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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"
  1. Konus-Wind and Konus-RF observations of GRB 090719
  2. Konus-RF and Konus-Wind observations of GRB 090718B
  3. Fermi Gamma-ray Burst Monitor triggers 269935914 through 270021937 are not GRBs
  4. Konus-Wind observations of bright hard GRB 090720B
  5. IPN Triangulation of bright GRB 090720B
  6. GRB 090720: Gemini-North Imaging and Optical Afterglow
  7. GRB 090720B: Fermi GBM detection
  8. Swift XRT and UVOT refned analysis of GRB 090720
  9. GRB 090709A: Swift XRT Timing Analysis
  10. GRB 090715B: VLA radio detection
  11. GRB 090720 Source found in ground processing of Swift-BAT data
  12. GRB 090717B: Fermi GBM detection
  13. GRB 090717: Fermi GBM detection
  14. GRB 090719: Fermi GBM detection
  15. GRB 090718B: Fermi GBM detection
  16. GRB 090718: Fermi GBM detection
  17. GRB 090720: Fermi GBM detection
  18. GRB 090715B: further NOT optical observations
  19. GRB 090715A: Suzaku WAM observation of the prompt emission
  20. GRB 090709A - CARMA mm Observations
  21. GRB 090715B: Lick observations
  22. GRB 090715A: VLA observations
  23. Konus-Wind observations of short/hard GRB 090715A
  24. GRB 090715B: MASTER optical limit
  25. GRB 090715A: Swift-BAT refined analysis
  26. Konus-Wind and Konus-RF observations of GRB 090715B
  27. GRB 090715B: Swift/UVOT followup observations
  28. GRB 090715B: break in the optical afterglow decay
  29. GRB 090715B: Enhanced Swift-XRT position
  30. GRB 090715B: Observation of the optical afterglow
  31. GRB 090715B: Swift XRT Refined Analysis
  32. GRB090715B: WHT redshift
  33. GRB 090715B: Swift-BAT refined analysis
  34. GRB 090715B: NOT optical observations
  35. GRB 090715B - Liverpool Telescope Optical Afterglow Candidate
  36. Swift problem fixed
  37. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  38. GRB 090715A: ROTSE-III Optical Limits
  39. GRB 090715: Swift detection of a short hard burst
  40. Detection of GRB 090618 by RT-2 Experiment onboard the CORONAS-PHOTON Satellite
  41. Swift satellite anomaly
  42. GRB090713 optical limit by "Pi of the Sky"
  43. GRB 090712: Fermi GBM observation
  44. GRB 090713: Fermi GBM detection
  45. GRB 090712: Swift-BAT refined analysis
  46. GRB 090712: Swift detection of a burst
  47. GRB 090709A: Xinglong TNT optical upper limit
  48. VLA radio observations of GRB 090709A
  49. GRB 090621B: MTM-500 optical observations
  50. GRB 090709A: deep optical observation with the 10.4m GTC
  51. GRB090709A : WSRT Radio observation
  52. GRB 090709A: Suzaku WAM observation of the prompt emission
  53. GRB 090709A: Swift UVOT upper limits
  54. GRB 090709A: WHT LIRIS observations
  55. GRB 090709B: Fermi GBM detection
  56. GRB 090709A: confirmation of the periodicity in the SPI-ACS data
  57. GRB 090709A: evidence for a very red afterglow at low z
  58. Konus-Wind and Konus-RF observations of GRB 090709A
  59. GRB 090709A: P60 Observations
  60. GRB 090709A: Quasiperiodic variations in the BAT light curve
  61. GRB 090709A: NOT optical observations
  62. GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
  63. GRB 090709A: Swift XRT Refined Analysis
  64. GRB 090709B, Swift-BAT refined analysis
  65. GRB 090709A: Swift-BAT refined analysis
  66. GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
  67. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  68. GRB 090709A, RIMOTS optical upper limits
  69. GRB 090709A: Enhanced Swift-XRT position
  70. GRB 090709A - PAIRITEL Discovery of a Red Afterglow
  71. GRB 090709A: Subaru NIR observation
  72. GRB 090709B: Swift detection of a burst
  73. GRB 090709 : planned Suzaku-ToO observation
  74. GRB 090708 : Fermi GBM detection
  75. GRB 090709: Faulkes Telescope North Upper Limits
  76. GRB 090626: Suzaku WAM observation of the prompt emission
  77. GRB 090709: PAIRITEL NIR Upper Limits
  78. GRB 090704: Fermi GBM observation
  79. GRB 090709: ROTSE-III Optical Limits
  80. GRB 090709: Swift detection of a bright burst
  81. GRB 090708: Early RAPTOR Optical Limits
  82. GRB 090708, Swift-BAT refined analysis
  83. GRB 090708: ROTSE-III Optical Limits
  84. GRB 090708: Swift detection of a burst
  85. GRB 090704: a long GRB found in INTEGRAL off-line analysis
  86. GRB 090706: Fermi GBM detection
  87. Swift-BAT trigger 356516 is not a GRB
  88. Possible GRB090705: Swift-XRT observations
  89. GRB 090705: PAIRITEL NIR Observations
  90. GRB 090705: Swift detection of a possible burst
  91. XRF 090702 : RTT150 optical observations
  92. GRB 090618: Mondy optical observations
  93. GRB 090529: CrAO optical upper limit
  94. GRB 090529: MTM-500 optical observations
  95. GRB 090529: Mt.Terskol optical observations
  96. XRF 090702: Swift-XRT refined analysis
  97. GRB 090703: Fermi GBM detection
  98. GRB 090702: UVOT upper limits
  99. GRB 090313: optical observations
  100. XRF 090702: VLT imaging

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