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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"

21106 results found.

  1. GRB 191004B: Optical Afterglow Detection with LCO
  2. Swift GRB191004.9: Global MASTER-Net OT detection
  3. LIGO/Virgo S190930t: AT2019rpn, AT2019rpj CrAO continued optical photometry
  4. GRB 191001A: Swift-XRT observations
  5. LIGO/Virgo S190930t: J-GEM follow-up observation for Swift J221951-484240
  6. GRB 191001B: Optical Upper Limits with LCO
  7. LIGO/Virgo S190930t: Continued Swift/UVOT observations of Swift J221951-484240
  8. LIGO/Virgo S190930t: Upper limits from Insight-HXMT/HE observations
  9. LIGO/Virgo S190930s: Upper limits from Insight-HXMT/HE observations
  10. Fermi-LAT Gamma-ray Observations of IceCube-191001A
  11. IceCube-191001A: Candidate Counterparts with the Zwicky Transient Facility
  12. IceCube-191001A: Not observable by Fermi-GBM
  13. GRB 191001A: Swift ToO observations
  14. LIGO/Virgo S190930t: Candidates from ATLAS observations and constraints on AT2019rpr and AT2019rpn
  15. LIGO/Virgo S190930t: J-GEM follow-up observations for AT2019rpj
  16. GRB 191001A: KAIT Optical Upper Limit
  17. GRB 191001A: RATIR Optical and NIR Observations
  18. LIGO/Virgo S190930t: HCT observations of ZTF19acbpsuf
  19. LIGO/Virgo S190930t: Lulin Follow-up Observations of AT2019rpn and AT2019rpj
  20. LIGO/Virgo S190930s: no counterpart candidates in SAGUARO/CSS observations
  21. LIGO/Virgo S190930s: No counterpart candidates in KAIT observations
  22. GRB 191001A: DDOTI Optical Counterpart Candidate
  23. IceCube Alert 191001.84: Global MASTER-Net observations report
  24. LIGO/Virgo S190930t: Upper limits on the two of the ZTF/GROWTH candidates
  25. LIGO/Virgo S190814bv: VLA 6 GHz observations of 75 galaxies in the 90% localization region
  26. GRB 191001B: Swift detection of a burst
  27. LIGO/Virgo S190930t and S190930s: MASTER PSN in unknown disk galaxy
  28. LIGO/Virgo S190930t: Candidates from the Zwicky Transient Facility
  29. LIGO/Virgo S190930t: No counterpart candidates in Fermi-LAT observations
  30. LIGO/Virgo S190930t and S190930s: MASTER optical observation and optical transient
  31. Fermi trigger No 591604915: Global MASTER-Net observations report
  32. LIGO/Virgo S190930s: No counterpart candidates in Fermi-LAT observations
  33. LIGO/Virgo S190930t: Upper limits from CALET observations.
  34. LIGO/Virgo S190930s: Upper limits from CALET observations.
  35. LIGO/Virgo S190930t: Coverage and upper limits from MAXI/GSC observations
  36. LIGO/Virgo S190930s: no counterpart candidates in the Swift/BAT observations
  37. LIGO/Virgo S190930t: no counterpart candidates in the Swift/BAT observations
  38. LIGO/Virgo S190930t: Upper limits from Fermi-GBM Observations
  39. LIGO/Virgo S190930s: Upper limits from Fermi-GBM Observations
  40. LIGO/Virgo S190930t: No counterpart candidates in HAWC observations
  41. LIGO/Virgo S190930s: no counterpart candidates in AGILE-GRID observations
  42. LIGO/Virgo S190930s: No counterpart candidates in AGILE-MCAL observations
  43. LIGO/Virgo S190930s: Coverage and upper limits from MAXI/GSC observations
  44. LIGO/Virgo S190930t: Global MASTER-Net observations report
  45. LIGO/Virgo S190930s: Global MASTER-Net observations report
  46. Fermi trigger No 591532362: Global MASTER-Net observations report
  47. GRB 190928A: MASTER optical observations
  48. Fermi trigger No 591391412: Global MASTER-Net observations report
  49. Baksan Neutrino Observatory Alert 190928.37: Global MASTER-Net observations report
  50. Fermi trigger No 591321287: Global MASTER-Net observations report
  51. GRB 190926A: Upper Limit from OSN T150 Observation
  52. LIGO/Virgo S190923y: MASTER OT outburst detection inside NSBH merger error-box
  53. GRB 190926A: Swift/UVOT Upper Limits
  54. GRB 190926A: KAIT Optical Upper Limit
  55. Swift GRB190926.41: Global MASTER-Net observations report
  56. LIGO/Virgo S190923y: No significant candidates in TAROT-GRANDMA observations
  57. LIGO/Virgo S190923y: no counterpart candidates in the Swift/BAT observations
  58. LIGO/Virgo S190924h: No counterpart candidates in Fermi-LAT observations
  59. LIGO/Virgo S190924h: no counterpart candidates in the Swift/BAT observations
  60. LIGO/Virgo S190924h: Upper limits from Fermi-GBM Observations
  61. LIGO/Virgo S190924h: no counterpart candidates in AGILE-GRID observations
  62. LIGO/Virgo S190924h: No counterpart candidates in AGILE-MCAL observations
  63. Fermi-LAT Gamma-ray Observations of IceCube-190922B
  64. LIGO/Virgo S190924h: Coverage and upper limits from MAXI/GSC observations
  65. LIGO/Virgo S190923y: No counterpart candidates in Fermi-LAT observations
  66. LIGO/Virgo S190924h: Global MASTER-Net observations report
  67. LIGO/Virgo S190923y: Upper limits from CALET observations.
  68. Fermi-LAT Gamma-ray Observations of IceCube-190922A
  69. LIGO/Virgo S190923y: INTEGRAL IBIS coded-masked imaging observations of part of the localization area and further all-sky upper limits
  70. IceCube-190922B: Identification of a Candidate Supernova from the Zwicky Transient Facility
  71. LIGO/Virgo S190923y: Upper limits from Fermi-GBM Observations
  72. LIGO/Virgo S190814bv: Chandra X-ray non-detection of ASKAP J005547-270433 / AT2019osy
  73. LIGO/Virgo S190923y: Upper limits from AGILE-GRID observations
  74. LIGO/Virgo S190923y: No counterpart candidates in AGILE-MCAL observations
  75. LIGO/Virgo S190923y: Coverage and upper limits from MAXI/GSC observations
  76. LIGO/Virgo S190923y: No counterpart candidates in HAWC observations
  77. LIGO/Virgo S190923y: Global MASTER-Net observations report
  78. Fermi trigger No 590899086: Global MASTER-Net observations report
  79. IceCube-190922B: INTEGRAL was inactive at the time of the event
  80. IceCube-190922B: Upper limits from Fermi-GBM Observations
  81. IceCube-190922A: Upper limits from Fermi-GBM Observations
  82. IceCube Alert 190922.96: Global MASTER-Net observations report
  83. LIGO/Virgo S190814bv: HST and ALMA observations of the host galaxy of ASKAP J005547-270433 / AT 2019osy
  84. Fermi trigger No 590777160: Global MASTER-Net observations report
  85. GRB 190919B: BOOTES-5/JGT and BOOTES-3/YA optical observations
  86. Baksan Neutrino Observatory Alert 190920.65: Global MASTER-Net observations report
  87. GRB 190919B: LCO Optical Afterglow Detection
  88. GRB 190919B: Swift/UVOT Upper Limits
  89. GRB 190919B: Swift-XRT observations
  90. GRB 190919B: MASTER OT early detection at GROND position
  91. GRB 190919B: Swift ToO observations
  92. GRB 190919B: GROND detection of the NIR afterglow
  93. Integral GRB190919.99: Global MASTER-Net observations report
  94. Fermi trigger No 590621700: Global MASTER-Net observations report
  95. Fermi trigger No 590610007: Global MASTER-Net observations report
  96. LIGO/Virgo S190814bv: SOAR spectroscopy of AT2019nte host galaxy
  97. LIGO/Virgo S190915ak: No significant candidates in TAROT-GRANDMA observations
  98. LIGO/Virgo S190910h: No significant candidates in TAROT-GRANDMA observations
  99. NASA GW-EM Community Survey
  100. HAWC-190916A: Upper limits from Insight-HXMT/HE observations

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