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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"

22917 results found.

  1. GRB 110328A / Swift J164449.3+573451: optical spectroscopy from GTC
  2. GRB 110328B: Fermi GBM detection
  3. GRB 110328A / Swift J164449.3+573451: NOT optical observations.
  4. GRB / X-ray transient 110328A: MITSuME OkayamaOptical upper limits
  5. GRB 110328A / Swift J164449.3+573451: PTF Quiescent Optical Counterpart
  6. GRB 110328A: Enhanced Swift-XRT position
  7. GRB 110328A: Swift detection of a burst
  8. GRB110318B : MOA optical upper limit
  9. GRB 110319B Swift-XRT afterglow confirmation
  10. GRB 110319B BAT refined analysis
  11. GRB 110319B: Swift/UVOT Upper Limits
  12. GRB 110318B: Swift/UVOT Upper Limits
  13. GRB 110319B: GROND upper limits
  14. GRB 110319B: Swift-XRT afterglow candidate.
  15. GRB 110319B found in ground analysis of Swift-BAT data
  16. GRB 110319A: Swift/UVOT Detection
  17. GRB 110318B: GROND upper limits
  18. GRB 110319A: Enhanced Swift-XRT position
  19. GRB 110319A: Swift detection of a burst
  20. GRB 110318B: Enhanced Swift-XRT position
  21. GRB 110318B: Swift/UVOT Non-Detection of an Afterglow
  22. GRB 110318B: Swift detection of a burst
  23. GRB 110318A: Swift detection of a burst
  24. GRB 110315A: RTT150 optical observations
  25. GRB 110315A: Swift/UVOT Upper Limits
  26. GRB 110315A: Swift-BAT refined analysis
  27. GRB 110315A: Enhanced Swift-XRT position
  28. GRB 110315A: MASTER early optical observations
  29. GRB 110315A: Swift detection of a burst
  30. GRB110312A: MITSuME Okayama Optical upper limits
  31. GRB 110312A: RTT150 optical observations
  32. GRB 110312A: Swift/UVOT Upper Limits
  33. GRB 110312A: GROND Upper Limits
  34. GRB 110312A: Enhanced Swift-XRT position
  35. GRB 110312A: Swift detection of a burst
  36. GRB 110305A: REM detection of a possible NIR afterglow
  37. GRB110305A: MITSuME Ishigakijima Optical upper limits
  38. GRB 110305A: Swift/UVOT Upper Limits
  39. GRB 110305A: Enhanced Swift-XRT position
  40. GRB 110305A: GROND Detection of Optical Afterglow
  41. GRB 110305A: Swift detection of a burst
  42. GRB 110223A: optical upper limits
  43. GRB 110301A: Fermi GBM detection
  44. GRB101225A: early EVLA Observations of Christmas Burst
  45. Swift/UVOT observations of GRB110223A
  46. No IPN GRB detected in conjunction with candidate GRB 110215
  47. IBAS distribution of coordinates for low significance INTEGRAL GRB triggers
  48. Swift/UVOT observations of GRB110223b
  49. GRB 110223A : early optical limit by "Pi of the Sky"
  50. GRB 110223A: Enhanced Swift-XRT position
  51. GRB 110223B: Enhanced Swift-XRT position
  52. GRB 110223B: GROND Detection of Optical Afterglow Candidate
  53. GRB 110223A: Observations from BOOTES-2
  54. GRB 110223B: Swift detection of a burst
  55. GRB 110223A: Swift detection of a burst
  56. OT 110215: Further NIR observations from NOT of the GRB candidate
  57. GRB 110213B: Swift/UVOT observations
  58. Fermi GBM detection of an SGR-like burst
  59. Swift XRT and UVOT Observations of OT 110215
  60. OT 110215: NIR observations from NOT of GRB candidate
  61. GRB 110213A: optical observations in CrAO
  62. GRB 110213B: GROND observations of the optical/NIR afterglow
  63. OT 110215: possible GRB from 2MASS J00264184+8324093
  64. Swift/UVOT observations of GRB110210a.
  65. GRB 110210A: optical upper limit
  66. GRB 110213B: Possible Host Galaxy in SDSS Stripe 82 Imaging
  67. GRB 110210A: ROVOR Upper Limit
  68. GRB 110213B: P60 Optical Afterglow Candidate
  69. GRB110213A: RAPTOR Early Optical Peak and Plateau Measurements
  70. GRB 110212A: Swift XRT and UVOT observations
  71. GRB 110205A: Konkoly optical observations
  72. GRB 110213B: Swift XRT observation
  73. GRB 110213A: MITSuME Akeno Optical Observation
  74. Konus-Wind observation of GRB 110213B
  75. GRB110213A: MITSuME Okayama Optical Observation
  76. GRB 110213A: Swift/UVOT refined analysis
  77. GRB 110213A, Swift-BAT refined analysis
  78. GRB 110213A: optical observations
  79. GRB 110213A: Enhanced Swift-XRT position
  80. GRB110212A: MITSuME Okayama optical upper limits
  81. GRB 110213A: P60 Optical Afterglow Detection
  82. GRB 110213A: Swift detection of a burst with optical afterglow
  83. GRB 110212A: GRT Optical Observation
  84. GRB 110212A: SARA-N Optical Limits
  85. GRB110212A: BOOTES-2/TELMA optical limits
  86. GRB 110212A: ROTSE-III Optical Limits
  87. GRB 110212A: Swift detection of a burst
  88. GRB 110201A: Subaru/MOIRCS Ks-band photometry
  89. GRB 110205A: detection of optical linear polarization from CAHA
  90. GRB 110205A: Swift/BAT and Suzaku/WAM joint spectral analysis
  91. GRB 110210A: Enhanced Swift-XRT position
  92. GRB 110201A: optical observations
  93. GRB 110210A: Swift detection of a burst
  94. GRB 110208A: Magellan confirmation of the optical afterglow
  95. Fermi GBM detection of a burst from 1E 1841-045
  96. Swift/UVOT observations of GRB110208a
  97. GRB 110207A: Swift-XRT observations
  98. GRB 110208A: Enhanced Swift-XRT position
  99. GRB 110208A: Swift detection of a burst
  100. SGR-like outburst from the magnetar 1E 1841-04.5

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