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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"

3115 results found.

  1. EP240919a: EP-WXT detection of a fast X-ray transient
  2. EP240918b and EP240918c: EP-WXT detection of two fast X-ray transients
  3. EP EP240918a: Global MASTER-Net observations report
  4. GRB 240914B: AstroSat CZTI detection
  5. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  6. GRB 240914B: BALROG localization (Fermi Trigger 747990592 / GRB 240914298)
  7. GRB 240912A: SVOM/GRM observation
  8. GRB 240825A: 7DT Optical Upper Limit
  9. GRB 240902B: AstroSat CZTI detection of a long burst
  10. GRB 240825A: Montarrenti Observatory optical follow-up observations
  11. Fermi trigger No 746923430: Global MASTER-Net observations report
  12. GRB 240828B: SVOM/C-GFT optical upper limit
  13. Fermi GRB 240828A: Bassano Bresciano Observatory upper limit
  14. Fermi trigger No 746438824: Global MASTER-Net observations report
  15. GRB 240828A: Fermi GBM Final Real-time Localization
  16. Swift GRB240824.04: Global MASTER-Net observations report
  17. GRB 240822A: AstroSat CZTI detection of a short burst
  18. Fermi trigger No 746019401: Global MASTER-Net observations report
  19. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  20. Fermi trigger No 745935375: Global MASTER-Net observations report
  21. Fermi trigger No 745866488: Global MASTER-Net observations report
  22. EP240820a: EP detection of a fast X-ray transient
  23. Fermi trigger No 745871958: Global MASTER-Net observations report
  24. GRB 240817A: Fermi GBM Final Real-time Localization
  25. EP EP240816b: Global MASTER-Net observations report
  26. EP240816b: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  27. Fermi GRB 240814B: Global MASTER-Net observations report
  28. EP EP240807a: Global MASTER-Net observations report
  29. EP EP240806a: Global MASTER-Net observations report
  30. EP240806A: Liverpool Telescope optical follow-up observations
  31. Fermi trigger No 744629911: Global MASTER-Net observations report
  32. Konus-Wind detection of GRB 240802A (EP240802a)
  33. EP240806a: EP-WXT detection of a fast X-ray transient
  34. EP240801a: BTA BVRI photometry
  35. Fermi GRB 240805A: Global MASTER-Net observations report
  36. Swift GRB 240805A: Global MASTER-Net observations report
  37. GRB 240804A: Fermi GBM Final Real-time Localization
  38. Fermi trigger No 744128417: Global MASTER-Net observations report
  39. Fermi trigger No 743953682: Global MASTER-Net observations report
  40. Fermi Gamma-ray Burst Monitor trigger 743953682/240729575 is not a GRB
  41. GRB 240726A: Fermi GBM Final Real-time Localization
  42. IceCube-240721A: Two candidates from the Zwicky Transient Facility
  43. Fermi trigger No 743418632: Global MASTER-Net observations report
  44. Fermi trigger No 743219692: Global MASTER-Net observations report
  45. IceCube Alert 240721.68: Global MASTER-Net observations report
  46. Fermi GRB 240720A: Global MASTER-Net observations report
  47. GRB 240720A: Fermi GBM observation
  48. Fermi GRB 240718A: Global MASTER-Net observations report
  49. Konus-Wind detection of GRB 240715A
  50. GRB 240715A: Fermi GBM Observation
  51. GRB 240713B: AstroSat CZTI detection of a long burst
  52. GRB 240712A: Swift detection of a burst
  53. Fermi trigger No 742317942: Global MASTER-Net observations report
  54. GRB 240710A: Fermi GBM Final Real-time Localization
  55. EP240708a: X-ray follow-up observations with EP/FXT and Swift/XRT
  56. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  57. GRB 240627A: AstroSat CZTI detection
  58. Fermi trigger No 741211696: Global MASTER-Net observations report
  59. GRB 240619B: Fermi GBM Final Real-time Localization
  60. Fermi trigger No 740430582: Global MASTER-Net observations report
  61. Fermi GRB 240616A: Global MASTER-Net observations report
  62. Fermi trigger No 740166710: Global MASTER-Net observations report
  63. Fermi GRB 240610A: Global MASTER-Net observations report
  64. Fermi GRB 240607A: Global MASTER-Net observations report
  65. GRB 240529A: SAO RAS optical observations
  66. Fermi GRB 240603C: Global MASTER-Net observations report
  67. GRB 240603C: Fermi GBM Final Real-time Localization
  68. GRB 240529A: continued SAO RAS optical observations
  69. Fermi GRB 240602A: Global MASTER-Net observations report
  70. GRB 240529A: J-band detections with WINTER
  71. GRB 240529A: NOT optical observations
  72. GRB 240523A: Swift-BAT refined analysis
  73. Fermi trigger No 738348224: Global MASTER-Net observations report
  74. GRB 240523A: Swift detection of a burst
  75. Fermi trigger No 737996942: Global MASTER-Net observations report
  76. Fermi GRB 240517A: Global MASTER-Net observations report
  77. GRB 240516A: Fermi GBM Observation
  78. Fermi trigger No 737523389: Global MASTER-Net observations report
  79. MAXI GRB240514.78: Global MASTER-Net observations report
  80. LIGO/Virgo/KAGRA S240514c: Identification of a GW compact binary merger candidate
  81. Fermi Gamma-ray Burst Monitor triggers 737345659/240514093 and GRB240514A are not GRBs
  82. GRB 240514A: Fermi GBM Final Real-time Localization
  83. LAT GRB240513.31: Global MASTER-Net observations report
  84. Fermi GRB 240513B: Global MASTER-Net observations report
  85. GRB 240513B: Fermi GBM Final Real-time Localization
  86. Fermi trigger No 737247400: Global MASTER-Net observations report
  87. Fermi trigger No 737196587: Global MASTER-Net observations report
  88. Fermi trigger No 737168073: Global MASTER-Net observations report
  89. Fermi trigger No 737105243: Global MASTER-Net observations report
  90. GRB 240511A: Fermi GBM Final Real-time Localization
  91. Fermi trigger No 737111207: Global MASTER-Net observations report
  92. IPN triangulation of GRB 240504A
  93. Fermi trigger No 736564880: Global MASTER-Net observations report
  94. GRB 240503A: AstroSat CZTI detection
  95. Fermi trigger No 736387941: Global MASTER-Net observations report
  96. Fermi GRB 240501A: Global MASTER-Net observations report
  97. Fermi trigger No 736197684: Global MASTER-Net observations report
  98. GRB 240501B: AstroSat CZTI detection
  99. GRB 240426A: AstroSat CZTI detection
  100. EP240426a: YAHPT optical upper limit

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