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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"

28049 results found.

  1. GRB 070124: Suzaku WAM observation of the prompt emissions
  2. GRB 070125: UVOT Detection in Ultraviolet Filters
  3. GRB 070126, Swift-BAT refined analysis of a very faint burst
  4. GRB070125: Optical observation by Kanata
  5. GRB070124: Swift-XRT Observation
  6. Possible GRB 070126: Swift/UVOT Upper Limit
  7. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  8. GRB 070125: Xinglong TNT optical observations
  9. GRB 070125: Keck/LRIS Spectroscopy -- Evidence for a very low redshift
  10. GRB 070125: Lick 3m Spectroscopy
  11. GRB070125: Swift-XRT Refined Analysis
  12. GRB 070125: SARA detection in R
  13. GRB 070125: P60 Optical Afterglow Candidate
  14. GRB 070126?: Swift detection of a possible burst
  15. GRB070125 redshift request
  16. IPN localization of GRB070124 (short duration, hard spectrum)
  17. GRB 070110: Ep,i - Eiso correlation
  18. GRB 070107: Suzaku WAM observation of the prompt emission
  19. GRB070110: Swift XRT Team refined analysis
  20. GRB 070110, Swift-BAT refined analysis
  21. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  22. GRB 070110: Swift detection of a burst with a possible optical afterglow
  23. GRB 070107: Possible UVOT Afterglow
  24. GRB 070107, Swift-BAT refined analysis
  25. GRB 070107: Swift detection of a burst
  26. VLA observation of GRB 061222B
  27. VLA detection of GRB 061222A
  28. GRB070103: APO SPIcam i' and z' limits
  29. GRB070103: KPNO 4m+FLAMINGOS J limit
  30. GRB 070103: Swift/UVOT Upper limits
  31. GRB070103: Swift XRT refined analysis
  32. GRB 070103, Swift-BAT refined analysis
  33. GRB 070103: NOT observations
  34. GRB 070103: TAROT Calern observatory optical observations
  35. Retractions of previous Swift-BAT triggers
  36. erratum : SDSS Pre-burst Observations of GRB061126
  37. GRB 061210: Swift/XRT Astrometry Correction
  38. GRB 050826: MDM Redshift
  39. GRB 061222A: Confirmation of Gemini Afterglow Candidate
  40. GRB 061222A: Xinglong Optical Limit
  41. GRB 061222A: Gemini Afterglow Candidate
  42. GRB 061222B, Swift-BAT refined analysis
  43. GRB061222A Swift/UVOT: Upper Limits
  44. GRB 061222B: Swift/UVOT Upper limits
  45. GRB 061222B: Observation with the KANATA 1.5m telescope
  46. GRB 061222A: Observation with the KANATA 1.5m telescope
  47. GRB 061222B: BOOTES-IR optical observations
  48. GRB 061222B: SARA upper limit
  49. GRB 061217: Magellan host galaxy redshift
  50. GRB 061222A, Swift-BAT refined analysis
  51. GRB 061222B: REM NIR/optical observations
  52. GRB 061222B: TAROT La Silla observatory optical observations
  53. GRB 061222B: Swift detection of a burst
  54. GRB 061222b: optical afterglow
  55. GRB 061222A: Prompt ROTSE-III Optical Limits
  56. GRB 061222: Swift detection of a burst
  57. GRB 061218: TAROT La Silla observatory optical observations
  58. GRB 061217: TAROT Calern observatory optical observations
  59. GRB 061218: TORTOREM optical upper limits
  60. GRB 061218, Swift-BAT refined analysis
  61. GRB061217: VLT NIR observations
  62. GRB 061218, SMARTS optical/IR observations
  63. GRB 061218: REM prompt observations
  64. Swift triggers (#251863) on a possible burst
  65. GRB061217: Swift/UVOT refined analysis.
  66. GRB 061217: optical observations at Calar Alto
  67. GRB061217 - Swift/XRT refined analysis
  68. GRB 061217, Swift-BAT refined analysis
  69. GRB 061217: Magellan Observations
  70. GRB 061217: REM prompt observations
  71. GRB 061217: ROTSE-III Optical Limits
  72. GRB061210: Swift/UVOT observations
  73. GRB 061210: Swift XRT analysis - Possible counterparts
  74. GRB 061210: Gemini/GMOS Observations
  75. GRB 061126: Radio Observations
  76. GRB061210: Radio Observations
  77. GRB 061202: Suzaku WAM observation of the prompt emission
  78. GRB 061210, Swift-BAT refined analysis of the SHB
  79. Optical Afterglow observations of GRB 061126
  80. GRB 060926: MASTER: discovery of the optical flare
  81. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  82. GRB 061202: TORTOREM optical upper limits
  83. GRB 061201: VLT optical decay
  84. GRB 061201: SOAR Confirmation of Candidate Afterglow
  85. GRB061202: FRAM early follow-up limit
  86. GRB061202 optical limit by "Pi of the Sky"
  87. GRB061202: optical/NIR observations with REM
  88. GRB061202: Swift/UVOT Upper Limits
  89. GRB 061202, Swift-BAT refined analysis
  90. GRB 061202: Swift detection of a burst
  91. GRB 061201: VLT optical observations
  92. GRB 061201: Initial UVOT Observations
  93. GRB 061201, Swift-BAT refined analysis of the SHB
  94. GRB 061201: Swift detection of a short hard burst
  95. INT+WFC observations of GRB 061126
  96. Swift XRT on-board boresight update
  97. GRB 061126: optical observation
  98. GRB 061126: Tautenburg afterglow observations
  99. GRB061126: Optical afterglow observations from MIRO
  100. GRB061126: Optical afterglow observations from MIRO

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