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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"

36029 results found.

  1. GRB 060719: correction to the coordinates reported in GCN 5347
  2. GRB 060522: VLA observation
  3. GRB 060719: Swift/UVOT Upper Limits
  4. GRB 060719: VLT/ISAAC observations
  5. GRB 060719: Refined analysis of the Swift-BAT burst
  6. GRB 060719: XRT refined analysis
  7. GRB 060719: further analysis of VLT observations
  8. GRB 060719: optical limit by Pi-of-the-Sky
  9. GRB060719: FRAM early follow-up limit
  10. GRB 060719: prompt PROMPT observations
  11. GRB060719: REM NIR Observations
  12. GRB 060719: Continued LCO optical observations
  13. GRB 060719: VLT observations
  14. GRB 060719: LCO optical observations
  15. GRB 060719: Swift detection of a burst
  16. GRB 060717: Swift XRT refined analysis
  17. GRB 060714: OA fading and a possible host detection
  18. GRB060714: optical observations
  19. GRB 060717: NOT observations
  20. GRB 060714: Refined analysis of the Swift-BAT burst
  21. GRB 060717 optical upper limit
  22. GRB060717: Swift/UVOT upper limits
  23. GRB 060717: Swift XRT refined position
  24. GRB 060717: Swift-BAT refined analysis
  25. GRB060717 - SDSS Pre-burst Observations
  26. GRB 060714: REM infrared observations
  27. GRB 060717, optical observation
  28. GRB 060717: Swift detection of a burst
  29. GRB060714: correction to GCN 5324
  30. GRB060714: optical observations
  31. GRB 060714, SMARTS optical/IR afterglow observation
  32. GRB 060714 : Liverpool Telescope Observations
  33. GRB 060714: Swift XRT refined analysis
  34. GRB 060714: OA redshift
  35. GRB 060708: VLT spectroscopy
  36. GRB060708: MARGE low resolution spectrum observations
  37. GRB060714: optical observations
  38. Swift-BAT trigger 219136 is not a GRB
  39. Correction to Circular 5314: Circular refers to GRB 060714
  40. GRB060707 possible optical confirmation
  41. Swift trigger 219136 is probably not a GRB
  42. GRB 060714, optical observation
  43. GRB 060714: Swift detection of a burst with an UVOT optical afterglow
  44. GRB 060605: SkyNet Optical Limits
  45. GRB060712: P60 Observations
  46. GRB 060712: XRT refined analysis
  47. GRB 060712: Swift/UVOT Upper Limits
  48. GRB060526: optical observations
  49. GRB 060712: XRT refined position
  50. GRB 060712: Refined analysis of the Swift-BAT burst
  51. GRB060712: MASTER optical observation
  52. GRB120706: MASTER optical observation
  53. GRB 060712: Swift detection of a burst
  54. Host galaxy of GRB050904: 250 GHz upper limit with MAMBO at the IRAM 30m
  55. GRB 060708: PROMPT Optical Limits
  56. GRB 060707: OA fading and redshift
  57. GRB 060708: Swift-XRT refined analysis
  58. GCN 060708: Swift-UVOT Observations
  59. GRB 060708: Refined analysis of the Swift-BAT burst
  60. GCN 060707: Swift-UVOT observations
  61. GRB 060707: Swift-XRT refined analysis
  62. GRB 060708: Swift detection of a burst with an UVOT countpart
  63. GRB060707 possible optical confirmation
  64. GRB 060707: BOOTES-IR optical afterglow candidate
  65. GRB 060707: Refined analysis of the Swift-BAT burst
  66. GRB 060707: BOOTES-IR optical observation
  67. GRB 060707: Swift detection of a burst
  68. GRB 060515: Upper Limit on Host Galaxy
  69. GRB 050223: Magellan redshift
  70. GRB 060614: SMARTS host galaxy observations
  71. GRB 060614: Detection of a Possible, Late-Time Rebrightening
  72. Correction to GCN 5278 & GCN 5279 (GRBs 060105 & 060109)
  73. GRB 060109: Upper Limit on Host Galaxy
  74. GRB 060105: Upper limit on Host Galaxy
  75. GRB060614: Detection of the host galaxy but no supernova emission
  76. GRB 060614: redshift confirmation
  77. GRB 060614: Redshift
  78. Swift-BAT trigger 215279 is not a GRB
  79. Trigger 215279: Swift detection of a possible burst (GRB 060619)
  80. GRB060614: Optical observations
  81. GRB 060614: spectroscopy
  82. GRB050326: Host Galaxy Candidates
  83. GRB050124: Possible Host Galaxy
  84. GRB050223: Host Galaxy
  85. GRB060512: near IR observations
  86. GRB060526: optical observations
  87. GRB 060614: pseudo-z from spectral parameters of the prompt emission
  88. Konus-Wind observation of GRB 060614
  89. GRB060605: optical observation
  90. The Unusually Long-Lived Afterglow of GRB 060614
  91. GRB 060614: optical observations
  92. GRB 060605, optical observations
  93. GRB 060614, SMARTS optical/IR afterglow observation
  94. GRB060614: SSO 1m observations
  95. GRB060614: Watcher observation
  96. GRB 060614: Swift-BAT refined analysis
  97. GRB 060614: Swift/UVOT Observations
  98. GRB 060604, optical observations
  99. GRB 060614: Swift detection of a burst with a bright optical and X-ray counterpart
  100. GRB 060602A: Swift/XRT analysis

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