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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"

28053 results found.

  1. GRB110106A, mm-radio observations
  2. GRB 101219B: GROND detection of a SN signature
  3. Swift-BAT trigger 442771 is a noise fluctuation
  4. New feature in Fermi GBM GRB Ground Position Notices
  5. Swift-BAT Trigger 442539 is not a GRB
  6. Swift Trigger 442539 is probably not a GRB
  7. Short GRB 110112B : early optical limit by "Pi of the Sky"
  8. GRB101225A - timing analysis
  9. GRB 110112B: Swift XRT and UVOT observations of the INTEGRAL burst
  10. GRB 110112A: MITSuME Akeno and Okayama optical upper limits
  11. GRB 110107A: Swift-XRT afterglow confirmation
  12. GRB 101225A: HST observations - no host detected
  13. GRB 110112A: Swift-XRT refined Analysis
  14. GRB 110112A: Swift/UVOT upper limits
  15. GRB 110112A: WHT candidate afterglow/host galaxy
  16. GRB 110112A: Swift-BAT refined analysis
  17. GRB 110112A: Enhanced Swift-XRT position
  18. GRB110112A: TNT optical afterglow candidate
  19. GRB 110112A: Swift detection of a possible short burst
  20. GRB 110107A: Swift/UVOT upper limits
  21. GRB 101219b. Possible radio afterglow detection.
  22. GRB 110107A: Swift-XRT Afterglow Candidate
  23. GRB 110106B: Fermi GBM detection
  24. GRB 110106B: Swift-XRT refined Analysis
  25. GRB 110106A: TNG NIR observations
  26. GRB 110106A: ISAS-Kanazawa optical upper limit
  27. GRB 110106A: MITSuME Okayama optical upper limits
  28. GRB 110106B: Swift-BAT refined analysis
  29. GRB 110106B: Enhanced Swift-XRT position
  30. GRB 110106A: Swift/UVOT Upper Limits
  31. GRB 110106A: TNG redshift of the closeby galaxy
  32. GRB 110106A: Swift-XRT refined Analysis
  33. GRB 110106A: Swift-BAT refined analysis
  34. GRB 110106A: Enhanced Swift-XRT position
  35. GRB 110106B: Swift detection of a burst
  36. GRB 110106A: TNG optical observations and candidate counterparts
  37. GRB 110106A: Swift detection of a burst
  38. GRB 101225A: Host galaxy
  39. GRB 110102A: Swift-XRT refined Analysis
  40. GRB110102A: Swift/UVOT observations
  41. GRB110102A: MITSuME Okayama Optical Observation
  42. GRB 110102A: Fermi GBM observation
  43. GRB 110102A: Swift-BAT refined analysis
  44. GRB 110102A: Enhanced Swift-XRT position
  45. GRB 110102A: Swift detection of a burst with an optical detection
  46. GRB 101225A: optical break from NOT observation
  47. GRB 101225A: P60 Observations
  48. GRB 101225A: MAXI/GSC observations
  49. GRB 101225A Late-time emission observed by Swift-BAT
  50. Tentative redshift of GRB101225A (Christmas's burst) from Swift-XRT data
  51. GRB 101225A, Swift-BAT refined analysis
  52. GRB 101225A: Swift/UVOT Detection
  53. GRB 101225A: Swift-XRT refined Analysis
  54. GRB 101225A: Enhanced Swift-XRT position
  55. Trigger 441015 / GRB 101225A: Further NOT optical observation
  56. Trigger 441015 / GRB 101225A: NOT optical afterglow candidate
  57. GRB 101225A (Swift trigger 441015): optical upper limit
  58. Trigger 441015: Swift detection of a possible burst or transient
  59. GRB 101224A: NOT optical observation
  60. GRB 101224A: Pre-event imaging from DeepSky; Detection of a source in the XRT error circle
  61. GRB 101224A: Swift/UVOT Upper Limits
  62. GRB 101224A: Swift-XRT refined Analysis
  63. GRB101224A: MITSuME Okayama optical upper limits
  64. GRB 101224A, Swift-BAT refined analysis
  65. GRB 101224A - UVOT-enhanced XRT position
  66. GRB 101224A: Swift detection of a short burst
  67. GRB 101219A: Chandra Observations
  68. GRB 101219B: Swift/UVOT refined analysis
  69. GRB 101219B: Swift-XRT refined Analysis
  70. GRB 101219B: Enhanced Swift-XRT position
  71. GRB 101219A: MITSuME Ishigakijima Optical upper limits
  72. GRB 101219B: GROND Detection of the Optical/NIR Afterglow
  73. GRB 101219B: Fermi GBM observation
  74. GRB 101219A: IAC80 optical observations
  75. GRB 101219B: Swift-BAT refined analysis
  76. GRB 101219A: Swift-XRT refined Analysis
  77. GRB 101219B: Swift detection of a burst with an optical afterglow
  78. GRB 101219A: Swift/UVOT Upper Limits
  79. GRB 101219A: GROND Upper limits
  80. GRB 101219A: Magellan NIR observations
  81. GRB 101219A: Further Gemini-South Imaging
  82. GRB 101219A: Swift-BAT refined analysis
  83. GRB 101219A - NOT observation - upper limit
  84. GRB 101219A: SARA-N Upper Limit
  85. GRB 101219A: REM optical and NIR observations
  86. GRB 101219A: Swift detection of a short hard burst
  87. GRB 101213A : Suzaku WAM observation of the prompt emission
  88. Redshift solution(s) for GRB101213A from Swift-XRT data
  89. XRF 101117A, RIMOTS optical upper limits
  90. GRB 101213A: Fermi GBM observation
  91. GRB 101213A, Swift-BAT refined analysis
  92. GRB 101213A: Swift-XRT refined Analysis
  93. GRB 101213A: Swift/UVOT Upper Limits
  94. GRB 101213A: Enhanced Swift-XRT position
  95. GRB 101213: object within the X-ray error circle
  96. GRB 101213A: Swift detection of a burst
  97. GRB101204A: Swift/UVOT observations
  98. GRB 101204A: Swift-XRT refined Analysis
  99. GRB101204A GROND Detection of the Optical/NIR Afterglow
  100. GRB 101204A Afterglow Candidate, VATT Observations

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