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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"

28057 results found.

  1. GRB 110402A: Swift-XRT refined Analysis
  2. GRB 110402A: early optical limit by "Pi of the Sky"
  3. GRB 110402A: further NOT observations
  4. GRB110328A/Swift J164449.3+573451: Fermi LAT Observations
  5. GRB 110402A: PAIRITEL NIR Upper Limits
  6. GRB 110402A: Enhanced Swift-XRT position
  7. GRB 110402A: NOT afterglow confirmation
  8. GRB 110402A: Swift detection of a burst
  9. GRB 110328A / Swift J164449.3+57345: Correction to GCN 11850
  10. GRB 110328A / Swift J164449.3+573451: Radio-optical/NIR Astrometry
  11. GRB 110328A / Swift J164449.3+573451: Mondy optical observations
  12. GRB 110328A / Swift J164449.3+573451: KASINICS K-band Observation
  13. GRB 110328A / Swift J164449.3+573451: X-ray analysis and a mini-blazar analogy
  14. GRB 110328A / Swift J164449.3+573451: PAIRITEL NIR Detection in 2nd Epoch
  15. GRB 110328A / Swift J164449.3+573451: No optical variability of the optical counterpart
  16. GRB 110328A / Swift J164449.3+573451: Konkoly observations
  17. GRB 110328A / Swift J164449.3+573451: LOAO R-band Observation
  18. GRB 110328A / Swift J164449.3+573451: PAIRITEL NIR Upper Limits
  19. GRB 110328A / Swift J164449.3+573451: optical observations
  20. GRB 110328A / Swift J164449.3+573451: EVLA Detection
  21. GRB 110328A / Swift J164449.3+573451: optical spectroscopy from GTC
  22. GRB 110213A, the review of the sky area in plate archives
  23. GRB 110328B: Fermi GBM detection
  24. GRB 110328A / Swift J164449.3+573451: NOT optical observations.
  25. GRB / X-ray transient 110328A: MITSuME OkayamaOptical upper limits
  26. GRB 110328A / Swift J164449.3+573451: PTF Quiescent Optical Counterpart
  27. GRB 110328A: Enhanced Swift-XRT position
  28. GRB 110328A: Swift detection of a burst
  29. GRB 110319B Swift-XRT afterglow confirmation
  30. GRB 110319B BAT refined analysis
  31. GRB 110319B: Swift/UVOT Upper Limits
  32. GRB 110318B: Swift/UVOT Upper Limits
  33. GRB 110319B: GROND upper limits
  34. GRB 110319B: Swift-XRT afterglow candidate.
  35. GRB 110319B found in ground analysis of Swift-BAT data
  36. GRB 110319A: Swift/UVOT Detection
  37. GRB 110319A: Swift-BAT refined analysis
  38. GRB 110319A: Swift-XRT refined Analysis
  39. GRB 110318B: GROND upper limits
  40. GRB 110319A: Enhanced Swift-XRT position
  41. GRB 110319A: Swift detection of a burst
  42. GRB 110318B: Swift-XRT refined Analysis
  43. GRB 110318A: Fermi GBM detection
  44. GRB 110318B: Swift-BAT refined analysis
  45. GRB 110318B: Enhanced Swift-XRT position
  46. GRB 110318A: Swift-BAT refined analysis
  47. GRB 110318B: Swift/UVOT Non-Detection of an Afterglow
  48. GRB 110318B: Swift detection of a burst
  49. GRB 110315A: RTT150 optical observations
  50. GRB 110315A: Swift/UVOT Upper Limits
  51. GRB 110315A: Swift-XRT refined Analysis
  52. GRB 110315A: Swift-BAT refined analysis
  53. GRB 110315A: Enhanced Swift-XRT position
  54. GRB 110315A: MASTER early optical observations
  55. GRB 110315A: Swift detection of a burst
  56. GRB110312A: MITSuME Okayama Optical upper limits
  57. GRB 110312A: RTT150 optical observations
  58. GRB 110312A: Swift/UVOT Upper Limits
  59. GRB 110312A: Swift-XRT refined Analysis
  60. GRB 110312A: GROND Upper Limits
  61. GRB 110312A: Enhanced Swift-XRT position
  62. GRB 110312A: Swift-BAT refined analysis
  63. GRB 110312A: Swift detection of a burst
  64. GRB 110305A: REM detection of a possible NIR afterglow
  65. GRB110305A: MITSuME Ishigakijima Optical upper limits
  66. GRB 110305A: Swift/UVOT Upper Limits
  67. GRB 110305A: Swift-XRT refined Analysis
  68. GRB 110305A: Enhanced Swift-XRT position
  69. GRB 110305A: Swift-BAT refined analysis
  70. GRB 110305A: GROND Detection of Optical Afterglow
  71. GRB 110305A: Swift detection of a burst
  72. GRB 110223A: optical upper limits
  73. GRB 110301A: Fermi GBM detection
  74. Swift/UVOT observations of GRB110223A
  75. No IPN GRB detected in conjunction with candidate GRB 110215
  76. IBAS distribution of coordinates for low significance INTEGRAL GRB triggers
  77. Swift/UVOT observations of GRB110223b
  78. GRB 110223A: Swift-BAT refined analysis
  79. GRB 110223A : early optical limit by "Pi of the Sky"
  80. GRB 110223A: Liverpool Telescope observations
  81. GRB 110223A: Swift-XRT refined Analysis
  82. GRB 110223B: Swift-XRT refined Analysis
  83. GRB 110223A: Enhanced Swift-XRT position
  84. GRB 110223B: Enhanced Swift-XRT position
  85. GRB 110223B: Swift-BAT refined analysis
  86. GRB 110223B: GROND Detection of Optical Afterglow Candidate
  87. GRB 110223B: Swift detection of a burst
  88. GRB 110223A: Swift detection of a burst
  89. GRB 101225A, the review of the sky area in plate archives
  90. OT 110215: Further NIR observations from NOT of the GRB candidate
  91. GRB 110213B: Swift/UVOT observations
  92. Fermi GBM detection of an SGR-like burst
  93. Swift XRT and UVOT Observations of OT 110215
  94. OT 110215: NIR observations from NOT of GRB candidate
  95. GRB 110213A: optical observations in CrAO
  96. GRB 110213B: GROND observations of the optical/NIR afterglow
  97. OT 110215: possible GRB from 2MASS J00264184+8324093
  98. Swift/UVOT observations of GRB110210a.
  99. GRB 110210A: optical upper limit
  100. GRB 110210A: ROVOR Upper Limit

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