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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').
Advanced Search

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.

Advanced Search Examples (click to copy):

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

26123 results found.

  1. GRB 240523A: Swift detection of a burst
  2. GRB 240521B: Fermi GBM Observation
  3. GRB 240513A: Swift-XRT afterglow detection
  4. GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst
  5. LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
  6. LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
  7. LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
  8. GRB 240504A: VZLUSAT-2 detection
  9. GRB 240516A: Swift/UVOT Upper Limits
  10. GRB 240516A: Swift-BAT refined analysis
  11. GRB 240516A ATCA radio observations
  12. IPN triangulation of GRB 240514B (short)
  13. GRB 240513A: Swift ToO observations
  14. GRB 240516A: AstroSat CZTI detection
  15. GRB 240516A: Swift-XRT refined Analysis
  16. GRB 240514E: A possible candidate BD-21 1074
  17. GRB 240516A: Fermi GBM Observation
  18. GRB 240511A: Observations from GTC/OSIRIS+
  19. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  20. GRB 240516A: GOTO optical upper limit
  21. GRB 240516A: Swift detection of a burst
  22. Swift GRB240516.15: Global MASTER-Net observations report
  23. GRB 240511A: radio detection of afterglow candidate
  24. GRB 240514E: MAXI/GSC detection of a probable afterglow
  25. GRB 240513A: Swift-XRT observations
  26. LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
  27. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  28. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  29. GRB 240513A: Tiled Swift observations
  30. GRB 240513A: Fermi-LAT detection
  31. GRB 240511A: Fermi GBM Observation
  32. GRB 240511A: Swift-BAT refined analysis
  33. GRB 240511A: J-band observations with WINTER
  34. GRB 240511A: Enhanced Swift-XRT position
  35. GRB 240511A : MITSuME Akeno optical upper limits
  36. GRB 240511A: Swift-XRT refined Analysis
  37. GRB 240511A: optical afterglow detection from the NOT
  38. Swift GRB 240511A: Global MASTER-Net observations report
  39. GRB 240511A: Prompt enhanced Swift-XRT position
  40. GRB 240511A: Swift detection of a burst
  41. GRB 240504A: Fermi GBM Observation
  42. IPN triangulation of GRB 240504A
  43. GRB 240502A: 1.3m DFOT Optical upper limit
  44. GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  45. GRB 240415A 1.3m DFOT Optical upper limit
  46. GRB 240502C: GOTO possible optical counterpart candidates
  47. X-ray transient EP240414a: Detection of associated supernova
  48. LIGO/Virgo S240422ed: Swift XRT observation of EP240426a
  49. GRB 240414A: NOEMA detection
  50. LVK S240422ed: Further Swift-XRT followup of three sources
  51. LIGO/Virgo/KAGRA S240422ed: Magellan Follow-up Observations of Swift/XRT candidates
  52. LIGO/Virgo/KAGRA S240422ed: 2.5m PRL Telescope follow-up of the Swift/XRT source S240422ed_X190
  53. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-FXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  54. LIGO/Virgo/KAGRA S240422ed: SRG/eROSITA archival upper limits for Swift/XRT candidates
  55. GRB 240419B: Swift-BAT refined analysis
  56. GRB 240421B: Swift-BAT refined analysis
  57. LIGO/Virgo/KAGRA S240422ed: Himalayan Chandra Telescope follow-up of the Swift/XRT source S240422ed_X101
  58. IceCube-240424A - IceCube observation of a high-energy neutrino candidate track-like event
  59. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Potential Electromagnetic Counterparts Reported by Swift and DECam
  60. LIGO/Virgo S240422ed: Swift-XRT detection of 3 possible counterparts
  61. LIGO/Virgo/KAGRA S240422ed: NOT J-band upper limit on the Swift/XRT source S240422ed_X61
  62. LIGO/Virgo/KAGRA S240422ed: X-ray Upper Limits from EP-WXT for the Three Potential Electromagnetic Counterparts Reported So Far
  63. GRB 240421B: GRBAlpha detection
  64. LIGO/Virgo/KAGRA S240422ed: WINTER J-band upper limits on the Swift/XRT source S240422ed_X61
  65. LIGO/Virgo/KAGRA S240422ed: GW-MMADS DECam upper limits on the Swift/XRT source S240422ed_X61
  66. GRB 240419A: Swift-BAT refined analysis
  67. GRB 240418A: Swift-BAT refined analysis
  68. LXT240402A/GRB240402B: Chandra X-ray detection
  69. GRB 240419A: Possible ATCA radio detection
  70. GRB 240421B: ATCA radio observations
  71. LIGO/Virgo/KAGRA S240421ar: Upper limits from Swift/BAT-GUANO
  72. GRB 240414A: AMI-LA radio observations
  73. GRB 240419B : MITSuME Akeno optical upper limits
  74. GRB 240415B: Swift-XRT observations
  75. GRB 240415A: Swift-XRT refined Analysis
  76. GRB 240421B: AstroSat CZTI detection
  77. GRB240421B: Zadko Observations
  78. Swift GRB 240421B: Global MASTER-Net observations report
  79. GRB 240421B: Fermi GBM Observation
  80. GRB 240421B: Swift-XRT refined Analysis
  81. GRB240421B: BOOTES-5/JGT optical upper limit
  82. GRB 240421B: Swift/UVOT Upper Limits
  83. GRB 240421B: Enhanced Swift-XRT position
  84. GRB 240421B: Swift detection of a burst
  85. GRB240419A: Skynet Optical Afterglow Analysis
  86. GRB240418A - Candidate afterglow from NIRES
  87. GRB 240419B: Swift/UVOT Upper Limits
  88. GRB 240419A: Swift/UVOT Upper Limits
  89. GRB 240419B: Swift-XRT refined Analysis
  90. GRB 240419B: optical afterglow from the NOT
  91. Swift GRB 240419B: Global MASTER-Net observations report
  92. GRB 240419B: Enhanced Swift-XRT position
  93. Swift GRB 240419A: Global MASTER-Net observations report
  94. GRB 240418A: Swift/UVOT Upper Limits
  95. GRB 240419A: REM NIR afterglow detection
  96. GRB 240419A: Swift-XRT refined Analysis
  97. GRB 240418A: Swift-XRT refined Analysis
  98. GRB 240419B: Swift detection of a burst
  99. GRB 240411B: Swift/UVOT Detection
  100. GRB240418A: YAHPT Upper Limits

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