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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
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To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

16288 results found.

  1. GRB 191001A: Swift-XRT observations
  2. LIGO/Virgo S190930t: J-GEM follow-up observation for Swift J221951-484240
  3. GRB 191001B: Optical Upper Limits with LCO
  4. LIGO/Virgo S190930t: Continued Swift/UVOT observations of Swift J221951-484240
  5. GRB 191001A: Fermi GBM observation
  6. LIGO/Virgo S190930t: AT2019rpn, AT2019rpj CrAO optical photometry
  7. IPN triangulation of GRB 191001A
  8. LIGO/Virgo S190930t: J-GEM follow-up observations for AT2019rpj
  9. GRB 191001A: KAIT Optical Upper Limit
  10. GRB 191001A: RATIR Optical and NIR Observations
  11. LIGO/Virgo S190930t: Lulin Follow-up Observations of AT2019rpn and AT2019rpj
  12. GRB 191001A: DDOTI Optical Counterpart Candidate
  13. LIGO/Virgo S190930t and S190930s: MASTER OT J205529.78+220725.5/AT2019rpr further analysis
  14. LIGO/Virgo S190930t: Upper limits on the two of the ZTF/GROWTH candidates
  15. GRB 191001B: MITSuME Akeno optical upper limits
  16. LIGO/Virgo S190923y: optical spectrum of MASTER detected transient
  17. LIGO/Virgo S190930t and S190930s: MASTER optical observation and optical transient
  18. GRB 190928A: MASTER optical observations
  19. GRB 190926A: AbAO upper optical limit
  20. LIGO/Virgo S190923y: MASTER OT outburst detection inside NSBH merger error-box
  21. GRB 190926A: MITSuME Akeno optical upper limits
  22. GRB 190926A: Swift/UVOT Upper Limits
  23. GRB 190926A: KAIT Optical Upper Limit
  24. LIGO/Virgo S190814bv: Chandra X-ray non-detection of ASKAP J005547-270433 / AT2019osy
  25. LIGO/Virgo S190814bv: HST and ALMA observations of the host galaxy of ASKAP J005547-270433 / AT 2019osy
  26. GRB 190919B: BOOTES-5/JGT and BOOTES-3/YA optical observations
  27. GRB 190919B: LCO Optical Afterglow Detection
  28. GRB 190919B: Swift/UVOT Upper Limits
  29. GRB 190919B: FRAM-Auger optical detection
  30. GRB 190919B: VLT/X-shooter redshift
  31. GRB 190919B: MASTER OT early detection at GROND position
  32. LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019nte host galaxy
  33. HAWC-190916A: DDOTI Optical Observations
  34. GRB190915A: MASTER optical observation of BALROG Fermi GRB localization
  35. LIGO/Virgo S190910h: WHT spectroscopy of Gaia19ebl, Gaia19eba, Gaia19eaz
  36. LIGO/Virgo S190910d: No Counterparts in DDOTI/OAN Optical Observations
  37. LIGO/Virgo S190910h: WHT spectroscopy of AT2019pyz/PS19fbi
  38. LIGO/Virgo S190910h and S190910d: WHT photometry of ZTF candidates
  39. LIGO/Virgo S190910h: AT2019pxi, AT2019pxj and AT2019pxn 10.4m GTC spectroscopy
  40. LIGO/Virgo S190910h: WHT spectroscopy of ZTF19abygvmp/AT2019pzg
  41. LIGO/Virgo S190910h: Four additional candidates from the Zwicky Transient Facility
  42. LIGO/Virgo S190910d: WHT spectroscopy of ZTF19abyfhov, ZTF19abyfhaq, ZTF19abyfbii
  43. LIGO/Virgo S190901ap: WHT spectroscopy of Gaia19dzi
  44. LIGO/Virgo S190910d: AT2019pvu, AT2019pvv, AT2019pvz and AT2019pwa 10.4m GTC spectroscopy
  45. LIGO/Virgo S190910d: Liverpool Telescope spectroscopy of ZTF19abyfazm
  46. ZTF19abvizsw: AbAO and CrAO photometry
  47. GRB 190829A observations in CrAO, photometry of the SN
  48. LIGO/Virgo S190901ap: ZTF19abwvals is a type-Ia SN near maximum
  49. LIGO/Virgo S190901ap: Second Epoch Hobby-Eberly Telescope observations of ZTF19abvionh
  50. GRB 180620A: SEDM Observations
  51. GRB 190829A optical observation
  52. LIGO/Virgo S190901ap: NOT spectroscopy of AT2019pjv
  53. GRB190829A: Keck LRIS spectroscopic confirmation of the accompanying supernova
  54. LIGO/Virgo S190901ap: No counterpart candidates in KAIT observations
  55. LIGO/Virgo S190901ap : GRAWITA spectroscopic observation of candidate MASTER OT J171434.95+280725.6
  56. LIGO/Virgo S190901ap: Dabancheng-0.5m optical observations of AT2019pjv
  57. GRB 190829A: Liverpool Telescope observations of a slow supernova rise
  58. ZTF19abvizsw: COATLI Optical Observations
  59. LIGO/Virgo S190901ap: GOTO optical coverage and detection of AT2019pjv
  60. GRB190829A: GROND detection of the accompanying SN
  61. LIGO/Virgo S190901ap: MASTER OT J171434.95+280725.6/AT2019pjv detection
  62. Liverpool Telescope observations of ZTF19abvizsw, a candidate untriggered GRB afterglow
  63. GRB 190829A: LCO Optical Afterglow Detection
  64. GRB 190829A: MeerKAT radio observation
  65. LIGO/Virgo S190901ap: GROWTH-India follow-up of ZTF19abvionh
  66. GRB 190829A: Detection of radio afterglow with the uGMRT
  67. GRB 190829A: Flattening of optical light curve from continued Liverpool Telescope photometry
  68. LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of ZTF19abvionh
  69. LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of target galaxy; no obvious optical counterpart.
  70. LIGO/Virgo S190901ap : GRAWITA spectroscopic observation of candidate ZTFabvixoy
  71. LIGO/Virgo S190901ap : GRAWITA spectroscopic observation of candidate ZTFabvizsw
  72. LIGO/Virgo S190814bv : No significant candidates in TAROT-GRANDMA observations
  73. GRB 190829A: Continued fading inferred from Liverpool Telescope photometry
  74. LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidate AT2019ntp
  75. GRB 190829A: Keck LRIS spectroscopy of the optical afterglow
  76. GRB 190829A: Liverpool Telescope observations
  77. LIGO/Virgo S190814bv: AT2019odc and AT2019omt 10.4m GTC spectroscopy
  78. GRB 190829A: Liverpool Telescope optical photometry
  79. GRB 190829A: MMT detection of the optical afterglow
  80. GRB 190829A: KAIT Detection of the Optical Afterglow
  81. GRB 190829A:: Global MASTER-net optical clear and polarization observations scheduler and some spiculations
  82. LIGO/Virgo S190814bv: AT2019nqc and AT2019nqz 10.4m GTC spectroscopy
  83. GRB 190829A: Swift/UVOT detection of an optical afterglow with a rise
  84. GRB 190829A: GROND detection of the Optical/NIR Afterglow
  85. GRB 190829A: 10.4m GTC spectroscopy
  86. GRB 190829A: NOT optical afterglow detection and spectroscopy
  87. LIGO/Virgo S190828j: No Counterparts in DDOTI/OAN Optical Observations
  88. GRB 190829A: GROWTH India detection of afterglow
  89. GRB 190829A:: MASTER-net bright and decay OT detection
  90. GRB 190829A: Dabancheng-0.5m optical afterglow detection
  91. GRB 190828B: VLT/X-shooter optical afterglow candidate
  92. GRB 190828B: optical upper limit from 0.5m Savelli Robotic Telescope
  93. GRB 190828B: Swift/UVOT Upper Limits
  94. LIGO/Virgo S190814bv: AT2019nxe and AT2019obc 10.4m GTC spectroscopy
  95. LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019ntr and AT2019omx
  96. LIGO/Virgo S190814bv: VLA observation of ASKAP J005547-270433/AT2019osy
  97. LIGO/Virgo S190814bv: Swift UVOT - no new counterpart candidates identified
  98. GRB 190828B: Dabancheng-0.5m optical upper limit
  99. LIGO/Virgo S190814bv: DESGW non-detection of AT2019osy/ASKAP 005547-270433
  100. LIGO/Virgo S190814bv: Palomar 200-in spectroscopic redshift and host galaxy properties of ASKAP source AT2019osy

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