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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"

28089 results found.

  1. GRB 090708: Early RAPTOR Optical Limits
  2. GRB 090708, Swift-BAT refined analysis
  3. GRB 090704: a long GRB found in INTEGRAL off-line analysis
  4. GRB 090706: Fermi GBM detection
  5. Possible GRB090705: Swift-XRT observations
  6. GRB 090705: PAIRITEL NIR Observations
  7. GRB 090705: Swift detection of a possible burst
  8. XRF 090702 : RTT150 optical observations
  9. GRB 090529: CrAO optical upper limit
  10. GRB 090529: MTM-500 optical observations
  11. XRF 090702: Swift-XRT refined analysis
  12. GRB 090703: Fermi GBM detection
  13. GRB 090702: UVOT upper limits
  14. XRF 090702: VLT imaging
  15. XRF 090702: Swift-XRT afterglow position
  16. XRF 090702: a long soft GRB localized with INTEGRAL
  17. GRB 090404: Deep optical imaging and possible host association
  18. GRB 090701: Fermi GBM detection
  19. GRB 090628: Swift XRT refined analysis
  20. GRB 090630: Fermi GBM detection
  21. GRB 090628: Swift/UVOT Upper Limits
  22. GRB080628: SAO RAS optical observations
  23. GRB 090628: Swift-BAT refined analysis
  24. GRB 090628: GROND upper limits
  25. GRB 090628: Enhanced Swift-XRT position
  26. GRB 090626: IPN localization
  27. GRB 090423: Spitzer observations of the z~8.3 burst
  28. GRB 090625B: Swift/UVOT Upper Limits
  29. GRB 090625B: Swift-XRT refined analysis
  30. GRB 090626: Fermi GBM detection
  31. GRB 090625B: GROND upper limits
  32. GRB 090623: Suzaku WAM observation of the prompt emission
  33. GRB090618: HCT optical observations
  34. GRB 090618: SARA Second Epoch Observations
  35. GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
  36. GRB 090625B: a long GRB localized by INTEGRAL
  37. GRB 090625: Fermi GBM detection
  38. GRB 090618: Correction to GCN 9568
  39. GRB 090617: Suzaku WAM observation of the prompt emission
  40. GRB 090618: Suzaku WAM observation of the prompt emission
  41. GRB 090621A: Enhanced Swift-XRT position
  42. GRB 090623: Fermi GBM detection
  43. GRB 090621B: GRT Optical Observation
  44. GRB 090621A: GRT Optical Observation
  45. GRB 090621B: I-band observations from 1.23m CAHA
  46. GRB 090621D: Fermi GBM detection
  47. GRB 090621C: Fermi GBM detection
  48. GRB 090621B: P60 Observations
  49. GRB 090621B: VLA observations
  50. GRB 090620: Fermi GBM detecion
  51. GRB 090621B: Swift/UVOT Upper Limits
  52. GRB 090621B: Swift-BAT refined analysis
  53. GRB 090621B: Swift-XRT refined analysis
  54. GRB 090621B: RTT150 optical observations
  55. GRB 090621B: Swift detection of a short hard burst
  56. GRB 090621: Swift/UVOT Upper Limits
  57. GRB 090621: Swift-XRT Team refined analysis
  58. GRB090618: Spectrum and photometry from 6.0m BTA
  59. GRB 090621: Swift detection of a burst
  60. GRB090618, underlying supernova search
  61. GRB090618: OAA-OAUV Optical observations
  62. GRB 090618: Fermi GBM observation
  63. GRB 090618, Swift-BAT refined spectral analysis
  64. VLA radio detection of GRB 090618
  65. GRB 090618 15GHz radio detection
  66. GRB090618 - Continued optical monitoring and light curve break
  67. GRB 090618: Swift-BAT refined analysis
  68. GRB 090618: SARA observations
  69. GRB090618: Swift-XRT team refined analysis
  70. GRB090618: Swift/UVOT bright afterglow detection
  71. GRB 090618: SDSS host detection
  72. Swift XRT observations of GRB 090531A
  73. GRB 090618: AGILE observations
  74. GRB 090617: Fermi GBM detection
  75. GRB 090618: Enhanced Swift-XRT position
  76. GRB 090618 Faulkes Telescope North observations
  77. GRB 090618: ROTSE-III Detection of Optical Counterpart
  78. GRB090618: P60 Optical Afterglow
  79. GRB 090618: Swift detection of a bright burst with optical afterglow
  80. GRB 090616: Fermi GBM detection
  81. GRB 090612: Fermi GBM detection
  82. GRB 090610C: Fermi GBM detection
  83. GRB 090610B: Fermi GBM detection
  84. GRB 090610: Fermi GBM detection
  85. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  86. GRB 090602: Suzaku WAM observation of the prompt emission
  87. RXTE Discovery of Pulsations from SGR 0418+5729
  88. GRB 090531B: Fermi GBM detection
  89. Konus-RF observation of SGR burst 090605A
  90. Discovery of a new soft gamma repeater source, SGR 0418+5729
  91. GRB 090608: Fermi GBM detection
  92. GRB 090606: Fermi GBM detection
  93. GRB 090607: XRT Team Refined Analysis
  94. GRB 090607: Swift/UVOT Upper Limits
  95. GRB 090607: Swift-BAT refined analysis of the SHB
  96. GRB 090607: GRAS001 optical observations
  97. GRB 090607: Faulkes Telescope North observations
  98. GRB 090607: Swift detection of a burst
  99. GRB 090530B: Suzaku WAM observation of the prompt emission
  100. GRB 090530: Further NOT optical observations

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