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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"

20954 results found.

  1. GRB 110206A: Swift detection of a probable X-ray afterglow
  2. GRB 110206A: TAROT La Silla observatory optical observations
  3. GRB 110205A: Lightbuckets Optical Observations
  4. GRB110205A: SMA 1.3mm Observations
  5. GRB 110205A: Swift/UVOT Continuing Observations
  6. GRB 110205A: Lulin optical observations and temporal decay index
  7. Observations GRB 110205A
  8. GRB 110205A: Newcastle Observatory Optical Observations
  9. GRB 101225A is likely at z~0
  10. GRB 110205A: NOT redshift confirmation
  11. GRB 110205A: FAST Redshift
  12. GRB 110205A: GRAS005 optical observations
  13. GRB 110205A: PAIRITEL NIR Afterglow Detection
  14. GRB 110205A: Swift/UVOT Confirmation of Flaring Afterglow
  15. GRB 110205A: Liverpool Telescope Afterglow Confirmation
  16. GRB 110205A: ROTSE-III, Optical Counterpart is flaring to ~14 mag
  17. GRB 110205A: TAROT Calern observatory optical detection
  18. Swift/UVOT observations of GRB110201A
  19. GRB 110201A: MASTER optical observations
  20. GRB110112B: EVLA Observations
  21. GRB101224A: EVLA Observations
  22. GRB110112A: EVLA Observations
  23. GRB 101112A: Maidanak and CrAO optical observations
  24. GRB110128A: TNG NIR observations
  25. GRB 110128A: Swift/UVOT observations
  26. GRB 110128A: WHT redshifts of nearby field galaxies
  27. GRB 110128A: VLT/X-shooter redshift
  28. GRB 110128A: TAROT Calern observatory upper limits
  29. GRB 110106B, radio observations
  30. GRB 110120A: MASTER optical observations
  31. GRB 110106A: CrAO optical observations
  32. GRB 110120A: MASTER optical observations
  33. GRB110119: Swift/UVOT Detection
  34. GRB 110119A: PAIRITEL NIR Afterglow Detection
  35. GRB110106A, mm-radio observations
  36. GRB 101219B: tentative redshift and spectroscopic supernova detection
  37. GRB 101219B: GROND detection of a SN signature
  38. GRB 101219B: Likely the GRB host emission dominates now in the uvw2 filter
  39. The Christmas burst GRB 101225A - optical spectroscopy with GTC
  40. GRB 110112B: Swift XRT and UVOT observations of the INTEGRAL burst
  41. GRB 101225A: HST observations - no host detected
  42. GRB 101225A: Redshift retraction and results of additional photometric follow-up at the NOT
  43. GRB 110112A: WHT candidate afterglow/host galaxy
  44. GRB 110112A: MASTER optical observations
  45. GRB 110106B: MASTER optical observations
  46. GRB110112A: TNT optical afterglow candidate
  47. GRB 110106B: early optical and near-IR observations
  48. GRB 101225a
  49. GRB 101219b. Possible radio afterglow detection.
  50. GRB 110106B: MASTER early optical observations
  51. GRB 110107A: Swift-XRT Afterglow Candidate
  52. GRB 110107A: Swift-BAT refined analysis
  53. Short GRB 110106A: MASTER OT observations
  54. GRB 110106B: Gemini-North / WHT detection of a fading afterglow
  55. GRB 110106A: TNG NIR observations
  56. GRB 110106B: Liverpool Telescope observations
  57. GRB 110106B: WHT candidate afterglow
  58. GRB 110106A: Swift/UVOT Upper Limits
  59. GRB110106B: Xinglong TNT upper limit
  60. GRB 110106A: TNG optical observations and candidate counterparts
  61. GRB 110106A: MASTER optical observations
  62. GRB 101225A: Keck redshift
  63. GRB110106A: Xinglong TNT upper limit
  64. GRB 101225A: Host galaxy
  65. GRB 101219A: Gemini-North host redshift
  66. GRB 101219B: After 2 weeks still detected by Swift/UVOT
  67. GRB110102A: Swift/UVOT observations
  68. GRB 101225A: MMT spectroscopy
  69. GRB 101225A: P60 Observations
  70. GRB 101225A: MAXI/GSC observations
  71. GRB 101225A Late-time emission observed by Swift-BAT
  72. GRB 101225: Optical follow-up of the Christmas burst
  73. GRB 101225A: WHT observations
  74. Tentative redshift of GRB101225A (Christmas's burst) from Swift-XRT data
  75. GRB 101225A: Swift/UVOT Detection
  76. Trigger 441015 / GRB 101225A: Further NOT optical observation
  77. GRB 101224A: NOT optical observation
  78. GRB 101224A: Pre-event imaging from DeepSky; Detection of a source in the XRT error circle
  79. GRB 101224A: Swift/UVOT Upper Limits
  80. GRB 101219A: Chandra Observations
  81. GRB 101219B: Swift/UVOT refined analysis
  82. GRB 101219B: GROND Detection of the Optical/NIR Afterglow
  83. GRB 101219A: IAC80 optical observations
  84. GRB 101219A: Swift/UVOT Upper Limits
  85. GRB 101219A: GROND Upper limits
  86. GRB 101219A: Magellan NIR observations
  87. GRB 101219A: Further Gemini-South Imaging
  88. GRB 101219A: Gemini-South observations
  89. GRB 101219A: REM optical and NIR observations
  90. GRB 101213A: Swift/UVOT Upper Limits
  91. GRB101204A: Swift/UVOT observations
  92. GRB101204A GROND Detection of the Optical/NIR Afterglow
  93. GRB 101204A Afterglow Candidate, VATT Observations
  94. GRB 101204A Swift-XRT/UVOT afterglow candidate
  95. GRB 101129A SHB found by IPN and in ground analysis of BAT data
  96. GRB 101201A: Swift/UVOT Detection
  97. GRB 101201A: GROND Detection of the Optical/NIR Afterglow
  98. GRB 101123A: ROTSE optical observations
  99. GRB 101123A: MASTER prompt optical observations
  100. Optical observation of GRB 101024A

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