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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"

36397 results found.

  1. GRB 240421B: GRBAlpha detection
  2. IceCube-240419A: Upper limits from a search for additional neutrino events in IceCube
  3. GRB 240419A: Swift-BAT refined analysis
  4. GRB 240418A: Swift-BAT refined analysis
  5. LXT240402A/GRB240402B: Chandra X-ray detection
  6. GRB 240419A: Possible ATCA radio detection
  7. GRB 240421B: ATCA radio observations
  8. LIGO/Virgo S240422ed: No counterpart candidates in INTEGRAL SPI-ACS prompt observation
  9. LIGO/Virgo/KAGRA S240422ed: AstroSat CZTI non-detection and upper limits
  10. LIGO/Virgo/KAGRA S240422ed: Upper limits from Fermi-GBM Observations
  11. LIGO/Virgo/KAGRA S240421ar: Upper limits from Swift/BAT-GUANO
  12. GRB 240421A: Glowbug gamma-ray detection
  13. GRB 240414A: radio detection with the VLA
  14. GRB 240414A: AMI-LA radio observations
  15. GRB 240414A: LBT optical detection
  16. GRB 240419B : MITSuME Akeno optical upper limits
  17. GRB 240415B: Swift-XRT observations
  18. GRB 240415A: Swift-XRT refined Analysis
  19. Fermi GRB 240422A: Global MASTER-Net observations report
  20. GRB 240421B: AstroSat CZTI detection
  21. GRB 240422A: Fermi GBM Final Real-time Localization
  22. GRB240421B: Zadko Observations
  23. Fermi GRB 240421B: Global MASTER-Net observations report
  24. Swift GRB 240421B: Global MASTER-Net observations report
  25. GRB 240421B: Fermi GBM Observation
  26. GRB 240421B: Swift-XRT refined Analysis
  27. GRB240421B: BOOTES-5/JGT optical upper limit
  28. GRB 240421B: J-band upper limits from WINTER
  29. GRB 240421B: Swift/UVOT Upper Limits
  30. GRB 240421B: Enhanced Swift-XRT position
  31. Fermi GRB 240421A: Global MASTER-Net observations report
  32. GRB 240421B: Swift detection of a burst
  33. EP240420a: Nanshan optical counterpart observations
  34. GRB 240421A: Fermi GBM Final Real-time Localization
  35. GRB240419A: Skynet Optical Afterglow Analysis
  36. GRB240418A - Candidate afterglow from NIRES
  37. GRB 240419B: Swift/UVOT Upper Limits
  38. GRB 240419A: Swift/UVOT Upper Limits
  39. GRB 240419B: Swift-XRT refined Analysis
  40. GRB 240419B: optical afterglow from the NOT
  41. Swift GRB 240419B: Global MASTER-Net observations report
  42. EP240414A: Terskol Zeiss-2000 optical upper limit
  43. GRB 240419B: Enhanced Swift-XRT position
  44. Swift GRB 240419A: Global MASTER-Net observations report
  45. GRB 240418A: Swift/UVOT Upper Limits
  46. GRB 240419A: REM NIR afterglow detection
  47. GRB 240419A: Swift-XRT refined Analysis
  48. GRB 240418A: Swift-XRT refined Analysis
  49. GRB 240419B: Swift detection of a burst
  50. GRB 240411B: Swift/UVOT Detection
  51. GRB240418A: YAHPT Upper Limits
  52. GRB 240419A: VLT/UVES redshift of z = 5.178
  53. GRB 240419A: VLT optical afterglow detection
  54. GRB 240419A: Enhanced Swift-XRT position
  55. GRB 240419A: Prompt enhanced Swift-XRT position
  56. GRB 240419A: Swift detection of a burst
  57. GRB 240418A: TSHAO Zeiss-1000 optical upper limit
  58. GRB 240418A: NOT optical upper limits
  59. GRB 240418A: Enhanced Swift-XRT position
  60. GRB 240418A: AKO Upper Limit
  61. GRB 240411A: GOTO early optical upper limits
  62. GRB 240418A: Swift detection of a burst
  63. Fermi GRB 240417A: Global MASTER-Net observations report
  64. EP240416A: Terskol Zeiss-2000 optical upper limit
  65. EP240416A: Khureltogoot optical upper limit
  66. Improved IPN triangulation of GRB 240411A
  67. GRB 240417A: Fermi GBM Final Real-time Localization
  68. GRB 240415A: Glowbug gamma-ray detection
  69. GRB 240414A: Glowbug gamma-ray detection
  70. GRB 240415B: GECAM-B detection
  71. EP 240416a: Xinglong and NOT decaying optical counterpart
  72. GRB 240415A: Swift-BAT refined analysis
  73. GRB 240411A: Glowbug gamma-ray detection
  74. GRB 240414A: Swift-BAT refined analysis
  75. GRB 240414A: AbAO optical upprer limit
  76. GRB 240415A: Swift/UVOT Detection
  77. GRB 240415A: Fermi GBM Observation
  78. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  79. GRB 240415A: Earliest optical followup with the Kinder observations
  80. GRB 240414A: GMG observation
  81. GRB 240415A: Enhanced Swift-XRT position
  82. GRB 240415B: Swift ToO observations
  83. GRB 240415B: Swift/BAT-GUANO Correction
  84. GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
  85. GRB 240415A: OHP/T193 optical observations
  86. GRB 240415A: optical afterglow detection from the INAF Asiago Observatory
  87. GRB 240415A: SAO RAS optical observations
  88. GRB 240415A: Mondy optical transient detection (photometry correction in GCN 36118 )
  89. GRB 240414A: Fermi GBM Observation
  90. Fermi GRB 240415A: Global MASTER-Net observations report
  91. GRB 240415A: Mondy optical transient detection
  92. GRB 240414A: Photometric observation from 2.2m CAHA
  93. IceCube-240412A: Upper limits from a search for additional neutrino events in IceCube
  94. GRB 240414A: Swift/UVOT Detection
  95. LXT 240402A/GRB 240402B: Swift follow-up observations
  96. GRB 240414A: Mondy optical observations
  97. GRB 240414B: Fermi GBM Final Real-time Localization
  98. GRB 240414A: AKO Optical Upper Limit
  99. GRB 240415A: Prompt Swift-XRT observations
  100. GRB 240415A: Swift detection of a burst

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