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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"

333 results found.

  1. GRB 090410: Swift-BAT refined analysis
  2. GRB 090407: Swift UVOT Upper Limits
  3. GRB 090301A: Suzaku WAM observation of the prompt emission
  4. GRB 090206: Fermi GBM detection
  5. GRB 090202: Fermi GBM detection
  6. GRB 080928, Swift-BAT final refined analysis
  7. GRB 080928, Swift-BAT initial refined analysis
  8. GRB 080916A: Swift XRT refined analysis
  9. GRB 080825C: Fermi GBM Spectral Analysis
  10. ATCA radio upper limit on GRB 080723B
  11. GRB 080503, Swift-BAT lag and time-resolved spectral analysis
  12. GRB 080503, Swift-BAT refined analysis
  13. GRB 080413A: Suzaku/WAM and Swift/BAT joint spectral analysis
  14. SAX J1818.6-1703: Swift detection (trigger 306379)
  15. GRB 080205: Swift XRT refined analysis
  16. GRB 070911: Swift/BAT and Suzaku/WAM joint spectral analysis
  17. UVOT observations of SAXJ1810.8-2609
  18. Swift detection of a outburst from SAX J1810.8-2609
  19. GRB 070714B: Swift/UVOT Upper Limits
  20. GRB 070531: Swift-BAT refined analysis
  21. GRB 070520B: Swift-XRT refined analysis
  22. GRB 070318, Swift-BAT refined analysis
  23. GRB 070110: Ep,i - Eiso correlation
  24. GRB 061201: Swift detection of a short hard burst
  25. GRB 061019, Swift-BAT refined analysis
  26. GRB060319: MASTER limit
  27. GRB060319: MASTER optical observation
  28. GRB 050904: early Swift XRT analysis results
  29. Swift/UVOT photometry of GRB050730
  30. GRB050724: Radio Observation
  31. H11603: An X-ray flare from V4641 Sgr, or a possible XRF
  32. Swift/UVOT observation of XRF 050522
  33. GRB050309: CONCAM pre-trigger and trigger coincident optical
  34. Konus-Wind observation of a series SGR 1806-20 bursts on 041005
  35. XMM-Newton Observation of GRB031203
  36. XMM-Newton Observation of GRB031203
  37. IPN triangulation of GRB030421 (annulus)
  38. BeppoSAX GRB : GRB020409
  39. GRB020322: Candidate Optical Afterglow
  40. Bepposax GRB020322 The second springtime BSAX GRB
  41. GRB 011211 Optical Observations: Likely Afterglow
  42. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  43. GRB011121: BeppoSAX-WFC refined positions
  44. BEPPOSAX GRB011121
  45. The X-ray Flash 011030 ('GRB 011030')
  46. IPN triangulation of GRB010629
  47. Support extension to the BeppoSAX mission
  48. GRB010222: possible optical counterpart
  49. GRB010222
  50. GRB 010214, Optical Observations
  51. GRB000528, Radio Observations
  52. IPN triangulation of GRB000516
  53. BeppoSAX GRB000424
  54. GRB000419 [IPN Position]
  55. 1SAXJ1715.0-7134 refined position
  56. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  57. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  58. Budget cuts in BeppoSAX operations: impact on GRB observations
  59. GRB000226 [IPN Position]
  60. GRB 000210: BATSE Observations
  61. GRB000210, Radio Observations
  62. SAX_WFC_GRB_NOTICE
  63. SAX_WFC_GRB_NOTICE
  64. GCN resumes full operations
  65. IPN error box for GRB991216
  66. GRB 991217 (SAX J2303.2+0015) Optical observations
  67. GRB991217/SAX J2303.2+0015, optical observations
  68. SAX J2303.2+0015 Optical observations
  69. GRB 991217 (SAX J2303.2+0015) Optical observations
  70. GRB 991217
  71. SAX J2303.2+0015: an x-ray/GRB?
  72. BeppoSAX NFI Observation of GRB991106
  73. GRB 991105: BATSE Observations
  74. BeppoSAX refined position for GRB991106
  75. GRB991105: SAX-GRBM/-WFC detection
  76. BeppoSAX MAIL n. 99/30: GRB991105 refined position (fwd)
  77. GRB ALERT: GRB991105
  78. GRB 991014 - X-ray afterglow identification by BeppoSAX-NFI
  79. GRB990908, another BeppoSAX-GRBM/WFC burst detection
  80. GRB990806 BeppoSAX follow up
  81. GRB 990712
  82. Infrared and Optical Observations of GRB990705
  83. GRB990704: SAX-NFI results summary
  84. GRB 990704 X-ray Observations
  85. GRB990705: Intriguing Positional Coincidences
  86. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  87. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  88. Optical report on X-ray/GRB transient
  89. BeppoSAX: A new fast X-ray transient
  90. GRB981220 VLBA observations
  91. GRB981220, IPN localization
  92. GRB 981220, radio observations
  93. GRB990123, Probability of gravitational lensing
  94. GRB990123 IPN annulus
  95. GRB990123, refined SAX-WFC position
  96. GRB 990123, Radio observations
  97. Optical Observations of GRB 981220
  98. GRB981220
  99. GRB981220, Optical Observations
  100. GRB 981220 Optical observations

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