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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"

16110 results found.

  1. GRB070208: Absorption and emission redshift from Gemini
  2. GRB 070208: MDM Optical Decay
  3. GRB 070208: Early IR detection and afterglow astrometry
  4. GRB 070208: ROTSE-III Optical Limits
  5. GRB 070208: MDM Observations
  6. GRB 070125 detection with CARMA
  7. GRB 070125: Redshift z>~1.54 from Gemini Afterglow Spectrum
  8. GRB 070125: further AAVSO optical observations
  9. GRB 070125: optical observation
  10. GRB 070125: WSRT Radio Detection
  11. GRB070129: MITSuME optical observation
  12. GRB061217: MAGIC telescope GeV observation
  13. GRB 070129, Swift-BAT refined analysis of a particularly long
  14. GRB 070129: Xinglong TNT optical Upper Limit
  15. GRB 070125: further AAVSO optical observations
  16. GRB 070125: MITSuME Okayama optical observation
  17. GRB 070125: AAVSO optical observations
  18. GRB 070125: optical observations
  19. GRB 070125: WSRT Radio Observations
  20. GRB070125: Optical observation by Kanata
  21. Possible GRB 070126: Swift/UVOT Upper Limit
  22. GRB 070125: UVOT Observations of a Fading Optical Afterglow
  23. GRB 070125: Xinglong TNT optical observations
  24. GRB 070125: Continued P60 Observations
  25. GRB070125: Swift-XRT Refined Analysis
  26. GRB 070125: P60 Optical Afterglow Candidate
  27. GRB 070110: optical break
  28. GRB 070110: Continued Detection and Request for Ground Followup
  29. GRB 070110 declared a "Burst of Interest" by Swift team
  30. GRB 070110: VLT absorption redshift
  31. GRB 070110: UVOT Observations of a Candidate Afterglow
  32. GRB070107 Swift/UVOT Observations of a Fading Optical Afterglow
  33. GRB 070110: Swift detection of a burst with a possible optical afterglow
  34. GRB070107: Swift/XRT refined analysis
  35. GRB 061201: Nearby Galaxy Cluster Abell 995 is at z=0.0865
  36. GRB 070103: TAROT Calern observatory optical observations
  37. GRB061222a: optical observations
  38. GRB 061210: Swift/XRT Astrometry Correction
  39. GRB 050826: MDM Redshift
  40. GRB 061222B: TAROT La Silla observatory early optical observations
  41. GRB 061218: TAROT La Silla observatory early optical observations
  42. GRB 061222A: MITSuME Akeno optical upper limits
  43. GRB 061222B: MITSuME Akeno optical upper limits
  44. GRB 061222A: Xinglong Optical Limit
  45. GRB061222A Swift/UVOT: Upper Limits
  46. GRB 061222B: Observation with the KANATA 1.5m telescope
  47. GRB061222B: Swift-XRT Refined Analysis
  48. GRB 061222A: Observation with the KANATA 1.5m telescope
  49. GRB 061222B: BOOTES-IR optical observations
  50. GRB 061222B: REM NIR/optical observations
  51. GRB 061222b, SMARTS optical/IR afterglow observations
  52. GRB 061222B: TAROT La Silla observatory optical observations
  53. GRB 061222b: optical afterglow
  54. GRB 061222A: Prompt ROTSE-III Optical Limits
  55. GRB 061217: Astrometry-Corrected XRT Position
  56. GRB 061201: Magellan redshift of nearby galaxy
  57. GRB 061217, Candidate host galaxy
  58. GRB 061218: TAROT La Silla observatory optical observations
  59. GRB 061217: TAROT Calern observatory optical observations
  60. GRB 061218: TORTOREM optical upper limits
  61. GRB 061218, SMARTS optical/IR observations
  62. GRB 061218: REM prompt observations
  63. GRB 061217, SMARTS optical observations
  64. GRB061217: Swift/UVOT refined analysis.
  65. GRB 061217: optical observations at Calar Alto
  66. GRB 061217: REM prompt observations
  67. GRB 061217: ROTSE-III Optical Limits
  68. GRB 061210: MDM Follow-up Observation
  69. GRB061210: Swift/UVOT observations
  70. GRB 061210: Optical sources near XRT positions
  71. GRB 061210 : Faulkes North Telescope optical limit
  72. GRB 061214(?): ROTSE-III Optical Limits
  73. GRB 061213: MASTER-VWF-Kislovodsk optical candidate
  74. GRB061201, VLT optical decay: correction
  75. Optical Afterglow observations of GRB 061126
  76. GRB061126: optical observations
  77. GRB 060926: MASTER: discovery of the optical flare
  78. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  79. GRB 061202: TORTOREM optical upper limits
  80. GRB 061201: VLT optical decay
  81. GRB061126 : NMSU 1.0m observations
  82. GRB061202 optical limit by "Pi of the Sky"
  83. GRB061202: optical/NIR observations with REM
  84. GRB 061201: Swift XRT Team refined analysis
  85. GRB 061201: VLT optical observations
  86. GRB 061201: Initial UVOT Observations
  87. GRB 061122: GETS observation
  88. GRB 061121, SMARTS optical/IR observations
  89. INT+WFC observations of GRB 061126
  90. GRB 061121: Second Epoch ATCA Radio Observations
  91. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  92. GRB 061121: ATCA & WSRT Radio Observations
  93. GRB061121: optical observations
  94. GRB 061126: Early Super-LOTIS Observations
  95. GRB 061126: optical observation
  96. GRB061126: Optical afterglow observations from MIRO
  97. GRB061126: Optical afterglow observations from MIRO
  98. GRB 061126: Swift/UVOT Observations
  99. GRB 061126: Early Detection of the IR Afterglow
  100. GRB 061126: Faulkes Telescope North Optical Observations

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