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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"

21771 results found.

  1. GRB 090720B: Fermi GBM detection
  2. Swift XRT and UVOT refned analysis of GRB 090720
  3. GRB 090715B: VLA radio detection
  4. GRB 090720 Source found in ground processing of Swift-BAT data
  5. GRB 090717: Fermi GBM detection
  6. GRB 090719: Fermi GBM detection
  7. GRB 090718B: Fermi GBM detection
  8. GRB 090715B: further NOT optical observations
  9. GRB 090715A: Suzaku WAM observation of the prompt emission
  10. GRB 090709A - CARMA mm Observations
  11. GRB 090715A: VLA observations
  12. Konus-Wind observations of short/hard GRB 090715A
  13. GRB 090715B: Swift/UVOT followup observations
  14. GRB 090715B: Enhanced Swift-XRT position
  15. GRB 090715B: Observation of the optical afterglow
  16. GRB 090715B: NOT optical observations
  17. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  18. GRB 090715A: ROTSE-III Optical Limits
  19. GRB 090713: Fermi GBM detection
  20. VLA radio observations of GRB 090709A
  21. GRB 090621B: MTM-500 optical observations
  22. GRB 090709A: Suzaku WAM observation of the prompt emission
  23. GRB 090709A: Swift UVOT upper limits
  24. GRB 090709A: WHT LIRIS observations
  25. Konus-Wind and Konus-RF observations of GRB 090709A
  26. GRB 090709A: P60 Observations
  27. GRB 090709A: NOT optical observations
  28. GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
  29. GRB 090709B, Swift-BAT refined analysis
  30. GRB 090709A: Swift-BAT refined analysis
  31. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  32. GRB 090709A, RIMOTS optical upper limits
  33. GRB 090709A: Enhanced Swift-XRT position
  34. GRB 090709A: Subaru NIR observation
  35. GRB 090709 : planned Suzaku-ToO observation
  36. GRB 090709: Faulkes Telescope North Upper Limits
  37. GRB 090626: Suzaku WAM observation of the prompt emission
  38. GRB 090709: PAIRITEL NIR Upper Limits
  39. GRB 090709: ROTSE-III Optical Limits
  40. GRB 090709: Swift detection of a bright burst
  41. GRB 090708: Early RAPTOR Optical Limits
  42. GRB 090708, Swift-BAT refined analysis
  43. GRB 090708: ROTSE-III Optical Limits
  44. GRB 090705: PAIRITEL NIR Observations
  45. GRB 090705: Swift detection of a possible burst
  46. XRF 090702 : RTT150 optical observations
  47. GRB 090529: CrAO optical upper limit
  48. GRB 090529: MTM-500 optical observations
  49. XRF 090702: Swift-XRT refined analysis
  50. GRB 090702: UVOT upper limits
  51. XRF 090702: VLT imaging
  52. XRF 090702: Swift-XRT afterglow position
  53. GRB 090404: Deep optical imaging and possible host association
  54. GRB 090628: Swift/UVOT Upper Limits
  55. Konus-Wind observation of GRB 090626
  56. GRB080628: SAO RAS optical observations
  57. GRB 090628: GROND upper limits
  58. GRB 090628: Enhanced Swift-XRT position
  59. GRB 090626: IPN localization
  60. GRB 090628: Swift detection of a burst
  61. GRB 090423: Spitzer observations of the z~8.3 burst
  62. GRB 090625B: Swift/UVOT Upper Limits
  63. GRB 090625B: GROND upper limits
  64. GRB 090623: Suzaku WAM observation of the prompt emission
  65. GRB090618: HCT optical observations
  66. GRB 090618: SARA Second Epoch Observations
  67. GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
  68. GRB 090617: Suzaku WAM observation of the prompt emission
  69. GRB 090618: Suzaku WAM observation of the prompt emission
  70. GRB 090621A: Enhanced Swift-XRT position
  71. GRB 090621B: GRT Optical Observation
  72. GRB 090621A: GRT Optical Observation
  73. GRB 090621B: I-band observations from 1.23m CAHA
  74. GRB 090621B: P60 Observations
  75. GRB 090621B: VLA observations
  76. Konus-Wind and Konus-RF observations of GRB 090618
  77. GRB 090621B: Swift/UVOT Upper Limits
  78. GRB 090621B: RTT150 optical observations
  79. GRB 090621B: Swift detection of a short hard burst
  80. GRB 090621: Swift/UVOT Upper Limits
  81. GRB090618: Spectrum and photometry from 6.0m BTA
  82. GRB 090621: Swift detection of a burst
  83. GRB090618: OAA-OAUV Optical observations
  84. VLA radio detection of GRB 090618
  85. GRB 090618 15GHz radio detection
  86. GRB090618 - Continued optical monitoring and light curve break
  87. GRB 090618: Swift-BAT refined analysis
  88. GRB 090618: SARA observations
  89. GRB090618: Swift/UVOT bright afterglow detection
  90. GRB 090618: SDSS host detection
  91. Swift XRT observations of GRB 090531A
  92. GRB 090618: AGILE observations
  93. GRB 090618: Enhanced Swift-XRT position
  94. GRB 090618 Faulkes Telescope North observations
  95. GRB090618: P60 Optical Afterglow
  96. GRB 090618: Swift detection of a bright burst with optical afterglow
  97. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  98. GRB 090602: Suzaku WAM observation of the prompt emission
  99. GRB 090424: WSRT Radio Observations
  100. RXTE Discovery of Pulsations from SGR 0418+5729

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