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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. GRB 090717: Fermi GBM detection
  2. GRB 090719: Fermi GBM detection
  3. GRB 090718B: Fermi GBM detection
  4. GRB 090718: Fermi GBM detection
  5. GRB 090720: Fermi GBM detection
  6. GRB 090715B: further NOT optical observations
  7. GRB 090715A: Suzaku WAM observation of the prompt emission
  8. GRB 090709A - CARMA mm Observations
  9. GRB 090715B: Lick observations
  10. GRB 090715A: VLA observations
  11. Konus-Wind observations of short/hard GRB 090715A
  12. GRB 090715B: MASTER optical limit
  13. GRB 090715A: Swift-BAT refined analysis
  14. Konus-Wind and Konus-RF observations of GRB 090715B
  15. GRB 090715B: Swift/UVOT followup observations
  16. GRB 090715B: break in the optical afterglow decay
  17. GRB 090715B: Enhanced Swift-XRT position
  18. GRB 090715B: Observation of the optical afterglow
  19. GRB 090715B: Swift XRT Refined Analysis
  20. GRB090715B: WHT redshift
  21. GRB 090715B: Swift-BAT refined analysis
  22. GRB 090715B: NOT optical observations
  23. GRB 090715B - Liverpool Telescope Optical Afterglow Candidate
  24. Swift problem fixed
  25. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  26. GRB 090715A: ROTSE-III Optical Limits
  27. GRB 090715: Swift detection of a short hard burst
  28. Detection of GRB 090618 by RT-2 Experiment onboard the CORONAS-PHOTON Satellite
  29. Swift satellite anomaly
  30. GRB090713 optical limit by "Pi of the Sky"
  31. GRB 090712: Fermi GBM observation
  32. GRB 090713: Fermi GBM detection
  33. GRB 090712: Swift-BAT refined analysis
  34. GRB 090712: Swift detection of a burst
  35. GRB 090709A: Xinglong TNT optical upper limit
  36. VLA radio observations of GRB 090709A
  37. GRB 090621B: MTM-500 optical observations
  38. GRB 090709A: deep optical observation with the 10.4m GTC
  39. GRB090709A : WSRT Radio observation
  40. GRB 090709A: Suzaku WAM observation of the prompt emission
  41. GRB 090709A: Swift UVOT upper limits
  42. GRB 090709A: WHT LIRIS observations
  43. GRB 090709B: Fermi GBM detection
  44. GRB 090709A: confirmation of the periodicity in the SPI-ACS data
  45. GRB 090709A: evidence for a very red afterglow at low z
  46. Konus-Wind and Konus-RF observations of GRB 090709A
  47. GRB 090709A: P60 Observations
  48. GRB 090709A: Quasiperiodic variations in the BAT light curve
  49. GRB 090709A: NOT optical observations
  50. GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
  51. GRB 090709A: Swift XRT Refined Analysis
  52. GRB 090709B, Swift-BAT refined analysis
  53. GRB 090709A: Swift-BAT refined analysis
  54. GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
  55. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  56. GRB 090709A, RIMOTS optical upper limits
  57. GRB 090709A: Enhanced Swift-XRT position
  58. GRB 090709A - PAIRITEL Discovery of a Red Afterglow
  59. GRB 090709A: Subaru NIR observation
  60. GRB 090709B: Swift detection of a burst
  61. GRB 090709 : planned Suzaku-ToO observation
  62. GRB 090708 : Fermi GBM detection
  63. GRB 090709: Faulkes Telescope North Upper Limits
  64. GRB 090626: Suzaku WAM observation of the prompt emission
  65. GRB 090709: PAIRITEL NIR Upper Limits
  66. GRB 090704: Fermi GBM observation
  67. GRB 090709: ROTSE-III Optical Limits
  68. GRB 090709: Swift detection of a bright burst
  69. GRB 090708: Early RAPTOR Optical Limits
  70. GRB 090708, Swift-BAT refined analysis
  71. GRB 090708: ROTSE-III Optical Limits
  72. GRB 090708: Swift detection of a burst
  73. GRB 090704: a long GRB found in INTEGRAL off-line analysis
  74. GRB 090706: Fermi GBM detection
  75. Swift-BAT trigger 356516 is not a GRB
  76. Possible GRB090705: Swift-XRT observations
  77. GRB 090705: PAIRITEL NIR Observations
  78. GRB 090705: Swift detection of a possible burst
  79. XRF 090702 : RTT150 optical observations
  80. GRB 090618: Mondy optical observations
  81. GRB 090529: CrAO optical upper limit
  82. GRB 090529: MTM-500 optical observations
  83. GRB 090529: Mt.Terskol optical observations
  84. XRF 090702: Swift-XRT refined analysis
  85. GRB 090703: Fermi GBM detection
  86. GRB 090702: UVOT upper limits
  87. GRB 090313: optical observations
  88. XRF 090702: VLT imaging
  89. XRF 090702: Swift-XRT afterglow position
  90. XRF 090702: a long soft GRB localized with INTEGRAL
  91. GRB 090404: Deep optical imaging and possible host association (correction)
  92. GRB 090404: Deep optical imaging and possible host association
  93. GRB 090701: Fermi GBM detection
  94. GRB 090628: Swift XRT refined analysis
  95. GRB 090630: Fermi GBM detection
  96. GRB 090618: RTT150 optical observations
  97. GRB 090628: Swift/UVOT Upper Limits
  98. Konus-Wind observation of GRB 090626
  99. GRB080628: SAO RAS optical observations
  100. GRB 090628: Swift-BAT refined analysis

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