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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"

41637 results found.

  1. GRB 070309: variability of the XRT afterglow candidate
  2. GRB 070311: MDM Optical Follow-up
  3. GRB 070311: RAPTOR Detection of Optical Emission
  4. GRB070311: FRAM early follow-up limit
  5. GRB 070311: MDM Optical Detection
  6. GRB 070311: MITSuME Okayama Optical Observation
  7. GRB 070311: Swift-XRT refined analysis
  8. GRB 070311: PAIRITEL confirmation of variability of REM candidate
  9. GRB 070311: REM candidate afterglow
  10. GRB 070311: a long GRB detected by INTEGRAL
  11. GRB060901: Candidate optical afterglow
  12. GRB070309: Swift/XRT possible afterglow detection
  13. GRB 070125: Chandra X-ray Confirmation of Jet Break
  14. GRB 070309: Swift/UVOT Upper Limits
  15. GRB 070309: A long GRB detected by INTEGRAL
  16. GRB 070125: X-ray light curve analysis
  17. VLA observation of GRB 070306
  18. IBAS Alert 4162: Not a GRB
  19. GRB 070306: NOT observations
  20. GRB 070306 Swift/UVOT refined analysis
  21. GRB070306: confirmation of near infrared afterglow
  22. GRB 070306: ART-3 early optical and near infrared constraints
  23. GRB 070306: IR observations and candidate afterglow
  24. GRB 070306, Swift-BAT refined analysis
  25. GRB 070306: XRT Team Refined Analysis
  26. GRB 070306: Optical and IR observations with KANATA
  27. GRB070306 - SDSS Pre-burst Observations
  28. GRB 070306: Swift detection of a burst
  29. GRB 070223: NIR observations at WHT
  30. GRB070227: Swift-XRT refined analysis
  31. GRB 060605 new redshift
  32. GRB 070125, deep late-time optical observation
  33. VLA observation of GRB 070224
  34. GRB 070227: optical observations
  35. GRB 070223: Optical Observations
  36. GRB 070227: optical observations
  37. GRB 070227: Swift/UVOT Upper Limits
  38. GRB 070227: TAROT La Silla observatory optical observations
  39. GRB 070227, Swift-BAT refined analysis
  40. GRB070227: possible X-ray afterglow detection
  41. GRB 070227: Swift detection of a burst in ground analysis
  42. GRB 920925C: optical afterglow candidate
  43. GRB 070224: Optical afterglow confirmation
  44. IBAS Alert n. 4144: not a GRB
  45. GRB 070224: Swift/UVOT Upper Limits
  46. GRB070224: Swift-XRT Astrometrically Corrected Position
  47. VLA observation of GRB 070223
  48. VLA observation of GRB 070220
  49. GRB070224: Magellan Imaging Observations
  50. GRB 070224: WHT K-band imaging
  51. GRB070224: Gemini Imaging Observations
  52. GRB 070224: SARA upper limit
  53. GRB070224: Swift-XRT Refined Analysis
  54. GRB 070224: optical afterglow candidate
  55. GRB 070224, Swift-BAT refined analysis
  56. GRB 070224: MASTER-Net refind analysis
  57. GRB 070224: MASTER-VWF-Kislovodsk observations
  58. GRB 070224: MASTER observations
  59. GRB 070224: Swift detection of a burst
  60. RHESSI Spectrum of GRB070220
  61. GRB070223: Swift/UVOT refined analysis
  62. GRB 070223: Optical-IR observation with KANATA
  63. GRB 070223, Swift-BAT refined analysis
  64. GRB070223: MASTER-VWF-Kislovodsk observations
  65. GRB 070223: Swift-XRT Refined Analysis
  66. GRB070223 - SDSS Pre-Burst Observations
  67. GRB 070223: Liverpool Telescope Possible Afterglow Candidate
  68. GRB 070223: MDM Observations
  69. GRB070223: Swift burst
  70. Konus-Wind and Konus-A observations of GRB 070220
  71. GRB 070220: MITSuME Okayama Optical Observation
  72. GRB 070220: ART-3 Optical and NIR limits
  73. Swift/UVOT refined analysis of GRB070220
  74. GRB 070209: Swift XRT refined analysis
  75. GRB 070220: Swift-XRT Refined Analysis
  76. GRB 070220: Observation with the KANATA 1.5m telescope
  77. GRB 070219: Gemini Observations
  78. GRB 070220: Swift detection of a burst
  79. GRB070219: MASTER-VWF-Kislovodsk observations
  80. GRB 070219: XRT Refined Analysis
  81. GRB 070219: Swift/UVOT Upper limits
  82. GRB 070219: I-band observations
  83. GRB 070219: optical TNG observations
  84. GRB 070219: ROTSE-III Optical Limits
  85. GRB070219 - SDSS Pre-Burst Observations
  86. GRB 070219: Swift detection of a burst
  87. IPN triangulation of GRB070201 (refined error box using MESSENGER data)
  88. GRB 070125 observations with the GMRT
  89. GRB 070209: Redshift of a galaxy in the error circle of XRT source
  90. Swift-BAT trigger 260304 is NOT a burst or transient
  91. GRB 060927: PROMPT Observations
  92. GRB 070125: Break in Optical Decay
  93. GRB 070209: Swift XRT analysis
  94. GRB 070201: clarification on localization and Konus-Wind spectra
  95. GRB070208: optical observations
  96. GRB 070201: IPN constraints and nearby galaxies
  97. GRB 070201: Proximity of IPN annulus to M31
  98. GRB 070208: MARGE Optical Observations
  99. IPN localization of very bright long hard GRB 070207
  100. IPN localization of very intense short GRB 070201

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