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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"

28261 results found.

  1. Swift Trigger 1235109: consistent with noise and not astrophysical
  2. GRB 240607A: Fermi GBM detection of a very bright burst
  3. GRB 240529A: radio detection with AMI-LA
  4. GRB 240607A: BALROG localization (Fermi Trigger 739450879 / GRB 240607459)
  5. GRB 240606B: Swift-XRT afterglow detection
  6. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  7. Swift Trigger 1235109: a possible GRB 240606A
  8. LIGO/Virgo/KAGRA S240601co: Updated Sky localization
  9. GRB 240604A: GECAM detection of a long burst
  10. GRB 240529A: SAO RAS optical observations
  11. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  12. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  13. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  14. GRB 240603C: BALROG localization (Fermi Trigger 739102156 / GRB 240603423)
  15. Swift Trigger 1232465: consistent with noise
  16. GRB 240529A: MASTER prompt OT detection
  17. GRB 240603A: GECAM detection of a short burst
  18. GRB 240529A: continued SAO RAS optical observations
  19. GRB 240529A: OSN optical detection
  20. The EP-WXT source triggered on June 1st is likely a flaring star
  21. GRB 240529A: further SAO RAS optical observations
  22. LIGO/Virgo/KAGRA S240601aj: Updated Sky localization
  23. LIGO/Virgo/KAGRA S240601co: Identification of a GW compact binary merger candidate
  24. Swift Trigger 1232465 is not a GRB
  25. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  26. LIGO/Virgo/KAGRA S240530a: Updated Sky localization
  27. LXT 240528A: GSP optical upper limit
  28. GRB 240529A: 1.3m DFOT Optical observations
  29. LIGO/Virgo/KAGRA S240527en: Updated Sky localization
  30. LIGO/Virgo/KAGRA S240601aj: Identification of a GW compact binary merger candidate
  31. GRB 240531A: AstroSat CZTI detection of a short burst
  32. GRB 240529A : Mondy optical observations
  33. GRB 240529A: SAO RAS optical observations
  34. LIGO/Virgo/KAGRA S240531bp: Updated Sky localization
  35. LIGO/Virgo/KAGRA S240531bp: Identification of a GW compact binary merger candidate
  36. GRB 240529A: GROWTH-India optical follow-up
  37. GRB 240529A: T193/MISTRAL observations
  38. GRB 240529A: Redshift from GTC/OSIRIS+
  39. GRB 240529A: AKO Optical Afterglow Detection
  40. LIGO/Virgo/KAGRA S240530a: Identification of a GW compact binary merger candidate
  41. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  42. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  43. GRB 240529A: J-band detections with WINTER
  44. GRB 240529A: Skynet Optical Observations
  45. LXT 240528A: LEIA detection of a fast X-ray transient
  46. GRB 240529A: Swift-BAT refined analysis
  47. LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
  48. GRB 240529A: Swift-XRT refined Analysis
  49. GRB 240529A: Swift/UVOT Detection
  50. GRB 240529A: NOT optical observations
  51. GRB 240527B: Swift-XRT afterglow detection
  52. GRB 240529A: Enhanced Swift-XRT position
  53. GRB 240529A: Swift detection of a burst with an optical counterpart
  54. LIGO/Virgo/KAGRA S240527fv: Updated Sky localization
  55. GRB 240527B: Fermi GBM Observation
  56. LIGO/Virgo/KAGRA S240527fv: Identification of a GW compact binary merger candidate
  57. LIGO/Virgo/KAGRA S240527en: Identification of a GW compact binary merger candidate
  58. GRB 240527B: BALROG localization (Fermi Trigger 738511436 / GRB 240527586)
  59. GRB 240523A: Swift-BAT refined analysis
  60. LIGO/Virgo/KAGRA S240525p: Updated Sky localization
  61. LIGO/Virgo/KAGRA S240525p: Identification of a GW compact binary merger candidate
  62. GRB 240523A: Swift-XRT refined Analysis
  63. GRB 240523A: Enhanced Swift-XRT position
  64. GRB 240523A: Swift detection of a burst
  65. GRB 240521B: Fermi GBM Observation
  66. Fermi GBM Sub-Threshold Detection of GRB 240516B
  67. GRB 240521B: Swift/BAT-GUANO arcminute localization of a long burst
  68. LIGO/Virgo/KAGRA S240520cv: Updated Sky localization and EM Bright Classification
  69. EP240518a: GSP optical upper limit
  70. GRB 240521A: GECAM-B detection of a long burst
  71. GRB 240516B: AstroSat CZTI detection
  72. LIGO/Virgo/KAGRA S240515m: Upper limits from Swift/BAT-GUANO
  73. LIGO/Virgo/KAGRA S240514x: Upper limits from Swift/BAT-GUANO
  74. LIGO/Virgo/KAGRA S240513ei: Upper limits from Swift/BAT-GUANO
  75. LIGO/Virgo/KAGRA S240520cv: Identification of a GW compact binary merger candidate
  76. IceCube-Cascade 240518A: Upper limits from a search for additional neutrino events in IceCube
  77. GRB 240514B: VZLUSAT-2 detection
  78. GRB 240504A: VZLUSAT-2 detection
  79. GRB 240502A: VZLUSAT-2 detection
  80. GRB 240516A: Swift/UVOT Upper Limits
  81. EP240518a: possibly identified with a flare star by EP-FXT
  82. GRB 240519A: BALROG localization (Fermi Trigger 737788024 / GRB 240519213)
  83. EP240518a: EP-WXT detection of a new X-ray transient
  84. LIGO/Virgo/KAGRA S240514c: Updated Sky localization
  85. GRB 240516A: Swift-BAT refined analysis
  86. IPN triangulation of GRB 240514B (short)
  87. GRB 240516A: Swift-XRT refined Analysis
  88. GRB 240516A: Fermi GBM Observation
  89. GRB 240511A: Observations from GTC/OSIRIS+
  90. GRB 240516A: Swift detection of a burst
  91. GRB 240511A: radio detection of afterglow candidate
  92. MAXI GRB240514.78: Global MASTER-Net observations report
  93. GRB 240514E: MAXI/GSC detection of a probable afterglow
  94. LIGO/Virgo/KAGRA S240514x: Updated Sky localization
  95. LIGO/Virgo/KAGRA S240515m: Identification of a GW compact binary merger candidate
  96. GRB 240513A: Fermi GBM observation
  97. GRB 240513A: Swift-XRT observations
  98. LIGO/Virgo/KAGRA S240513ei: Updated Sky localization
  99. LIGO/Virgo/KAGRA S240514x: Identification of a GW compact binary merger candidate
  100. LIGO/Virgo/KAGRA S240514c: Identification of a GW compact binary merger candidate

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