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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').
  1. GRB 080319B: REM early data
  2. GRB 080319b light curve by Pi-of-the-Sky
  3. VLT/UVES redshift of GRB 080319B
  4. GRB 080319C: Early Super-LOTIS Observations
  5. GRB 080319C: Swift detection of a burst with an optical afterglow
  6. GRB 080319C: KAIT OA candidate
  7. GRB 080319A: REM observations
  8. GRB 080319b prompt optical observation by Pi-of-the-Sky
  9. GRB 080319B: Change in power law decay index
  10. GRB 080319B: Gemini-South Spectroscopy
  11. GRB 080319A: optical observations at the NOT
  12. GRB0 080319B : LOAO optical observation
  13. GRB 080319b: Early IR Imaging from PAIRITEL
  14. GRB080319B Liverpool Telescope optical afterglow candidate
  15. GRB 080319B: Super-LOTIS Detection of a Bright OT
  16. GRB 080319B: REM observations
  17. GRB 080319B: KAIT OA
  18. GRB080319A: P60 Optical Afterglow Observations
  19. GRB 080319B: UVOT Position
  20. GRB 080319B: Swift detection of an intense burst with a bright optical counterpart
  21. GRB 080319A: Swift detection of a burst
  22. Swift Trigger 306745 is not a GRB
  23. Swift Trigger 306616 is not a GRB
  24. GRB080310, LBT and MDM photometry
  25. GRB080315: Bok Optical Observations
  26. Swift/UVOT observations of GRB 080315
  27. Swift trigger 306323: Swift-BAT/XRT refined analysis
  28. SAX J1818.6-1703: Swift detection (trigger 306379)
  29. GRB 080315: Optical observations
  30. GRB 080315: TAROT Calern observatory optical observations
  31. GRB 080315: Swift detection of a possible burst
  32. GRB080310 : Lulin Optical observations
  33. GRB080310, unusual slow decay in the optical
  34. GRB 080310: GAO 150cm telescope Optical Observation
  35. GRB080310 : Optical observations by LOAO and Lulin
  36. GRB 080310: ROTSE-III Observations of Optical Counterpart
  37. GRB080310: Optical observation by MITSuME telescope
  38. GRB080310, optical observations with the LBT
  39. GRB 080307: GAO 150cm telescope Optical Observation
  40. GRB 080229A: GAO 150cm telescope Optical Observation
  41. GRB 080310: PAIRITEL detection and PAIRITEL+KAIT+UVOT SED
  42. GRB 080307: NIR upper limit
  43. GRB 080229: NIR upper limit
  44. GRB 080310: early RAPTOR multicolor observations
  45. GRB 080310, Swift-BAT refined analysis
  46. GRB080210: optical observations
  47. GRB080307: optical upper limit
  48. GRB 080310: Swift-XRT refined analysis
  49. GRB 080310: Swift/UVOT Refined Analysis
  50. GRB 080310: Redshift from Keck/DEIMOS Spectra
  51. GRB 080310 - SDSS Pre-Burst Observations
  52. GRB080310 : Lulin optical observation
  53. GRB 080310: Enhanced Swift-XRT position
  54. GRB 080310: RRM optical photometry with the VLT
  55. GRB080310, detection of break in optical
  56. GRB 080310: VLT/UVES spectroscopy
  57. GRB080310, optical observations with LBT
  58. GRB 080310: Magellan redshift revision
  59. GRB 080310: Lick/Kast Spectroscopy
  60. GRB080310: Super-LOTIS suggestion of brightening
  61. GRB 080310, SMARTS optical/IR afterglow observations
  62. GRB 080310: REM observations
  63. GRB 080310: Magellan redshift
  64. GRB 080310 afterglow candidate (correction to UT time)
  65. GRB 080310: Swift detection of a burst with optical afterglow
  66. GRB 080310 afterglow candidate
  67. GRB080229, optical upper limit (Correction)
  68. GRB080307, optical upper limit
  69. GRB080307 BOAO optical afterglow observation - detection of a possible OT
  70. GRB080229, optical upper limit
  71. GRB 080307: Swift-XRT Team refined analysis
  72. GRB 080307: Swift/UVOT Upper Limits
  73. GRB 080307: Early RAPTOR Limits
  74. GRB 080307, Swift-BAT refined analysis
  75. GRB080307 - SDSS Pre-Burst Observations
  76. GRB 080307: TNT optical observation
  77. GRB080307: Optical upper limits
  78. GRB 080307: Gemini-N i-band observations - candidate afterglow
  79. GRB 080307: BOAO imaging - retraction and new limit
  80. GRB 080307: retraction of UVOT candidate
  81. GRB 080307: Enhanced Swift-XRT position
  82. GRB 080307, Preliminary Swift-BAT refined analysis
  83. GRB 080307 : BOAO optical afterglow observation
  84. GRB 080307: Optical observation with DMC/KANATA
  85. GRB 080307: Swift detection of a burst
  86. VLA possible radio detection of GRB 080229
  87. GRB 080303: Swift/UVOT follow-up of afterglow detection
  88. GRB 080303, Swift-BAT refined analysis
  89. GRB 080303: Rapid PROMPT Detections
  90. GRB080303: Swift XRT refined analysis
  91. GRB 080303: Enhanced Swift-XRT position
  92. Swift UVOT observations of GRB080229B
  93. GRB080229B: Swift XRT afterglow observation
  94. GRB 080303A: Faulkes Telescope South optical afterglow observations
  95. GRB 080303
  96. GRB 080303: Swift detection of a burst with optical afterglow
  97. GRB 080303: REM NIR afterglow candidate
  98. GRB 080303A: ROTSE-III Optical Limits
  99. GRB 080229: I-band observations from OSN
  100. GRB 080229: VLT NIR observations

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