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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"

28059 results found.

  1. GRB 070129, Swift-BAT refined analysis of a particularly long
  2. GRB 070129: Xinglong TNT optical Upper Limit
  3. GRB 070129: Swift-XRT Refined Analysis
  4. GRB 070129: VLT observations
  5. GRB 070125: An IR Point Source and an Apparent Host Galaxy
  6. GRB 070129: Swift detection of a burst
  7. GRB 070126: Swift/UVOT refined analysis
  8. GRB 070125: MITSuME Okayama optical observation
  9. GRB 070125: optical observations
  10. GRB 070126: VLT observations
  11. GRB 070124: Suzaku WAM observation of the prompt emissions
  12. GRB 070125: UVOT Detection in Ultraviolet Filters
  13. GRB 070126, Swift-BAT refined analysis of a very faint burst
  14. GRB070125: Optical observation by Kanata
  15. GRB070124: Swift-XRT Observation
  16. Possible GRB 070126: Swift/UVOT Upper Limit
  17. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  18. GRB 070125: Xinglong TNT optical observations
  19. GRB 070125: Keck/LRIS Spectroscopy -- Evidence for a very low redshift
  20. GRB 070125: Lick 3m Spectroscopy
  21. GRB070125: Swift-XRT Refined Analysis
  22. GRB 070125: SARA detection in R
  23. GRB 070125: P60 Optical Afterglow Candidate
  24. GRB 070126?: Swift detection of a possible burst
  25. GRB070125 redshift request
  26. IPN localization of GRB070124 (short duration, hard spectrum)
  27. GRB 070110: Ep,i - Eiso correlation
  28. GRB 070107: Suzaku WAM observation of the prompt emission
  29. GRB070110: Swift XRT Team refined analysis
  30. GRB 070110, Swift-BAT refined analysis
  31. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  32. GRB 070110: Swift detection of a burst with a possible optical afterglow
  33. GRB 070107: Possible UVOT Afterglow
  34. GRB 070107, Swift-BAT refined analysis
  35. GRB 070107: Swift detection of a burst
  36. VLA observation of GRB 061222B
  37. VLA detection of GRB 061222A
  38. GRB070103: APO SPIcam i' and z' limits
  39. GRB070103: KPNO 4m+FLAMINGOS J limit
  40. GRB 070103: Swift/UVOT Upper limits
  41. GRB070103: Swift XRT refined analysis
  42. GRB 070103, Swift-BAT refined analysis
  43. GRB 070103: NOT observations
  44. GRB 070103: TAROT Calern observatory optical observations
  45. Retractions of previous Swift-BAT triggers
  46. erratum : SDSS Pre-burst Observations of GRB061126
  47. GRB 061210: Swift/XRT Astrometry Correction
  48. GRB 050826: MDM Redshift
  49. GRB 061222A: Confirmation of Gemini Afterglow Candidate
  50. GRB 061222A: Xinglong Optical Limit
  51. GRB 061222A: Gemini Afterglow Candidate
  52. GRB 061222B, Swift-BAT refined analysis
  53. GRB061222A Swift/UVOT: Upper Limits
  54. GRB 061222B: Swift/UVOT Upper limits
  55. GRB 061222B: Observation with the KANATA 1.5m telescope
  56. GRB 061222A: Observation with the KANATA 1.5m telescope
  57. GRB 061222B: BOOTES-IR optical observations
  58. GRB 061222B: SARA upper limit
  59. GRB 061217: Magellan host galaxy redshift
  60. GRB 061222A, Swift-BAT refined analysis
  61. GRB 061222B: REM NIR/optical observations
  62. GRB 061222B: TAROT La Silla observatory optical observations
  63. GRB 061222B: Swift detection of a burst
  64. GRB 061222b: optical afterglow
  65. GRB 061222A: Prompt ROTSE-III Optical Limits
  66. GRB 061222: Swift detection of a burst
  67. GRB 061218: TAROT La Silla observatory optical observations
  68. GRB 061217: TAROT Calern observatory optical observations
  69. GRB 061218: TORTOREM optical upper limits
  70. GRB 061218, Swift-BAT refined analysis
  71. GRB061217: VLT NIR observations
  72. GRB 061218, SMARTS optical/IR observations
  73. GRB 061218: REM prompt observations
  74. Swift triggers (#251863) on a possible burst
  75. GRB061217: Swift/UVOT refined analysis.
  76. GRB 061217: optical observations at Calar Alto
  77. GRB061217 - Swift/XRT refined analysis
  78. GRB 061217, Swift-BAT refined analysis
  79. GRB 061217: Magellan Observations
  80. GRB 061217: REM prompt observations
  81. GRB 061217: ROTSE-III Optical Limits
  82. GRB061210: Swift/UVOT observations
  83. GRB 061210: Swift XRT analysis - Possible counterparts
  84. GRB 061210: Gemini/GMOS Observations
  85. GRB 061126: Radio Observations
  86. GRB061210: Radio Observations
  87. GRB 061202: Suzaku WAM observation of the prompt emission
  88. GRB 061210, Swift-BAT refined analysis of the SHB
  89. Optical Afterglow observations of GRB 061126
  90. GRB 060926: MASTER: discovery of the optical flare
  91. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  92. GRB 061202: TORTOREM optical upper limits
  93. GRB 061201: VLT optical decay
  94. GRB 061201: SOAR Confirmation of Candidate Afterglow
  95. GRB061202: FRAM early follow-up limit
  96. GRB061202 optical limit by "Pi of the Sky"
  97. GRB061202: optical/NIR observations with REM
  98. GRB061202: Swift/UVOT Upper Limits
  99. GRB 061202, Swift-BAT refined analysis
  100. GRB 061202: Swift detection of a burst

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