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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"

27323 results found.

  1. GRB 090715B: Observation of the optical afterglow
  2. GRB 090715B: Swift XRT Refined Analysis
  3. GRB 090715B: Swift-BAT refined analysis
  4. GRB 090715B: NOT optical observations
  5. GRB 090715B - Liverpool Telescope Optical Afterglow Candidate
  6. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  7. GRB 090713: Fermi GBM detection
  8. GRB 090712: Swift-BAT refined analysis
  9. VLA radio observations of GRB 090709A
  10. GRB 090621B: MTM-500 optical observations
  11. GRB 090709A: deep optical observation with the 10.4m GTC
  12. GRB 090709A: Suzaku WAM observation of the prompt emission
  13. GRB 090709A: Swift UVOT upper limits
  14. GRB 090709A: WHT LIRIS observations
  15. GRB 090709B: Fermi GBM detection
  16. GRB 090709A: evidence for a very red afterglow at low z
  17. GRB 090709A: P60 Observations
  18. GRB 090709A: NOT optical observations
  19. GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
  20. GRB 090709A: Swift XRT Refined Analysis
  21. GRB 090709B, Swift-BAT refined analysis
  22. GRB 090709A: Swift-BAT refined analysis
  23. GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
  24. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  25. GRB 090709A, RIMOTS optical upper limits
  26. GRB 090709A: Enhanced Swift-XRT position
  27. GRB 090709A: Subaru NIR observation
  28. GRB 090709 : planned Suzaku-ToO observation
  29. GRB 090708 : Fermi GBM detection
  30. GRB 090709: Faulkes Telescope North Upper Limits
  31. GRB 090626: Suzaku WAM observation of the prompt emission
  32. GRB 090709: PAIRITEL NIR Upper Limits
  33. GRB 090704: Fermi GBM observation
  34. GRB 090709: Swift detection of a bright burst
  35. GRB 090708: Early RAPTOR Optical Limits
  36. GRB 090708, Swift-BAT refined analysis
  37. GRB 090704: a long GRB found in INTEGRAL off-line analysis
  38. GRB 090706: Fermi GBM detection
  39. Possible GRB090705: Swift-XRT observations
  40. GRB 090705: PAIRITEL NIR Observations
  41. GRB 090705: Swift detection of a possible burst
  42. XRF 090702 : RTT150 optical observations
  43. GRB 090529: CrAO optical upper limit
  44. GRB 090529: MTM-500 optical observations
  45. XRF 090702: Swift-XRT refined analysis
  46. GRB 090703: Fermi GBM detection
  47. GRB 090702: UVOT upper limits
  48. XRF 090702: VLT imaging
  49. XRF 090702: Swift-XRT afterglow position
  50. XRF 090702: a long soft GRB localized with INTEGRAL
  51. GRB 090404: Deep optical imaging and possible host association
  52. GRB 090701: Fermi GBM detection
  53. GRB 090628: Swift XRT refined analysis
  54. GRB 090630: Fermi GBM detection
  55. GRB 090628: Swift/UVOT Upper Limits
  56. GRB080628: SAO RAS optical observations
  57. GRB 090628: Swift-BAT refined analysis
  58. GRB 090628: GROND upper limits
  59. GRB 090628: Enhanced Swift-XRT position
  60. GRB 090626: IPN localization
  61. GRB 090423: Spitzer observations of the z~8.3 burst
  62. GRB 090625B: Swift/UVOT Upper Limits
  63. GRB 090625B: Swift-XRT refined analysis
  64. GRB 090626: Fermi GBM detection
  65. GRB 090625B: GROND upper limits
  66. GRB 090623: Suzaku WAM observation of the prompt emission
  67. GRB090618: HCT optical observations
  68. GRB 090618: SARA Second Epoch Observations
  69. GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
  70. GRB 090625B: a long GRB localized by INTEGRAL
  71. GRB 090625: Fermi GBM detection
  72. GRB 090618: Correction to GCN 9568
  73. GRB 090617: Suzaku WAM observation of the prompt emission
  74. GRB 090618: Suzaku WAM observation of the prompt emission
  75. GRB 090621A: Enhanced Swift-XRT position
  76. GRB 090623: Fermi GBM detection
  77. GRB 090621B: GRT Optical Observation
  78. GRB 090621A: GRT Optical Observation
  79. GRB 090621B: I-band observations from 1.23m CAHA
  80. GRB 090621D: Fermi GBM detection
  81. GRB 090621C: Fermi GBM detection
  82. GRB 090621B: P60 Observations
  83. GRB 090621B: VLA observations
  84. GRB 090620: Fermi GBM detecion
  85. GRB 090621B: Swift/UVOT Upper Limits
  86. GRB 090621B: Swift-BAT refined analysis
  87. GRB 090621B: Swift-XRT refined analysis
  88. GRB 090621B: RTT150 optical observations
  89. GRB 090621B: Swift detection of a short hard burst
  90. GRB 090621: Swift/UVOT Upper Limits
  91. GRB 090621: Swift-XRT Team refined analysis
  92. GRB090618: Spectrum and photometry from 6.0m BTA
  93. GRB 090621: Swift detection of a burst
  94. GRB090618, underlying supernova search
  95. GRB090618: OAA-OAUV Optical observations
  96. GRB 090618: Fermi GBM observation
  97. GRB 090618, Swift-BAT refined spectral analysis
  98. VLA radio detection of GRB 090618
  99. GRB 090618 15GHz radio detection
  100. GRB090618 - Continued optical monitoring and light curve break

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