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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"

19576 results found.

  1. GRB 090720B: Fermi GBM detection
  2. Swift XRT and UVOT refned analysis of GRB 090720
  3. GRB 090709A: Swift XRT Timing Analysis
  4. GRB 090715B: VLA radio detection
  5. GRB 090720 Source found in ground processing of Swift-BAT data
  6. GRB 090717B: Fermi GBM detection
  7. GRB 090717: Fermi GBM detection
  8. GRB 090719: Fermi GBM detection
  9. GRB 090718B: Fermi GBM detection
  10. GRB 090720: Fermi GBM detection
  11. GRB 090715B: further NOT optical observations
  12. GRB 090709A - CARMA mm Observations
  13. GRB 090715A: VLA observations
  14. GRB 090715B: Swift/UVOT followup observations
  15. GRB 090715B: Enhanced Swift-XRT position
  16. GRB 090715B: Observation of the optical afterglow
  17. GRB 090715B: NOT optical observations
  18. GRB 090715B: Swift detection of a burst with a possible optical counterpart
  19. GRB 090712: Fermi GBM observation
  20. GRB 090713: Fermi GBM detection
  21. VLA radio observations of GRB 090709A
  22. GRB 090621B: MTM-500 optical observations
  23. GRB 090709A: deep optical observation with the 10.4m GTC
  24. GRB 090709A: Swift UVOT upper limits
  25. GRB 090709A: WHT LIRIS observations
  26. GRB 090709B: Fermi GBM detection
  27. GRB 090709A: confirmation of the periodicity in the SPI-ACS data
  28. GRB 090709A: P60 Observations
  29. GRB 090709A: Quasiperiodic variations in the BAT light curve
  30. GRB 090709A: NOT optical observations
  31. GRB 090709A: RAPTOR Limits During Gamma-Ray Emission
  32. GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift
  33. GRB 090709A: Wyoming Infrared Observatory NIR upper limits
  34. GRB 090709A, RIMOTS optical upper limits
  35. GRB 090709A: Enhanced Swift-XRT position
  36. GRB 090709A: Subaru NIR observation
  37. GRB 090709 : planned Suzaku-ToO observation
  38. GRB 090708 : Fermi GBM detection
  39. GRB 090709: Faulkes Telescope North Upper Limits
  40. GRB 090709: PAIRITEL NIR Upper Limits
  41. GRB 090704: Fermi GBM observation
  42. GRB 090709: Swift detection of a bright burst
  43. GRB 090708: Early RAPTOR Optical Limits
  44. GRB 090708, Swift-BAT refined analysis
  45. GRB 090706: Fermi GBM detection
  46. GRB 090705: PAIRITEL NIR Observations
  47. GRB 090705: Swift detection of a possible burst
  48. XRF 090702 : RTT150 optical observations
  49. GRB 090529: CrAO optical upper limit
  50. GRB 090529: MTM-500 optical observations
  51. GRB 090703: Fermi GBM detection
  52. GRB 090702: UVOT upper limits
  53. XRF 090702: VLT imaging
  54. XRF 090702: Swift-XRT afterglow position
  55. GRB 090404: Deep optical imaging and possible host association
  56. GRB 090701: Fermi GBM detection
  57. GRB 090630: Fermi GBM detection
  58. GRB 090628: Swift/UVOT Upper Limits
  59. GRB080628: SAO RAS optical observations
  60. GRB 090628: GROND upper limits
  61. GRB 090628: Enhanced Swift-XRT position
  62. GRB 090626: IPN localization
  63. GRB 090628: Swift/UVOT Finding Chart Observation
  64. GRB 090625B: Fermi GBM observation
  65. GRB 090423: Spitzer observations of the z~8.3 burst
  66. GRB 090625B: Swift/UVOT Upper Limits
  67. GRB 090626: Fermi GBM detection
  68. GRB 090625B: GROND upper limits
  69. GRB090618: HCT optical observations
  70. GRB 090618: SARA Second Epoch Observations
  71. GRB 090625B: Swift observation of the INTEGRAL GRB 090625B
  72. GRB 090625: Fermi GBM detection
  73. GRB 090621A: Enhanced Swift-XRT position
  74. GRB 090623: Fermi GBM detection
  75. GRB 090621B: GRT Optical Observation
  76. GRB 090621A: GRT Optical Observation
  77. GRB 090621B: Fermi GBM detection
  78. GRB 090621B: I-band observations from 1.23m CAHA
  79. GRB 090621D: Fermi GBM detection
  80. GRB 090621B: Gemini spectrum of afterglow candidate
  81. GRB 090621C: Fermi GBM detection
  82. GRB 090621B: P60 Observations
  83. GRB 090621: Fermi GBM observation
  84. GRB 090621B: VLA observations
  85. GRB 090620: Fermi GBM detecion
  86. Konus-Wind and Konus-RF observations of GRB 090618
  87. GRB 090621B: Swift/UVOT Upper Limits
  88. GRB 090621B: Swift-BAT refined analysis
  89. GRB 090621B: RTT150 optical observations
  90. GRB 090621B: Swift detection of a short hard burst
  91. GRB 090621: Swift/UVOT Upper Limits
  92. GRB090618: Spectrum and photometry from 6.0m BTA
  93. GRB 090621: Swift detection of a burst
  94. GRB090618: OAA-OAUV Optical observations
  95. GRB 090618: Fermi GBM observation
  96. VLA radio detection of GRB 090618
  97. GRB 090618 15GHz radio detection
  98. GRB090618 - Continued optical monitoring and light curve break
  99. GRB 090618: SARA observations
  100. GRB090618: Swift/UVOT bright afterglow detection

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