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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"

28058 results found.

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

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