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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"

27292 results found.

  1. GRB 090719: Fermi GBM detection
  2. GRB 090718B: Fermi GBM detection
  3. GRB 090718: Fermi GBM detection
  4. GRB 090720: Fermi GBM detection
  5. GRB 090715A: Suzaku WAM observation of the prompt emission
  6. GRB 090709A - CARMA mm Observations
  7. Konus-Wind observations of short/hard GRB 090715A
  8. GRB 090715B: MASTER optical limit
  9. GRB 090715A: Swift-BAT refined analysis
  10. GRB 090715B: Swift/UVOT followup observations
  11. GRB 090715B: break in the optical afterglow decay
  12. GRB 090715B: Enhanced Swift-XRT position
  13. GRB 090715B: Swift XRT Refined Analysis
  14. GRB 090715B: Swift-BAT refined analysis
  15. GRB 090715B - Liverpool Telescope Optical Afterglow Candidate
  16. Swift problem fixed
  17. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  18. GRB 090715A: ROTSE-III Optical Limits
  19. GRB 090715: Swift detection of a short hard burst
  20. Detection of GRB 090618 by RT-2 Experiment onboard the CORONAS-PHOTON Satellite
  21. Swift satellite anomaly
  22. GRB 090712: Fermi GBM observation
  23. GRB 090713: Fermi GBM detection
  24. GRB 090712: Swift-BAT refined analysis
  25. GRB 090712: Swift detection of a burst
  26. GRB 090621B: MTM-500 optical observations
  27. GRB 090709A: deep optical observation with the 10.4m GTC
  28. GRB 090709A: Suzaku WAM observation of the prompt emission
  29. GRB 090709A: Swift UVOT upper limits
  30. GRB 090709B: Fermi GBM detection
  31. GRB 090709A: confirmation of the periodicity in the SPI-ACS data
  32. GRB 090709A: evidence for a very red afterglow at low z
  33. GRB 090709A: Quasiperiodic variations in the BAT light curve
  34. GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
  35. GRB 090709A: Swift XRT Refined Analysis
  36. GRB 090709B, Swift-BAT refined analysis
  37. GRB 090709A: Swift-BAT refined analysis
  38. GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
  39. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  40. GRB 090709A, RIMOTS optical upper limits
  41. GRB 090709A: Enhanced Swift-XRT position
  42. GRB 090709A - PAIRITEL Discovery of a Red Afterglow
  43. GRB 090709B: Swift detection of a burst
  44. GRB 090708 : Fermi GBM detection
  45. GRB 090709: Faulkes Telescope North Upper Limits
  46. GRB 090709: PAIRITEL NIR Upper Limits
  47. GRB 090709: ROTSE-III Optical Limits
  48. GRB 090709: Swift detection of a bright burst
  49. GRB 090708: Early RAPTOR Optical Limits
  50. GRB 090708, Swift-BAT refined analysis
  51. GRB 090708: ROTSE-III Optical Limits
  52. GRB 090708: Swift detection of a burst
  53. GRB 090706: Fermi GBM detection
  54. Swift-BAT trigger 356516 is not a GRB
  55. Possible GRB090705: Swift-XRT observations
  56. GRB 090705: PAIRITEL NIR Observations
  57. GRB 090705: Swift detection of a possible burst
  58. XRF 090702 : RTT150 optical observations
  59. GRB 090618: Mondy optical observations
  60. GRB 090529: CrAO optical upper limit
  61. GRB 090529: MTM-500 optical observations
  62. GRB 090529: Mt.Terskol optical observations
  63. XRF 090702: Swift-XRT refined analysis
  64. GRB 090703: Fermi GBM detection
  65. GRB 090702: UVOT upper limits
  66. XRF 090702: Swift-XRT afterglow position
  67. GRB 090701: Fermi GBM detection
  68. GRB 090628: Swift XRT refined analysis
  69. GRB 090630: Fermi GBM detection
  70. GRB 090618: RTT150 optical observations
  71. GRB 090628: Swift/UVOT Upper Limits
  72. GRB 090628: Swift-BAT refined analysis
  73. GRB 090628: GROND upper limits
  74. GRB 090628: Enhanced Swift-XRT position
  75. GRB 090626: IPN localization
  76. GRB 090628: Swift/UVOT Finding Chart Observation
  77. GRB 090628: Swift XRT position
  78. GRB 090628: Swift detection of a burst
  79. GRB 090625B: Swift/UVOT Upper Limits
  80. GRB 090625B: Swift-XRT refined analysis
  81. GRB 090626: Fermi GBM detection
  82. GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
  83. GRB 090625: Fermi GBM detection
  84. GRB 090621A: Enhanced Swift-XRT position
  85. GRB 090623: Fermi GBM detection
  86. GRB 090621B: GRT Optical Observation
  87. GRB 090621A: GRT Optical Observation
  88. PAIRITEL observations of GRB 090618
  89. GRB 090621B: Fermi GBM detection
  90. GRB 090621B: I-band observations from 1.23m CAHA
  91. GRB 090621D: Fermi GBM detection
  92. GRB 090621C: Fermi GBM detection
  93. GRB 090621: Fermi GBM observation
  94. GRB 090621B: Swift/UVOT Upper Limits
  95. GRB 090621B: Swift-BAT refined analysis
  96. GRB 090621B: Swift-XRT refined analysis
  97. GRB 090621B: RTT150 optical observations
  98. GRB 090618: RTT150 optical observations
  99. GRB 090621A: Swift-BAT refined analysis
  100. GRB 090621B: Swift detection of a short hard burst

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