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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"

27405 results found.

  1. GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
  2. GRB 090709A: Swift XRT Refined Analysis
  3. GRB 090709B, Swift-BAT refined analysis
  4. GRB 090709A: Swift-BAT refined analysis
  5. GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
  6. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  7. GRB 090709A, RIMOTS optical upper limits
  8. GRB 090709A: Enhanced Swift-XRT position
  9. GRB 090709A: Subaru NIR observation
  10. GRB 090709 : planned Suzaku-ToO observation
  11. GRB 090708 : Fermi GBM detection
  12. GRB 090709: Faulkes Telescope North Upper Limits
  13. GRB 090626: Suzaku WAM observation of the prompt emission
  14. GRB 090709: PAIRITEL NIR Upper Limits
  15. GRB 090704: Fermi GBM observation
  16. GRB 090709: Swift detection of a bright burst
  17. GRB 090708: Early RAPTOR Optical Limits
  18. GRB 090708, Swift-BAT refined analysis
  19. GRB 090704: a long GRB found in INTEGRAL off-line analysis
  20. GRB 090706: Fermi GBM detection
  21. Possible GRB090705: Swift-XRT observations
  22. GRB 090705: PAIRITEL NIR Observations
  23. GRB 090705: Swift detection of a possible burst
  24. XRF 090702 : RTT150 optical observations
  25. GRB 090529: CrAO optical upper limit
  26. GRB 090529: MTM-500 optical observations
  27. XRF 090702: Swift-XRT refined analysis
  28. GRB 090703: Fermi GBM detection
  29. GRB 090702: UVOT upper limits
  30. XRF 090702: VLT imaging
  31. XRF 090702: Swift-XRT afterglow position
  32. XRF 090702: a long soft GRB localized with INTEGRAL
  33. GRB 090404: Deep optical imaging and possible host association
  34. GRB 090701: Fermi GBM detection
  35. GRB 090628: Swift XRT refined analysis
  36. GRB 090630: Fermi GBM detection
  37. GRB 090628: Swift/UVOT Upper Limits
  38. GRB080628: SAO RAS optical observations
  39. GRB 090628: Swift-BAT refined analysis
  40. GRB 090628: GROND upper limits
  41. GRB 090628: Enhanced Swift-XRT position
  42. GRB 090626: IPN localization
  43. GRB 090423: Spitzer observations of the z~8.3 burst
  44. GRB 090625B: Swift/UVOT Upper Limits
  45. GRB 090625B: Swift-XRT refined analysis
  46. GRB 090626: Fermi GBM detection
  47. GRB 090625B: GROND upper limits
  48. GRB 090623: Suzaku WAM observation of the prompt emission
  49. GRB090618: HCT optical observations
  50. GRB 090618: SARA Second Epoch Observations
  51. GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
  52. GRB 090625B: a long GRB localized by INTEGRAL
  53. GRB 090625: Fermi GBM detection
  54. GRB 090618: Correction to GCN 9568
  55. GRB 090617: Suzaku WAM observation of the prompt emission
  56. GRB 090618: Suzaku WAM observation of the prompt emission
  57. GRB 090621A: Enhanced Swift-XRT position
  58. GRB 090623: Fermi GBM detection
  59. GRB 090621B: GRT Optical Observation
  60. GRB 090621A: GRT Optical Observation
  61. GRB 090621B: I-band observations from 1.23m CAHA
  62. GRB 090621D: Fermi GBM detection
  63. GRB 090621C: Fermi GBM detection
  64. GRB 090621B: P60 Observations
  65. GRB 090621B: VLA observations
  66. GRB 090620: Fermi GBM detecion
  67. GRB 090621B: Swift/UVOT Upper Limits
  68. GRB 090621B: Swift-BAT refined analysis
  69. GRB 090621B: Swift-XRT refined analysis
  70. GRB 090621B: RTT150 optical observations
  71. GRB 090621B: Swift detection of a short hard burst
  72. GRB 090621: Swift/UVOT Upper Limits
  73. GRB 090621: Swift-XRT Team refined analysis
  74. GRB090618: Spectrum and photometry from 6.0m BTA
  75. GRB 090621: Swift detection of a burst
  76. GRB090618, underlying supernova search
  77. GRB090618: OAA-OAUV Optical observations
  78. GRB 090618: Fermi GBM observation
  79. GRB 090618, Swift-BAT refined spectral analysis
  80. VLA radio detection of GRB 090618
  81. GRB 090618 15GHz radio detection
  82. GRB090618 - Continued optical monitoring and light curve break
  83. GRB 090618: Swift-BAT refined analysis
  84. GRB 090618: SARA observations
  85. GRB090618: Swift-XRT team refined analysis
  86. GRB090618: Swift/UVOT bright afterglow detection
  87. GRB 090618: SDSS host detection
  88. Swift XRT observations of GRB 090531A
  89. GRB 090618: AGILE observations
  90. GRB 090617: Fermi GBM detection
  91. GRB 090618: Enhanced Swift-XRT position
  92. GRB 090618 Faulkes Telescope North observations
  93. GRB 090618: ROTSE-III Detection of Optical Counterpart
  94. GRB090618: P60 Optical Afterglow
  95. GRB 090618: Swift detection of a bright burst with optical afterglow
  96. GRB 090616: Fermi GBM detection
  97. GRB 090612: Fermi GBM detection
  98. GRB 090610C: Fermi GBM detection
  99. GRB 090610B: Fermi GBM detection
  100. GRB 090610: Fermi GBM detection

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