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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"

42572 results found.

  1. GRB 101219B: correction
  2. GRB 101219B: Likely the GRB host emission dominates now in the uvw2 filter
  3. New feature in Fermi GBM GRB Ground Position Notices
  4. Swift-BAT Trigger 442539 is not a GRB
  5. Swift Trigger 442539 is probably not a GRB
  6. Short GRB 110112B : early optical limit by "Pi of the Sky"
  7. GRB101225A - timing analysis
  8. GRB 110112B: Fermi GBM observation
  9. The Christmas burst GRB 101225A - optical spectroscopy with GTC
  10. GRB 110112B: Swift XRT and UVOT observations of the INTEGRAL burst
  11. GRB 110107A: Swift-XRT afterglow confirmation
  12. GRB 101225A: HST observations - no host detected
  13. GRB 101225A: Redshift retraction and results of additional photometric follow-up at the NOT
  14. GRB 110112B: A short GRB detected by INTEGRAL
  15. GRB 110112A: Swift-XRT refined Analysis
  16. GRB 110112A: Swift/UVOT upper limits
  17. GRB 110112A: WHT candidate afterglow/host galaxy
  18. GRB 110112A: MASTER optical observations
  19. GRB 110112A: Swift-BAT refined analysis
  20. GRB 110112A: Enhanced Swift-XRT position
  21. GRB 110106B: MASTER optical observations
  22. GRB110112A: TNT optical afterglow candidate
  23. GRB 110112A: Swift detection of a possible short burst
  24. GRB 110106B: early optical and near-IR observations
  25. GRB 110107A: Swift/UVOT upper limits
  26. GRB 101225a
  27. GRB 101219b. Possible radio afterglow detection.
  28. GRB 110106B: MASTER early optical observations
  29. GRB 110107A: Swift-XRT Afterglow Candidate
  30. GRB 110107A: Swift-BAT refined analysis
  31. GRB 110107A detected in ground analysis of BAT slew data
  32. GRB 101213A: Gemini-N galaxy redshift
  33. GRB 110106B: Fermi GBM detection
  34. Short GRB 110106A: MASTER OT observations
  35. GRB 110106B: Swift-XRT refined Analysis
  36. GRB 110106B: Gemini-North / WHT detection of a fading afterglow
  37. GRB 110106A: TNG NIR observations
  38. GRB 110106B Gemini-N galaxy redshift
  39. GRB 110106B: Liverpool Telescope observations
  40. GRB 110106B: WHT candidate afterglow
  41. GRB 110106B: Swift-BAT refined analysis
  42. GRB 110106B: Enhanced Swift-XRT position
  43. GRB 110106A: Swift/UVOT Upper Limits
  44. GRB 110106A: TNG redshift of the closeby galaxy
  45. GRB 110106A: Swift-XRT refined Analysis
  46. GRB110106B: Xinglong TNT upper limit
  47. GRB 110106A: Swift-BAT refined analysis
  48. GRB 110106A: Enhanced Swift-XRT position
  49. GRB 110106B: Swift detection of a burst
  50. GRB 110106A: TNG optical observations and candidate counterparts
  51. GRB 110106A: MASTER optical observations
  52. GRB 101225A: Keck redshift
  53. GRB110106A: Xinglong TNT upper limit
  54. GRB 110106A: Swift detection of a burst
  55. GRB 101225A: Host galaxy
  56. GRB 101219A: Gemini-North host redshift
  57. GRB 110102A: Swift-XRT refined Analysis
  58. GRB 101219B: After 2 weeks still detected by Swift/UVOT
  59. Konus-Wind observation of GRB 110102A
  60. GRB110102A: Swift/UVOT observations
  61. GRB 110102A: Fermi GBM observation
  62. GRB 110102A: Swift-BAT refined analysis
  63. GRB 110102A: Enhanced Swift-XRT position
  64. GRB 110102A: Swift detection of a burst with an optical detection
  65. GRB 101225A: optical break from NOT observation
  66. GRB 101225A: MMT spectroscopy
  67. GRB 101225A: P60 Observations
  68. GRB 101225A: MAXI/GSC observations
  69. GRB 101225A Late-time emission observed by Swift-BAT
  70. GRB 101225: Optical follow-up of the Christmas burst
  71. GRB 101225A: WHT observations
  72. Tentative redshift of GRB101225A (Christmas's burst) from Swift-XRT data
  73. GRB 101225A, Swift-BAT refined analysis
  74. GRB 101225A: Swift/UVOT Detection
  75. GRB 101225A: Swift-XRT refined Analysis
  76. GRB 101225A: Enhanced Swift-XRT position
  77. Trigger 441015 / GRB 101225A: Further NOT optical observation
  78. Trigger 441015 / GRB 101225A: NOT optical afterglow candidate
  79. GRB 101225A (Swift trigger 441015): optical upper limit
  80. Trigger 441015: Swift detection of a possible burst or transient
  81. GRB 101224A: NOT optical observation
  82. GRB 101224A: Pre-event imaging from DeepSky; Detection of a source in the XRT error circle
  83. GRB 101224A: Fermi GBM observation
  84. GRB 101224A: Swift-XRT refined Analysis
  85. GRB 101224A, Swift-BAT refined analysis
  86. GRB 101224A - UVOT-enhanced XRT position
  87. GRB 101224A: Swift detection of a short burst
  88. GRB 101219A: Chandra Observations
  89. GRB 101219B: Swift/UVOT refined analysis
  90. GRB 101219B: Swift-XRT refined Analysis
  91. GRB 101219B: Enhanced Swift-XRT position
  92. GRB 101219B: GROND Detection of the Optical/NIR Afterglow
  93. GRB 101219B: Fermi GBM observation
  94. GRB 101219A: IAC80 optical observations
  95. GRB 101219B: Swift-BAT refined analysis
  96. GRB 101219A: Swift-XRT refined Analysis
  97. GRB 101219B: Swift detection of a burst with an optical afterglow
  98. GRB 101219A: GROND Upper limits
  99. Konus-Wind observation of short hard GRB 101219A
  100. GRB 101219A: Magellan NIR observations

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