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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"

39263 results found.

  1. LIGO/Virgo/KAGRA S240422ed: Upper limits from Fermi-GBM Observations
  2. LIGO/Virgo/KAGRA S240421ar: Upper limits from Swift/BAT-GUANO
  3. LIGO/Virgo/KAGRA S240422ed: MeerLICHT and BlackGEM observations report
  4. LIGO/Virgo/Kagra S240422ed: NED Galaxies in the Localization Volume
  5. LIGO/Virgo/KAGRA S240422ed: Global MASTER-Net observations report
  6. Fermi trigger No 735470374: Global MASTER-Net observations report
  7. GRB 240421A: Glowbug gamma-ray detection
  8. GRB 240414A: radio detection with the VLA
  9. Fermi-LAT gamma-ray observations of IceCube-240419A
  10. GRB 240414A: AMI-LA radio observations
  11. GRB 240414A: LBT optical detection
  12. GRB 240419B : MITSuME Akeno optical upper limits
  13. GRB 240415B: Swift-XRT observations
  14. GRB 240415A: Swift-XRT refined Analysis
  15. Fermi GRB 240422A: Global MASTER-Net observations report
  16. GRB 240421B: AstroSat CZTI detection
  17. GRB 240422A: Fermi GBM Final Real-time Localization
  18. GRB240421B: Zadko Observations
  19. Fermi GRB 240421B: Global MASTER-Net observations report
  20. Swift GRB 240421B: Global MASTER-Net observations report
  21. GRB 240421B: Fermi GBM Observation
  22. GRB 240421B: Swift-XRT refined Analysis
  23. GRB240421B: BOOTES-5/JGT optical upper limit
  24. GRB 240421B: J-band upper limits from WINTER
  25. GRB 240421B: Swift/UVOT Upper Limits
  26. GRB 240421B: Enhanced Swift-XRT position
  27. Fermi GRB 240421A: Global MASTER-Net observations report
  28. EP240420a: TNT upper limit to its optical counterpart
  29. EP240420a: Xinglong decaying optical counterpart
  30. GRB 240421B: Swift detection of a burst
  31. EP240420a: Nanshan optical counterpart observations
  32. GRB 240421A: Fermi GBM Final Real-time Localization
  33. Fermi trigger No 735280430: Global MASTER-Net observations report
  34. GRB240419A: Skynet Optical Afterglow Analysis
  35. GRB240418A - Candidate afterglow from NIRES
  36. IceCube Alert 240419.98: Global MASTER-Net observations report
  37. GRB 240419B: Swift/UVOT Upper Limits
  38. IceCube-240419A - IceCube observation of a high-energy neutrino candidate track-like event
  39. IceCube-240419A - IceCube observation of a high-energy neutrino candidate track-like event
  40. GRB 240419A: Swift/UVOT Upper Limits
  41. GRB 240419B: Swift-XRT refined Analysis
  42. GRB 240419B: optical afterglow from the NOT
  43. Swift GRB 240419B: Global MASTER-Net observations report
  44. EP240414A: Terskol Zeiss-2000 optical upper limit
  45. GRB 240419B: Enhanced Swift-XRT position
  46. Swift GRB 240419A: Global MASTER-Net observations report
  47. GRB 240418A: Swift/UVOT Upper Limits
  48. GRB 240419A: REM NIR afterglow detection
  49. GRB 240419A: Swift-XRT refined Analysis
  50. GRB 240418A: Swift-XRT refined Analysis
  51. GRB 240419B: Swift detection of a burst
  52. GRB 240411B: Swift/UVOT Detection
  53. GRB240418A: YAHPT Upper Limits
  54. GRB 240419A: VLT/UVES redshift of z = 5.178
  55. GRB 240419A: VLT optical afterglow detection
  56. GRB 240419A: Enhanced Swift-XRT position
  57. Fermi trigger No 735089036: Global MASTER-Net observations report
  58. GRB 240419A: Prompt enhanced Swift-XRT position
  59. GRB 240419A: Swift detection of a burst
  60. GRB 240418A: TSHAO Zeiss-1000 optical upper limit
  61. GRB 240418A: NOT optical upper limits
  62. GRB 240418A: Enhanced Swift-XRT position
  63. GRB 240418A: AKO Upper Limit
  64. GRB 240411A: GOTO early optical upper limits
  65. Swift GRB240418.85: Global MASTER-Net observations report
  66. GRB 240418A: Swift detection of a burst
  67. Fermi GRB 240417A: Global MASTER-Net observations report
  68. EP240416A: Terskol Zeiss-2000 optical upper limit
  69. EP240416A: Khureltogoot optical upper limit
  70. Improved IPN triangulation of GRB 240411A
  71. EP240414a: GSP detects optical candidate counterpart AT2024gsa
  72. GRB 240417A: Fermi GBM Final Real-time Localization
  73. GRB 240415A: Glowbug gamma-ray detection
  74. GRB 240414A: Glowbug gamma-ray detection
  75. GRB 240415B: GECAM-B detection
  76. EP 240416a: Xinglong and NOT decaying optical counterpart
  77. GRB 240415A: Swift-BAT refined analysis
  78. EP240416A: MASTER optical observations
  79. GRB 240411A: Glowbug gamma-ray detection
  80. GRB 240414A: Swift-BAT refined analysis
  81. GRB 240414A: AbAO optical upprer limit
  82. GRB 240415A: Swift/UVOT Detection
  83. GRB 240415A: Fermi GBM Observation
  84. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  85. GRB 240415A: Earliest optical followup with the Kinder observations
  86. GRB 240414A: GMG observation
  87. EP 240414a: BOOTES-4/MET Optical Upper Limits
  88. GRB 240415A: Enhanced Swift-XRT position
  89. GRB 240415B: Swift ToO observations
  90. GRB 240415B: Swift/BAT-GUANO Correction
  91. GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
  92. GRB 240415A: OHP/T193 optical observations
  93. GRB 240415A: optical afterglow detection from the INAF Asiago Observatory
  94. GRB 240415A: SAO RAS optical observations
  95. GRB 240415A: Mondy optical transient detection (photometry correction in GCN 36118 )
  96. GRB 240414A: Fermi GBM Observation
  97. Fermi GRB 240415A: Global MASTER-Net observations report
  98. GRB 240415A: Mondy optical transient detection
  99. GRB 240414A: Photometric observation from 2.2m CAHA
  100. GRB 240414A: Swift/UVOT Detection

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Download all Circulars as a .tar.gz archive (updated once a day):
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