 Normalised error in 60Å-wide bin
centred on 5988Å
495- 512 F18.16 --- Flux12 Normalised flux in 70Å-wide bin
centred on 6053Å
514- 534 F21.19 --- e_Flux12 Normalised error in 70Å-wide bin
centred on 6053Å
536- 553 F18.16 --- Flux13 Normalised flux in 142Å-wide bin
centred on 6159Å
555- 576 F22.20 --- e_Flux13 Normalised error in 142Å-wide bin
centred on 6159Å
578- 595 F18.16 --- Flux14 Normalised flux in 200Å-wide bin
centred on 6330Å
597- 618 F22.20 --- e_Flux14 Normalised error in 200Å-wide bin
centred on 6330Å
620- 637 F18.16 --- Flux15 Normalised error in 300Å-wide bin
centred on 6580Å
639- 660 F22.20 --- e_Flux15 Normalised flux in 300Å-wide bin
centred on 6580Å
662- 679 F18.16 --- Flux16 Normalised flux in 250Å-wide bin
centred on 6855Å
681- 702 F22.20 --- e_Flux16 Normalised error in 250Å-wide bin
centred on 6855Å
704- 721 F18.16 --- Flux17 Normalised flux in 135Å-wide bin
centred on 7047Å
723- 744 F22.20 --- e_Flux17 Normalised error in 135Å-wide bin
centred on 7047Å
746- 763 F18.16 --- Flux18 Normalised flux in 255Å-wide bin
centred on 7242Å
765- 786 F22.20 --- e_Flux18 Normalised error in 255Å-wide bin
centred on 7242Å
788- 805 F18.16 --- Flux19 Normalised flux in 150Å-wide bin
centred on 7445Å
807- 828 F22.20 --- e_Flux19 Normalised error in 150Å-wide bin
centred on 7445Å
830- 847 F18.16 --- Flux20 Normalised flux in 350Å-wide bin
centred on 7695Å
849- 870 F22.20 --- e_Flux20 Normalised error in 350Å-wide bin
centred on 7695Å
872- 889 F18.16 --- Flux21 Normalised flux in 200Å-wide bin
centred on 7970Å
891- 912 F22.20 --- e_Flux21 Normalised error in 200Å-wide bin
centred on 7970Å
914- 931 F18.16 --- Flux22 Normalised flux in 300Å-wide bin
centred on 8220Å
933- 954 F22.20 --- e_Flux22 Normalised error in 300Å-wide bin
centred on 8220Å
956- 973 F18.16 --- Flux23 Normalised flux in 230Å-wide bin
centred on 8485Å
975- 996 F22.20 --- e_Flux23 Normalised error in 230Å-wide bin
centred on 8485Å
998-1015 F18.16 --- Flux24 Normalised flux in 200Å-wide bin
centred on 8700Å
1017-1038 F22.20 --- e_Flux24 Normalised error in 200Å-wide bin
centred on 8700Å
1040-1057 F18.16 --- Flux25 Normalised flux in 400Å-wide bin
centred on 9000Å
1059-1080 F22.20 --- e_Flux25 Normalised error in 400Å-wide bin
centred on 9000Å
--------------------------------------------------------------------------------
Byte-by-byte Description of file: slc-n3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Row Row number
5- 15 F11.5 d MJD Modified Julian Date
17- 37 F21.18 --- FWHM Full width half maximum
39- 60 F22.19 --- Sky1 Sky background in 270Å-wide bin
centred on 4635Å
62- 79 F18.16 --- Flux1 Normalised flux in 270Å-wide bin
centred on 4635Å
81- 101 F21.19 --- e_Flux1 Normalised error in 270Å-wide bin
centred on 4635Å
103- 125 F23.20 --- Sky2 Sky background in 180Å-wide bin
centred on 4860Å
127- 144 F18.16 --- Flux2 Normalised flux in 180Å-wide bin
centred on 4860Å
146- 166 F21.19 --- e_Flux2 Normalised error in 180Å-wide bin
centred on 4860Å
168- 188 F21.18 --- Sky3 Sky background in 280Å-wide bin
centred on 5090Å
190- 207 F18.16 --- Flux3 Normalised flux in 280Å-wide bin
centred on 5090Å
209- 230 F22.20 --- e_Flux3 Normalised error in 280Å-wide bin
centred on 5090Å
232- 252 F21.18 --- Sky4 Sky background in 250Å-wide bin
centred on 5355Å
254- 271 F18.16 --- Flux4 Normalised flux in 250Å-wide bin
centred on 5355Å
273- 294 F22.20 --- e_Flux4 Normalised error in 250Å-wide bin
centred on 5355Å
296- 317 F22.19 --- Sky5 Sky background in 218Å-wide bin
centred on 5589Å
319- 336 F18.16 --- Flux5 Normalised flux in 218Å-wide bin
centred on 5589Å
338- 359 F22.20 --- e_Flux5 Normalised error in 218Å-wide bin
centred on 5589Å
361- 381 F21.18 --- Sky6 Sky background in 70Å-wide bin
centred on 5733Å
383- 400 F18.16 --- Flux6 Normalised flux in 70Å-wide bin
centred on 5733Å
402- 422 F21.19 --- e_Flux6 Normalised error in 70Å-wide bin
centred on 5733Å
424- 444 F21.18 --- Sky7 Sky background in 60Å-wide bin
centred on 5798Å
446- 463 F18.16 --- Flux7 Normalised flux in 60Å-wide bin
centred on 5798Å
465- 485 F21.19 --- e_Flux7 Normalised error in 60Å-wide bin
centred on 5798Å
487- 508 F22.19 --- Sky8 Sky background in 50Å-wide bin
centred on 5853Å
510- 527 F18.16 --- Flux8 Normalised flux in 50Å-wide bin
centred on 5853Å
529- 549 F21.19 --- e_Flux8 Normalised error in 50Å-wide bin
centred on 5853Å
551- 571 F21.18 --- Sky9 Sky background in 30Å-wide bin
centred on 5893Å
573- 590 F18.16 --- Flux9 Normalised flux in 30Å-wide bin
centred on 5893Å
592- 612 F21.19 --- e_Flux9 Normalised error in 30Å-wide bin
centred on 5893Å
614- 635 F22.19 --- Sky10 Sky background in 50Å-wide bin
centred on 5933Å
637- 654 F18.16 --- Flux10 Normalised flux in 50Å-wide bin
centred on 5933Å
656- 676 F21.19 --- e_Flux10 Normalised error in 50Å-wide bin
centred on 5933Å
678- 699 F22.19 --- Sky11 Sky background in 60Å-wide bin
centred on 5988Å
701- 718 F18.16 --- Flux11 Normalised flux in 60Å-wide bin
centred on 5988Å
720- 740 F21.19 --- e_Flux11 Normalised error in 60Å-wide bin
centred on 5988Å
742- 762 F21.18 --- Sky12 Sky background in 70Å-wide bin
centred on 6053Å
764- 781 F18.16 --- Flux12 Normalised flux in 70Å-wide bin
centred on 6053Å
783- 803 F21.19 --- e_Flux12 Normalised error in 70Å-wide bin
centred on 6053Å
805- 825 F21.18 --- Sky13 Sky background in 142Å-wide bin
centred on 6159Å
827- 844 F18.16 --- Flux13 Normalised flux in 142Å-wide bin
centred on 6159Å
846- 867 F22.20 --- e_Flux13 Normalised error in 142Å-wide bin
centred on 6159Å
869- 889 F21.18 --- Sky14 Sky background in 200Å-wide bin
centred on 6330Å
891- 908 F18.16 --- Flux14 Normalised flux in 200Å-wide bin
centred on 6330Å
910- 931 F22.20 --- e_Flux14 Normalised error in 200Å-wide bin
centred on 6330Å
933- 954 F22.19 --- Sky15 Sky background in 300Å-wide bin
centred on 6580Å
956- 973 F18.16 --- Flux15 Normalised flux in 300Å-wide bin
centred on 6580Å
975- 996 F22.20 --- e_Flux15 Normalised error in 300Å-wide bin
centred on 6580Å
998-1018 F21.18 --- Sky16 Sky background in 250Å-wide bin
centred on 6855Å
1020-1037 F18.16 --- Flux16 Normalised flux in 250Å-wide bin
centred on 6855Å
1039-1060 F22.20 --- e_Flux16 Normalised error in 250Å-wide bin
centred on 6855Å
1062-1082 F21.18 --- Sky17 Sky background in 135Å-wide bin
centred on 7047Å
1084-1101 F18.16 --- Flux17 Normalised flux in 135Å-wide bin
centred on 7047Å
1103-1124 F22.20 --- e_Flux17 Normalised error in 135Å-wide bin
centred on 7047Å
1126-1145 F20.17 --- Sky18 Sky background in 255Å-wide bin
centred on 7242Å
1147-1164 F18.16 --- Flux18 Normalised flux in 255Å-wide bin
centred on 7242Å
1166-1187 F22.20 --- e_Flux18 Normalised error in 255Å-wide bin
centred on 7242Å
1189-1211 F23.20 --- Sky19 Sky background in 150Å-wide bin
centred on 7445Å
1213-1230 F18.16 --- Flux19 Normalised flux in 150Å-wide bin
centred on 7445Å
1232-1253 F22.20 --- e_Flux19 Normalised error in 150Å-wide bin
centred on 7445Å
1255-1276 F22.19 --- Sky20 Sky background in 350Å-wide bin
centred on 7695Å
1278-1295 F18.16 --- Flux20 Normalised flux in 350Å-wide bin
centred on 7695Å
1297-1318 F22.20 --- e_Flux20 Normalised error in 350Å-wide bin
centred on 7695Å
1320-1341 F22.19 --- Sky21 Sky background in 200Å-wide bin
centred on 7970Å
1343-1360 F18.16 --- Flux21 Normalised flux in 200Å-wide bin
centred on 7970Å
1362-1383 F22.20 --- e_Flux21 Normalised error in 200Å-wide bin
centred on 7970Å
1385-1405 F21.18 --- Sky22 Sky background in 300Å-wide bin
centred on 8220Å
1407-1424 F18.16 --- Flux22 Normalised flux in 300Å-wide bin
centred on 8220Å
1426-1447 F22.20 --- e_Flux22 Normalised error in 300Å-wide bin
centred on 8220Å
1449-1469 F21.18 --- Sky23 Sky background in 230Å-wide bin
centred on 8485Å
1471-1488 F18.16 --- Flux23 Normalised flux in 230Å-wide bin
centred on 8485Å
1490-1511 F22.20 --- e_Flux23 Normalised error in 230Å-wide bin
centred on 8485Å
1513-1533 F21.18 --- Sky24 Sky background in 200Å-wide bin
centred on 8700Å
1535-1552 F18.16 --- Flux24 Normalised flux in 200Å-wide bin
centred on 8700Å
1554-1575 F22.20 --- e_Flux24 Normalised error in 200Å-wide bin
centred on 8700Å
1577-1598 F22.19 --- Sky25 Sky background in 400Å-wide bin
centred on 9000Å
1600-1617 F18.16 --- Flux25 Normalised flux in 400Å-wide bin
centred on 9000Å
1619-1640 F22.20 --- e_Flux25 Normalised error in 400Å-wide bin
centred on 9000Å
--------------------------------------------------------------------------------
Acknowledgements:
Lili Alderson, lili.alderson(at)cfa.harvard.edu
(End) Lili Alderson [Southampton Univ,, UK], Patricia Vannier [CDS] 21-Aug-2020