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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"

3106 results found.

  1. EP240918b and EP240918c: EP-WXT detection of two fast X-ray transients
  2. EP EP240918a: Global MASTER-Net observations report
  3. GRB 240914B: AstroSat CZTI detection
  4. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  5. GRB 240914B: BALROG localization (Fermi Trigger 747990592 / GRB 240914298)
  6. GRB 240912A: SVOM/GRM observation
  7. GRB 240825A: 7DT Optical Upper Limit
  8. GRB 240902B: AstroSat CZTI detection of a long burst
  9. GRB 240825A: Montarrenti Observatory optical follow-up observations
  10. Fermi trigger No 746923430: Global MASTER-Net observations report
  11. GRB 240828B: SVOM/C-GFT optical upper limit
  12. Fermi GRB 240828A: Bassano Bresciano Observatory upper limit
  13. Fermi trigger No 746438824: Global MASTER-Net observations report
  14. GRB 240828A: Fermi GBM Final Real-time Localization
  15. Swift GRB240824.04: Global MASTER-Net observations report
  16. GRB 240822A: AstroSat CZTI detection of a short burst
  17. Fermi trigger No 746019401: Global MASTER-Net observations report
  18. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  19. Fermi trigger No 745935375: Global MASTER-Net observations report
  20. Fermi trigger No 745866488: Global MASTER-Net observations report
  21. EP240820a: EP detection of a fast X-ray transient
  22. GRB 240817A: Fermi GBM Final Real-time Localization
  23. EP EP240816b: Global MASTER-Net observations report
  24. EP240816b: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  25. Fermi GRB 240814B: Global MASTER-Net observations report
  26. EP EP240807a: Global MASTER-Net observations report
  27. EP EP240806a: Global MASTER-Net observations report
  28. EP240806A: Liverpool Telescope optical follow-up observations
  29. Fermi trigger No 744629911: Global MASTER-Net observations report
  30. Konus-Wind detection of GRB 240802A (EP240802a)
  31. EP240806a: EP-WXT detection of a fast X-ray transient
  32. EP240801a: BTA BVRI photometry
  33. Fermi GRB 240805A: Global MASTER-Net observations report
  34. Swift GRB 240805A: Global MASTER-Net observations report
  35. GRB 240804A: Fermi GBM Final Real-time Localization
  36. Fermi trigger No 744128417: Global MASTER-Net observations report
  37. Fermi trigger No 743953682: Global MASTER-Net observations report
  38. Fermi Gamma-ray Burst Monitor trigger 743953682/240729575 is not a GRB
  39. GRB 240726A: Fermi GBM Final Real-time Localization
  40. IceCube-240721A: Two candidates from the Zwicky Transient Facility
  41. Fermi trigger No 743418632: Global MASTER-Net observations report
  42. Fermi trigger No 743219692: Global MASTER-Net observations report
  43. IceCube Alert 240721.68: Global MASTER-Net observations report
  44. Fermi GRB 240720A: Global MASTER-Net observations report
  45. GRB 240720A: Fermi GBM observation
  46. Fermi GRB 240718A: Global MASTER-Net observations report
  47. Konus-Wind detection of GRB 240715A
  48. GRB 240715A: Fermi GBM Observation
  49. GRB 240712A: Swift detection of a burst
  50. Fermi trigger No 742317942: Global MASTER-Net observations report
  51. GRB 240710A: Fermi GBM Final Real-time Localization
  52. EP240708a: X-ray follow-up observations with EP/FXT and Swift/XRT
  53. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  54. GRB 240627A: AstroSat CZTI detection
  55. Fermi trigger No 741211696: Global MASTER-Net observations report
  56. GRB 240619B: Fermi GBM Final Real-time Localization
  57. Fermi trigger No 740430582: Global MASTER-Net observations report
  58. Fermi GRB 240616A: Global MASTER-Net observations report
  59. Fermi trigger No 740166710: Global MASTER-Net observations report
  60. Fermi GRB 240610A: Global MASTER-Net observations report
  61. Fermi GRB 240607A: Global MASTER-Net observations report
  62. GRB 240529A: SAO RAS optical observations
  63. Fermi GRB 240603C: Global MASTER-Net observations report
  64. GRB 240603C: Fermi GBM Final Real-time Localization
  65. GRB 240529A: continued SAO RAS optical observations
  66. Fermi GRB 240602A: Global MASTER-Net observations report
  67. GRB 240529A: J-band detections with WINTER
  68. GRB 240529A: NOT optical observations
  69. GRB 240523A: Swift-BAT refined analysis
  70. Fermi trigger No 738348224: Global MASTER-Net observations report
  71. GRB 240523A: Swift detection of a burst
  72. Fermi trigger No 737996942: Global MASTER-Net observations report
  73. Fermi GRB 240517A: Global MASTER-Net observations report
  74. GRB 240516A: Fermi GBM Observation
  75. Fermi trigger No 737523389: Global MASTER-Net observations report
  76. MAXI GRB240514.78: Global MASTER-Net observations report
  77. LIGO/Virgo/KAGRA S240514c: Identification of a GW compact binary merger candidate
  78. Fermi Gamma-ray Burst Monitor triggers 737345659/240514093 and GRB240514A are not GRBs
  79. GRB 240514A: Fermi GBM Final Real-time Localization
  80. LAT GRB240513.31: Global MASTER-Net observations report
  81. Fermi GRB 240513B: Global MASTER-Net observations report
  82. GRB 240513B: Fermi GBM Final Real-time Localization
  83. Fermi trigger No 737247400: Global MASTER-Net observations report
  84. Fermi trigger No 737196587: Global MASTER-Net observations report
  85. Fermi trigger No 737168073: Global MASTER-Net observations report
  86. Fermi trigger No 737105243: Global MASTER-Net observations report
  87. GRB 240511A: Fermi GBM Final Real-time Localization
  88. Fermi trigger No 737111207: Global MASTER-Net observations report
  89. IPN triangulation of GRB 240504A
  90. Fermi trigger No 736564880: Global MASTER-Net observations report
  91. GRB 240503A: AstroSat CZTI detection
  92. Fermi trigger No 736387941: Global MASTER-Net observations report
  93. Fermi GRB 240501A: Global MASTER-Net observations report
  94. Fermi trigger No 736197684: Global MASTER-Net observations report
  95. GRB 240501B: AstroSat CZTI detection
  96. GRB 240426A: AstroSat CZTI detection
  97. EP240426a: YAHPT optical upper limit
  98. LIGO/Virgo/KAGRA S240422ed: Continued Magellan Observations
  99. LIGO/Virgo/KAGRA S240422ed: Zwicky Transient Facility contuinued observations of S240422ed and candidate analysis
  100. LIGO/Virgo/KAGRA S240422ed: Further near-infrared observations with Subaru/MOIRCS by J-GEM Collaboration

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