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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"
  1. GRB 080319A SDSS Pre-Burst Observations
  2. Swift-BAT trigger 306829 is IGR J16479-4514
  3. GRB080319B - SDSS Pre-Burst Observations
  4. GRB 080319B: RAPTOR observations of a naked eye burst
  5. GRB 080319A: Swift-XRT Team Refined Analysis
  6. GRB 080319B, Swift-BAT refined analysis
  7. GRB080319B: Prompt PROMPT Detections
  8. GRB 080319C: Swift-XRT Team Refined Analysis
  9. GRB 080319B: Swift-XRT Team Refined Analysis
  10. GRB 080319D: Swift/UVOT Refined Analysis of the Fading Optical Afterglow Candidate
  11. GRB 080319C: AGILE-MCAL observation of the prompt emission
  12. GRB 080319B: Hobby-Eberly Telescope Spectroscopy
  13. GRB 080319D: MASTER-VWF-Kislovodsk optical observation
  14. GRB 080319C: MASTER-VWF-Kislovodsk optical observation
  15. GRB 080319D: Swift detection of a burst with a possible optical afterglow
  16. GRB 080319B: TORTORA synchronous observation
  17. VLT/UVES redshift of GRB 080319B from FeII fine-structure lines
  18. GRB 080319A/B/C: INTEGRAL SPI-ACS light curves available
  19. GRB 080319B: Enhanced Swift-XRT position
  20. GRB 080319A: Enhanced Swift-XRT position
  21. GRB 080319A, Swift-BAT refined analysis
  22. GRB 080319B: REM early data
  23. GRB 080319b light curve by Pi-of-the-Sky
  24. VLT/UVES redshift of GRB 080319B
  25. GRB 080319C: Early Super-LOTIS Observations
  26. GRB 080319C: Swift detection of a burst with an optical afterglow
  27. GRB 080319C: KAIT OA candidate
  28. GRB 080319A: REM observations
  29. GRB 080319b prompt optical observation by Pi-of-the-Sky
  30. GRB 080319B: Change in power law decay index
  31. GRB 080319B: Gemini-South Spectroscopy
  32. GRB 080319A: optical observations at the NOT
  33. GRB0 080319B : LOAO optical observation
  34. GRB 080319b: Early IR Imaging from PAIRITEL
  35. GRB080319B Liverpool Telescope optical afterglow candidate
  36. GRB 080319B: Super-LOTIS Detection of a Bright OT
  37. GRB 080319B: REM observations
  38. GRB 080319B: KAIT OA
  39. GRB080319A: P60 Optical Afterglow Observations
  40. GRB 080319B: UVOT Position
  41. GRB 080319B: Swift detection of an intense burst with a bright optical counterpart
  42. GRB 080319A: Swift detection of a burst
  43. Swift Trigger 306745 is not a GRB
  44. Swift Trigger 306616 is not a GRB
  45. GRB080310, LBT and MDM photometry
  46. GRB080315: Bok Optical Observations
  47. Swift/UVOT observations of GRB 080315
  48. Swift trigger 306323: Swift-BAT/XRT refined analysis
  49. SAX J1818.6-1703: Swift detection (trigger 306379)
  50. GRB 080315: Optical observations
  51. GRB 080315: TAROT Calern observatory optical observations
  52. GRB 080315: Swift detection of a possible burst
  53. GRB080310 : Lulin Optical observations
  54. GRB080310, unusual slow decay in the optical
  55. GRB 080310: GAO 150cm telescope Optical Observation
  56. GRB080310 : Optical observations by LOAO and Lulin
  57. GRB 080310: ROTSE-III Observations of Optical Counterpart
  58. GRB080310: Optical observation by MITSuME telescope
  59. GRB080310, optical observations with the LBT
  60. GRB 080307: GAO 150cm telescope Optical Observation
  61. GRB 080229A: GAO 150cm telescope Optical Observation
  62. GRB 080310: PAIRITEL detection and PAIRITEL+KAIT+UVOT SED
  63. GRB 080307: NIR upper limit
  64. GRB 080229: NIR upper limit
  65. GRB 080310: early RAPTOR multicolor observations
  66. GRB 080310, Swift-BAT refined analysis
  67. GRB080210: optical observations
  68. GRB080307: optical upper limit
  69. GRB 080310: Swift-XRT refined analysis
  70. GRB 080310: Swift/UVOT Refined Analysis
  71. GRB 080310: Redshift from Keck/DEIMOS Spectra
  72. GRB 080310 - SDSS Pre-Burst Observations
  73. GRB080310 : Lulin optical observation
  74. GRB 080310: Enhanced Swift-XRT position
  75. GRB 080310: RRM optical photometry with the VLT
  76. GRB080310, detection of break in optical
  77. GRB 080310: VLT/UVES spectroscopy
  78. GRB080310, optical observations with LBT
  79. GRB 080310: Magellan redshift revision
  80. GRB 080310: Lick/Kast Spectroscopy
  81. GRB080310: Super-LOTIS suggestion of brightening
  82. GRB 080310, SMARTS optical/IR afterglow observations
  83. GRB 080310: REM observations
  84. GRB 080310: Magellan redshift
  85. GRB 080310 afterglow candidate (correction to UT time)
  86. GRB 080310: Swift detection of a burst with optical afterglow
  87. GRB 080310 afterglow candidate
  88. GRB080229, optical upper limit (Correction)
  89. GRB080307, optical upper limit
  90. GRB080307 BOAO optical afterglow observation - detection of a possible OT
  91. GRB080229, optical upper limit
  92. GRB 080307: Swift-XRT Team refined analysis
  93. GRB 080307: Swift/UVOT Upper Limits
  94. GRB 080307: Early RAPTOR Limits
  95. GRB 080307, Swift-BAT refined analysis
  96. GRB080307 - SDSS Pre-Burst Observations
  97. GRB 080307: TNT optical observation
  98. GRB080307: Optical upper limits
  99. GRB 080307: Gemini-N i-band observations - candidate afterglow
  100. GRB 080307: BOAO imaging - retraction and new limit

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