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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"

45767 results found.

  1. Fermi trigger No 737559855: Global MASTER-Net observations report
  2. GRB 240516A: Fermi GBM Observation
  3. GRB 240511A: Observations from GTC/OSIRIS+
  4. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  5. GRB 240516A: GOTO optical upper limit
  6. LIGO/Virgo/KAGRA S240422ed: GRID non-detection and upper limits
  7. Fermi trigger No 737523389: Global MASTER-Net observations report
  8. GRB 240516A: Swift detection of a burst
  9. Swift GRB240516.15: Global MASTER-Net observations report
  10. GRB 240514B: AT2024ixa/GOTO24bph is not consistent with the Fermi localisation
  11. Fermi trigger No 737476171: Global MASTER-Net observations report
  12. GRB 240511A: radio detection of afterglow candidate
  13. GRB 240514B: GOTO candidate optical counterpart
  14. MAXI GRB240514.78: Global MASTER-Net observations report
  15. Fermi Gamma-ray Burst Monitor list of triggers that are not a GRB
  16. GRB 240514E: MAXI/GSC detection of a probable afterglow
  17. GRB 240514B: GRBAlpha detection
  18. LIGO/Virgo/KAGRA S240514x: Updated Sky localization
  19. LIGO/Virgo/KAGRA S240515m: Identification of a GW compact binary merger candidate
  20. GRB 240514B: Fermi GBM Detection
  21. LIGO/Virgo/KAGRA S240422ed: Las Cumbres Observatory Follow-up Observations of the Localization Region
  22. GRB 240513A: Fermi GBM observation
  23. GRB 240513A: Swift-XRT observations
  24. LIGO/Virgo/KAGRA S240513ei: Updated Sky localization
  25. LIGO/Virgo/KAGRA S240514x: Identification of a GW compact binary merger candidate
  26. GRB 240514D: AstroSat CZTI detection
  27. GRB 240514C: Fermi GBM Final Real-time Localization
  28. LIGO/Virgo/KAGRA S240514c: Identification of a GW compact binary merger candidate
  29. Fermi GRB 240514B: Global MASTER-Net observations report
  30. transient: Xinglong Nearby Galaxy Supernova Survey detection of AT2024iss
  31. GRB 240514B: Fermi GBM Final Real-time Localization
  32. LIGO/Virgo/KAGRA S240507p: Upper limits from Swift/BAT-GUANO
  33. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  34. LIGO/Virgo/KAGRA S240505av: Upper limits from Swift/BAT-GUANO
  35. GRB 240514A: Fermi GBM Final Real-time Localization
  36. GRB 240513A: Tiled Swift observations
  37. LAT GRB240513.31: Global MASTER-Net observations report
  38. GRB 240513A: Fermi-LAT detection
  39. LIGO/Virgo/KAGRA S240513ei: Identification of a GW compact binary merger candidate
  40. GRB 240511A: Fermi GBM Observation
  41. GRB 240511A: Swift-BAT refined analysis
  42. Fermi GRB 240513B: Global MASTER-Net observations report
  43. Fermi trigger No 737277727: Global MASTER-Net observations report
  44. GRB 240513B: Fermi GBM Final Real-time Localization
  45. GRB 240513A: AstroSat CZTI detection
  46. LIGO/Virgo/KAGRA S240513cx: Coverage and upper limits from MAXI/GSC observations
  47. Fermi trigger No 737258655: Global MASTER-Net observations report
  48. GRB 240511A: J-band observations with WINTER
  49. Fermi trigger No 737247400: Global MASTER-Net observations report
  50. Fermi trigger No 737244199: Global MASTER-Net observations report
  51. Fermi trigger No 737218721: Global MASTER-Net observations report
  52. Fermi trigger No 737196587: Global MASTER-Net observations report
  53. Fermi trigger No 737168073: Global MASTER-Net observations report
  54. GRB 240511A: Enhanced Swift-XRT position
  55. GRB 240511A : MITSuME Akeno optical upper limits
  56. LIGO/Virgo/KAGRA S240512r: Updated Sky localization and EM Bright Classification
  57. GRB 240511A: Swift-XRT refined Analysis
  58. GRB 240511A: optical afterglow detection from the NOT
  59. Fermi Gamma-ray Burst Monitor trigger 737102480/240511279 is not a GRB
  60. Fermi Gamma-ray Burst Monitor trigger 737111207/240511380 is not a GRB
  61. Fermi GBM trigger 737105243/240511311 is not a GRB
  62. Fermi trigger No 737173236: Global MASTER-Net observations report
  63. LIGO/Virgo/KAGRA S240512r: Identification of a GW compact binary merger candidate
  64. Fermi GRB 240511A: Global MASTER-Net observations report
  65. Swift GRB 240511A: Global MASTER-Net observations report
  66. Fermi trigger No 737105243: Global MASTER-Net observations report
  67. Fermi Gamma-ray Burst Monitor trigger 737133200/240511634 is not a GRB
  68. Fermi trigger No 737152719: Global MASTER-Net observations report
  69. GRB 240511A: Prompt enhanced Swift-XRT position
  70. GRB 240511A: Swift detection of a burst
  71. LIGO/Virgo/KAGRA S240511i: Updated Sky localization
  72. GRB 240511A: Fermi GBM Final Real-time Localization
  73. Fermi trigger No 737102480: Global MASTER-Net observations report
  74. Fermi trigger No 737111207: Global MASTER-Net observations report
  75. LIGO/Virgo/KAGRA S240511i: Identification of a GW compact binary merger candidate
  76. LIGO/Virgo/KAGRA S240422ed: GMOS-S photometry of J-GEM24a
  77. LIGO/Virgo/KAGRA S240422ed: P200 observations of AT2024hit
  78. LIGO/Virgo/KAGRA S240422ed: Candidates from the latest GW-MMADS DECam Observations
  79. Fermi trigger No 736967879: Global MASTER-Net observations report
  80. EP240506a: Xinglong optical upper limit
  81. Fermi Gamma-ray Burst Monitor trigger 230925241/717313591 is not a GRB
  82. EP240506a: CrAO ZTSH optical upper limit
  83. GRB 240504A: Fermi GBM Observation
  84. Fermi Gamma-ray Burst Monitor trigger 736837160/240508208 is not a GRB
  85. EP240506a: Archival radio searching
  86. EP240506a: TRT optical upper limit
  87. EP240506a: BOOTES Network optical upper limit
  88. LIGO/Virgo/KAGRA S240507p: Updated Sky localization and EM Bright Classification
  89. LIGO/Virgo/KAGRA S240422ed: Upper limits from a two-week IceCube neutrino search
  90. Fermi trigger No 736733320: Global MASTER-Net observations report
  91. EP240506a: Optical upper limit with Kinder observations
  92. IPN triangulation of GRB 240504A
  93. GRB 240502A: 1.3m DFOT Optical upper limit
  94. EP240506a: EP-WXT detection of a new fast X-ray transient
  95. LIGO/Virgo/KAGRA S240507p: Identification of a GW compact binary merger candidate
  96. LIGO/Virgo/KAGRA S240422ed: Additional WINTER near-infrared J-band observations
  97. LIGO/Virgo/KAGRA S240422ed: Swope Follow-up of AT2024hfr and AT2024hfs
  98. GRB 240504A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  99. Fermi GBM triggers 736668287/240506253 and 736669277/240506265 are not GRBs
  100. LIGO/Virgo/KAGRA S240505av: Updated Sky localization and EM Bright Classification

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