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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

44417 results found.

  1. IPN triangulation of GRB 240607A
  2. Fermi Gamma-ray Burst Monitor trigger 739632045/240609556 is not a GRB
  3. Fermi trigger No 739632045: Global MASTER-Net observations report
  4. Fermi GRB 240608A: Global MASTER-Net observations report
  5. Konus-Wind detection of GRB 240606B
  6. Fermi trigger No 739506569: Global MASTER-Net observations report
  7. GRB 240608A: Fermi GBM Final Real-time Localization
  8. Fermi GRB 240607A: Global MASTER-Net observations report
  9. GRB 240529A: NOEMA detection
  10. GRB 240607A: Fermi GBM Observation
  11. GRB 240606B: Fermi GBM Observation
  12. Swift Trigger 1235109: consistent with noise and not astrophysical
  13. GRB 240607A: AstroSat CZTI detection of bright long burst
  14. GRB 240607A: Fermi GBM detection of a very bright burst
  15. GRB 240529A: radio detection with AMI-LA
  16. GRB 240607A: BALROG localization (Fermi Trigger 739450879 / GRB 240607459)
  17. GRB 240607A: Fermi GBM Final Real-time Localization
  18. GRB 240606B: GECAM-B detection a long burst
  19. Fermi trigger No 739373591: Global MASTER-Net observations report
  20. GRB 240606B: Swift-XRT afterglow detection
  21. Swift GRB240606.15: Global MASTER-Net observations report
  22. GRB 240606B: Swift ToO observations
  23. GRB 240606B: Swift/BAT-GUANO arcminute localization of a burst
  24. Konus-Wind detection of GRB 240603A
  25. Swift Trigger 1235109: a possible GRB 240606A
  26. Fermi GRB 240604A: Global MASTER-Net observations report
  27. IPN triangulation of GRB 240531A (short)
  28. Fermi GRB 240605A: Global MASTER-Net observations report
  29. Fermi GRB 240605C: Global MASTER-Net observations report
  30. Fermi Gamma-ray Burst Monitor trigger 739290883/240605607 is not a GRB
  31. LIGO/Virgo/KAGRA S240601co: Updated Sky localization
  32. GRB 240605C: Fermi GBM Final Real-time Localization
  33. IPN triangulation of GRB 240603A
  34. GRB 240605B: Fermi GBM Final Real-time Localization
  35. GRB 240604A: Fermi GBM Final Localization
  36. GRB 240605A: Fermi GBM Final Real-time Localization
  37. GRB 240604A: GECAM detection of a long burst
  38. GRB 240529A: SAO RAS optical observations
  39. Swift Trigger 1232755: likely consistent with noise and not astrophysical
  40. Fermi GRB 240603C: Global MASTER-Net observations report
  41. LIGO/Virgo/KAGRA S240601co: Upper limits from Swift/BAT-GUANO
  42. LIGO/Virgo/KAGRA S240530a: Upper limits from Swift/BAT-GUANO
  43. GRB 240603A: Fermi GBM Final Localization
  44. GRB 240603C: BALROG localization (Fermi Trigger 739102156 / GRB 240603423)
  45. GRB 240603C: Fermi GBM Final Real-time Localization
  46. Swift Trigger 1232465: consistent with noise
  47. GRB 240603B: Swift detection of a possible burst
  48. GRB 240529A: MASTER prompt OT detection
  49. GRB 240603A: GECAM detection of a short burst
  50. GRB 240529A: continued SAO RAS optical observations
  51. Fermi GRB 240602A: Global MASTER-Net observations report
  52. GRB 240529A: OSN optical detection
  53. The EP-WXT source triggered on June 1st is likely a flaring star
  54. GRB 240529A: further SAO RAS optical observations
  55. LIGO/Virgo/KAGRA S240601aj: Updated Sky localization
  56. GRB 240602A: Fermi GBM Final Real-time Localization
  57. LIGO/Virgo/KAGRA S240601co: Identification of a GW compact binary merger candidate
  58. Swift Trigger 1232465 is not a GRB
  59. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  60. LIGO/Virgo/KAGRA S240530a: Updated Sky localization
  61. LXT 240528A: GSP optical upper limit
  62. GRB 240529A: 1.3m DFOT Optical observations
  63. LIGO/Virgo/KAGRA S240527en: Updated Sky localization
  64. LIGO/Virgo/KAGRA S240601aj: Identification of a GW compact binary merger candidate
  65. GRB 240531A: AstroSat CZTI detection of a short burst
  66. GRB 240529A : Mondy optical observations
  67. Konus-Wind detection of GRB 240529A
  68. IPN triangulation of the initial episode of GRB 240529A
  69. GRB 240529A: SAO RAS optical observations
  70. LIGO/Virgo/KAGRA S240531bp: Updated Sky localization
  71. LIGO/Virgo/KAGRA S240531bp: Identification of a GW compact binary merger candidate
  72. GRB 240529A: MAAO 0.7m telescope optical afterglow detection
  73. GRB 240529A: Insight-HXMT/HE detection
  74. GRB 240529A: optical photometry from Konkoly
  75. GRB 240529A: GROWTH-India optical follow-up
  76. GRB 240529A: T193/MISTRAL observations
  77. GRB 240529A: Redshift from GTC/OSIRIS+
  78. GRB 240529A: AKO Optical Afterglow Detection
  79. LIGO/Virgo/KAGRA S240530a: Identification of a GW compact binary merger candidate
  80. LIGO/Virgo/KAGRA S240527fv: Upper limits from Swift/BAT-GUANO
  81. LIGO/Virgo/KAGRA S240525p: Upper limits from Swift/BAT-GUANO
  82. GRB 240529A: J-band detections with WINTER
  83. GRB 240529A: Skynet Optical Observations
  84. LXT 240528A: LEIA detection of a fast X-ray transient
  85. GRB 240529A: Swift-BAT refined analysis
  86. LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
  87. GRB 240529A: Swift-XRT refined Analysis
  88. GRB240529A: BOOTES-6/DPRT optical detection
  89. GRB 240529A: Swift/UVOT Detection
  90. GRB 240529A: NOT optical observations
  91. GRB 240529A: AstroSat CZTI detection
  92. GRB 240529A: GOTO optical afterglow detection
  93. GRB 240527B: Swift-XRT afterglow detection
  94. GRB 240529A: Enhanced Swift-XRT position
  95. GRB 240529A: Swift detection of a burst with an optical counterpart
  96. Swift GRB240529.12: Global MASTER-Net observations report
  97. LIGO/Virgo/KAGRA S240527fv: Updated Sky localization
  98. GRB 240527B: Fermi GBM Observation
  99. Fermi GRB 240527A: Global MASTER-Net observations report
  100. LIGO/Virgo/KAGRA S240527fv: Identification of a GW compact binary merger candidate

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