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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"

16290 results found.

  1. Swift GRB191004.75: Global MASTER-Net OT detection
  2. LIGO/Virgo S190930t: AT2019rpn, AT2019rpj CrAO continued optical photometry
  3. GRB 191001A: Swift-XRT observations
  4. LIGO/Virgo S190930t: J-GEM follow-up observation for Swift J221951-484240
  5. GRB 191001B: Optical Upper Limits with LCO
  6. LIGO/Virgo S190930t: Continued Swift/UVOT observations of Swift J221951-484240
  7. GRB 191001A: Fermi GBM observation
  8. LIGO/Virgo S190930t: AT2019rpn, AT2019rpj CrAO optical photometry
  9. IPN triangulation of GRB 191001A
  10. LIGO/Virgo S190930t: J-GEM follow-up observations for AT2019rpj
  11. GRB 191001A: KAIT Optical Upper Limit
  12. GRB 191001A: RATIR Optical and NIR Observations
  13. LIGO/Virgo S190930t: Lulin Follow-up Observations of AT2019rpn and AT2019rpj
  14. GRB 191001A: DDOTI Optical Counterpart Candidate
  15. LIGO/Virgo S190930t and S190930s: MASTER OT J205529.78+220725.5/AT2019rpr further analysis
  16. LIGO/Virgo S190930t: Upper limits on the two of the ZTF/GROWTH candidates
  17. GRB 191001B: MITSuME Akeno optical upper limits
  18. LIGO/Virgo S190923y: optical spectrum of MASTER detected transient
  19. LIGO/Virgo S190930t and S190930s: MASTER optical observation and optical transient
  20. GRB 190928A: MASTER optical observations
  21. GRB 190926A: AbAO upper optical limit
  22. LIGO/Virgo S190923y: MASTER OT outburst detection inside NSBH merger error-box
  23. GRB 190926A: MITSuME Akeno optical upper limits
  24. GRB 190926A: Swift/UVOT Upper Limits
  25. GRB 190926A: KAIT Optical Upper Limit
  26. LIGO/Virgo S190814bv: Chandra X-ray non-detection of ASKAP J005547-270433 / AT2019osy
  27. LIGO/Virgo S190814bv: HST and ALMA observations of the host galaxy of ASKAP J005547-270433 / AT 2019osy
  28. GRB 190919B: BOOTES-5/JGT and BOOTES-3/YA optical observations
  29. GRB 190919B: LCO Optical Afterglow Detection
  30. GRB 190919B: Swift/UVOT Upper Limits
  31. GRB 190919B: FRAM-Auger optical detection
  32. GRB 190919B: VLT/X-shooter redshift
  33. GRB 190919B: MASTER OT early detection at GROND position
  34. LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019nte host galaxy
  35. HAWC-190916A: DDOTI Optical Observations
  36. GRB190915A: MASTER optical observation of BALROG Fermi GRB localization
  37. LIGO/Virgo S190910h: WHT spectroscopy of Gaia19ebl, Gaia19eba, Gaia19eaz
  38. LIGO/Virgo S190910d: No Counterparts in DDOTI/OAN Optical Observations
  39. LIGO/Virgo S190910h: WHT spectroscopy of AT2019pyz/PS19fbi
  40. LIGO/Virgo S190910h and S190910d: WHT photometry of ZTF candidates
  41. LIGO/Virgo S190910h: AT2019pxi, AT2019pxj and AT2019pxn 10.4m GTC spectroscopy
  42. LIGO/Virgo S190910h: WHT spectroscopy of ZTF19abygvmp/AT2019pzg
  43. LIGO/Virgo S190910h: Four additional candidates from the Zwicky Transient Facility
  44. LIGO/Virgo S190910d: WHT spectroscopy of ZTF19abyfhov, ZTF19abyfhaq, ZTF19abyfbii
  45. LIGO/Virgo S190901ap: WHT spectroscopy of Gaia19dzi
  46. LIGO/Virgo S190910d: AT2019pvu, AT2019pvv, AT2019pvz and AT2019pwa 10.4m GTC spectroscopy
  47. LIGO/Virgo S190910d: Liverpool Telescope spectroscopy of ZTF19abyfazm
  48. ZTF19abvizsw: AbAO and CrAO photometry
  49. GRB 190829A observations in CrAO, photometry of the SN
  50. LIGO/Virgo S190901ap: ZTF19abwvals is a type-Ia SN near maximum
  51. LIGO/Virgo S190901ap: Second Epoch Hobby-Eberly Telescope observations of ZTF19abvionh
  52. GRB 180620A: SEDM Observations
  53. GRB 190829A optical observation
  54. LIGO/Virgo S190901ap: NOT spectroscopy of AT2019pjv
  55. GRB190829A: Keck LRIS spectroscopic confirmation of the accompanying supernova
  56. LIGO/Virgo S190901ap: No counterpart candidates in KAIT observations
  57. LIGO/Virgo S190901ap : GRAWITA spectroscopic observation of candidate MASTER OT J171434.95+280725.6
  58. LIGO/Virgo S190901ap: Dabancheng-0.5m optical observations of AT2019pjv
  59. GRB 190829A: Liverpool Telescope observations of a slow supernova rise
  60. ZTF19abvizsw: COATLI Optical Observations
  61. LIGO/Virgo S190901ap: GOTO optical coverage and detection of AT2019pjv
  62. GRB190829A: GROND detection of the accompanying SN
  63. LIGO/Virgo S190901ap: MASTER OT J171434.95+280725.6/AT2019pjv detection
  64. Liverpool Telescope observations of ZTF19abvizsw, a candidate untriggered GRB afterglow
  65. GRB 190829A: LCO Optical Afterglow Detection
  66. GRB 190829A: MeerKAT radio observation
  67. LIGO/Virgo S190901ap: GROWTH-India follow-up of ZTF19abvionh
  68. GRB 190829A: Detection of radio afterglow with the uGMRT
  69. GRB 190829A: Flattening of optical light curve from continued Liverpool Telescope photometry
  70. LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of ZTF19abvionh
  71. LIGO/Virgo S190901ap: Hobby-Eberly Telescope VIRUS observations of target galaxy; no obvious optical counterpart.
  72. LIGO/Virgo S190901ap : GRAWITA spectroscopic observation of candidate ZTFabvixoy
  73. LIGO/Virgo S190901ap : GRAWITA spectroscopic observation of candidate ZTFabvizsw
  74. LIGO/Virgo S190814bv : No significant candidates in TAROT-GRANDMA observations
  75. GRB 190829A: Continued fading inferred from Liverpool Telescope photometry
  76. LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidate AT2019ntp
  77. GRB 190829A: Keck LRIS spectroscopy of the optical afterglow
  78. GRB 190829A: Liverpool Telescope observations
  79. LIGO/Virgo S190814bv: AT2019odc and AT2019omt 10.4m GTC spectroscopy
  80. GRB 190829A: Liverpool Telescope optical photometry
  81. GRB 190829A: MMT detection of the optical afterglow
  82. GRB 190829A: KAIT Detection of the Optical Afterglow
  83. GRB 190829A:: Global MASTER-net optical clear and polarization observations scheduler and some spiculations
  84. LIGO/Virgo S190814bv: AT2019nqc and AT2019nqz 10.4m GTC spectroscopy
  85. GRB 190829A: Swift/UVOT detection of an optical afterglow with a rise
  86. GRB 190829A: GROND detection of the Optical/NIR Afterglow
  87. GRB 190829A: 10.4m GTC spectroscopy
  88. GRB 190829A: NOT optical afterglow detection and spectroscopy
  89. LIGO/Virgo S190828j: No Counterparts in DDOTI/OAN Optical Observations
  90. GRB 190829A: GROWTH India detection of afterglow
  91. GRB 190829A:: MASTER-net bright and decay OT detection
  92. GRB 190829A: Dabancheng-0.5m optical afterglow detection
  93. GRB 190828B: VLT/X-shooter optical afterglow candidate
  94. GRB 190828B: optical upper limit from 0.5m Savelli Robotic Telescope
  95. GRB 190828B: Swift/UVOT Upper Limits
  96. LIGO/Virgo S190814bv: AT2019nxe and AT2019obc 10.4m GTC spectroscopy
  97. LIGO/Virgo S190814bv: SOAR spectroscopy of DECam candidates AT2019ntr and AT2019omx
  98. LIGO/Virgo S190814bv: VLA observation of ASKAP J005547-270433/AT2019osy
  99. LIGO/Virgo S190814bv: Swift UVOT - no new counterpart candidates identified
  100. GRB 190828B: Dabancheng-0.5m optical upper limit

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