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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"

37349 results found.

  1. GRB 240415B: Swift-XRT observations
  2. GRB 240415A: Swift-XRT refined Analysis
  3. Fermi GRB 240422A: Global MASTER-Net observations report
  4. GRB 240421B: AstroSat CZTI detection
  5. GRB 240422A: Fermi GBM Final Real-time Localization
  6. GRB240421B: Zadko Observations
  7. Fermi GRB 240421B: Global MASTER-Net observations report
  8. Swift GRB 240421B: Global MASTER-Net observations report
  9. GRB 240421B: Fermi GBM Observation
  10. GRB 240421B: Swift-XRT refined Analysis
  11. GRB240421B: BOOTES-5/JGT optical upper limit
  12. GRB 240421B: J-band upper limits from WINTER
  13. GRB 240421B: Swift/UVOT Upper Limits
  14. GRB 240421B: Enhanced Swift-XRT position
  15. Fermi GRB 240421A: Global MASTER-Net observations report
  16. GRB 240421B: Swift detection of a burst
  17. EP240420a: Nanshan optical counterpart observations
  18. GRB 240421A: Fermi GBM Final Real-time Localization
  19. GRB240419A: Skynet Optical Afterglow Analysis
  20. GRB240418A - Candidate afterglow from NIRES
  21. GRB 240419B: Swift/UVOT Upper Limits
  22. GRB 240419A: Swift/UVOT Upper Limits
  23. GRB 240419B: Swift-XRT refined Analysis
  24. GRB 240419B: optical afterglow from the NOT
  25. Swift GRB 240419B: Global MASTER-Net observations report
  26. EP240414A: Terskol Zeiss-2000 optical upper limit
  27. GRB 240419B: Enhanced Swift-XRT position
  28. Swift GRB 240419A: Global MASTER-Net observations report
  29. GRB 240418A: Swift/UVOT Upper Limits
  30. GRB 240419A: REM NIR afterglow detection
  31. GRB 240419A: Swift-XRT refined Analysis
  32. GRB 240418A: Swift-XRT refined Analysis
  33. GRB 240419B: Swift detection of a burst
  34. GRB 240411B: Swift/UVOT Detection
  35. GRB240418A: YAHPT Upper Limits
  36. GRB 240419A: VLT/UVES redshift of z = 5.178
  37. GRB 240419A: VLT optical afterglow detection
  38. GRB 240419A: Enhanced Swift-XRT position
  39. GRB 240419A: Prompt enhanced Swift-XRT position
  40. GRB 240419A: Swift detection of a burst
  41. GRB 240418A: TSHAO Zeiss-1000 optical upper limit
  42. GRB 240418A: NOT optical upper limits
  43. GRB 240418A: Enhanced Swift-XRT position
  44. GRB 240418A: AKO Upper Limit
  45. GRB 240411A: GOTO early optical upper limits
  46. GRB 240418A: Swift detection of a burst
  47. Fermi GRB 240417A: Global MASTER-Net observations report
  48. EP240416A: Terskol Zeiss-2000 optical upper limit
  49. EP240416A: Khureltogoot optical upper limit
  50. Improved IPN triangulation of GRB 240411A
  51. EP240416a: BOOTES-2/TELMA Optical Upper Limit
  52. LIGO/Virgo/KAGRA S240413p: DECam GW-MMADS candidates
  53. GRB 240417A: Fermi GBM Final Real-time Localization
  54. GRB 240415A: Glowbug gamma-ray detection
  55. GRB 240414A: Glowbug gamma-ray detection
  56. GRB 240415B: GECAM-B detection
  57. EP 240416a: Xinglong and NOT decaying optical counterpart
  58. GRB 240415A: Swift-BAT refined analysis
  59. GRB 240411A: Glowbug gamma-ray detection
  60. GRB 240414A: Swift-BAT refined analysis
  61. EP240416a: Kinder optical counterpart candidate
  62. GRB 240414A: AbAO optical upprer limit
  63. GRB 240415A: Swift/UVOT Detection
  64. EP240413a: BOOTES-2/TELMA Optical Upper Limit
  65. GRB 240415A: Fermi GBM Observation
  66. GRB 240414A: GAD Observatory, La Spezia, Italy ,upper limit
  67. GRB 240415A: Earliest optical followup with the Kinder observations
  68. GRB 240414A: GMG observation
  69. EP 240414a: BOOTES-4/MET Optical Upper Limits
  70. GRB 240415A: Enhanced Swift-XRT position
  71. GRB 240415B: Swift ToO observations
  72. GRB 240415B: Swift/BAT-GUANO Correction
  73. GRB 240415B: Swift/BAT-GUANO arcminute localization of a short burst
  74. GRB 240415A: OHP/T193 optical observations
  75. GRB 240415A: optical afterglow detection from the INAF Asiago Observatory
  76. GRB 240415A: SAO RAS optical observations
  77. GRB 240415A: Mondy optical transient detection (photometry correction in GCN 36118 )
  78. GRB 240414A: Fermi GBM Observation
  79. Fermi GRB 240415A: Global MASTER-Net observations report
  80. GRB 240415A: Mondy optical transient detection
  81. GRB 240414A: Photometric observation from 2.2m CAHA
  82. GRB 240414A: Swift/UVOT Detection
  83. LXT 240402A/GRB 240402B: Swift follow-up observations
  84. GRB 240414A: Mondy optical observations
  85. GRB 240414B: Fermi GBM Final Real-time Localization
  86. GRB 240414A: AKO Optical Upper Limit
  87. GRB 240415A: Prompt Swift-XRT observations
  88. GRB 240415A: Swift detection of a burst
  89. GRB 240415A: Fermi GBM Final Real-time Localization
  90. EP240413a: Upper limits from GECAM-B Observation
  91. GRB 240414A: Swift-XRT refined Analysis
  92. GRB240414A : J-band upper limits from WINTER
  93. GRB 240414A: Enhanced Swift-XRT position
  94. GRB 240414A : OHP/T193 second epoch of optical follow-up and afterglow detection
  95. GRB 240414A: MarSEC Observatory, Vicenza, Italy, UPPER LIMIT
  96. GRB 240414A: Skynet Optical Afterglow Observations
  97. Swift GRB 240414A: Global MASTER-Net observations report
  98. EP240414a: Kinder optical counterpart candidate possibly associated with the galaxy SDSS J124601.99-094309.3
  99. IPN triangulation of GRB 240410A
  100. IPN triangulation of GRB 240411A

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