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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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 080122 : Suzaku WAM observation of the prompt emission
  2. GRB 080121: Swift/UVOT upper limits
  3. SNe 2008D and 2007uy: Chandra Detections
  4. GRB 080121 position was incorrect
  5. GRB 080121: Enhanced Swift-XRT position
  6. Two non-burst Swift SubThreshold triggers
  7. Transient 080109/SN 2008D: Spectroscopic Evolution and Re-Classification
  8. IPN triangulation of GRB080122
  9. GRB 080121: Nearby SDSS galaxies
  10. GRB 080121: Swift-BAT detection of a very weak, short burst
  11. GRB 080123: Swift-XRT refined analysis
  12. GRB 080123: Swift/UVOT refined analysis
  13. X-ray transient in NGC 2770: RTT150 optical observations
  14. GRB 080123, Swift-BAT refined analysis
  15. GRB 080123: Enhanced Swift-XRT position
  16. GRB 080123: Swift detection of a short burst
  17. GRB 080120: GROND confirmation of the optical afterglow
  18. XRF 080109 / SN 2008D: GMRT radio observation at 1280 MHz
  19. VLA radio upper limit on GRB 080120
  20. GRB 080120: Swift-XRT refined analysis
  21. UVOT detection of GRB080120
  22. GRB 080120: GROND detection
  23. GRB 080120 : Planned XMM-Newton observation
  24. GRB080120: Swift XRT position
  25. GRB 080120: a long GRB detected by INTEGRAL
  26. XRF 080109 / SN 2008D: 1.4 GHz WSRT Radio Observations
  27. Transient in NGC2770 / SN2008D: Metallicity of nearby HII regions
  28. Transient XRF 080109 / SN 2008D: Mount Abu NIR observations
  29. XRF 080109 / SN 2008D: WSRT Radio Detection
  30. Transient 080109/ SN 2008D, metallicity of the host galaxy
  31. Transient 080109/ SN 2008D, IR Spectrum
  32. XRF 080109 / SN 2008D: optical observations
  33. NGC 2770B has the same redshift as NGC 2770
  34. Swift UVOT Monitoring of the SN 2008D Brightening (Transient in NGC 2770)
  35. XRF 080109 / SN 2008D: spectroscopic evolution
  36. XRF 080109 / SN 2008D: UKIRT JHK imaging
  37. optical observations, XRT in NGC 2770
  38. XRF 080109/SN 2008D: PROMPT Optical Imaging
  39. Gemini-South observations of XRF 080109 / SN 2008D
  40. Swift observations of the X-ray transient in NGC 2770 (aka SN2008D)
  41. Discovery of Radio Emission from Transient in NGC 2770
  42. XRF 080109 in NGC2770: NIR observations at TNG
  43. XRB 080109/SN 2008D: Early decline in brightness and change in colors
  44. XRB 080109/SN 2008D:PAIRITEL NIR observations and t_0 from Swift
  45. XRF 080109 in NGC2770: Detectable Superluminal Motion
  46. Detailed Spectroscopic ID of SN 2008D (Transient in NGC 2770)
  47. XRF in NGC 2770: Search for X-ray periodicity
  48. Spectroscopic classification of SN 2008D (Transient in NGC 2770)
  49. Refined Swift-XRT analysis of the transient in NGC 2770
  50. Transient in NGC 2770: spectroscopic evidence for a SN
  51. Refined Swift UVOT Analysis of SN 2008D (Transient in NGC 2770)
  52. Opticall follow-ups for the X-ray transient in NGC 2770
  53. X-ray transient in NGC 2770: Optical observations with Astrotel-Caucasus
  54. Optical Spectroscopy of the Transient in NGC 2770
  55. Swift UVOT Observations of the X-ray transient in NGC 2770
  56. Early OT detection of XRF in NGC 2770 in Asiago frames
  57. Bright X-ray transient / possible XRF in NGC 2770: TNG R imaging
  58. Possible XRF in NGC 2770 - NOT observations of the optical counterpart
  59. Bright X-ray Transient (a XRF? ) in NGC 2770 - A SN optical counterpart?
  60. Bright X-ray Transient in NGC 2770 - A low-luminosity XRF?
  61. GRB 071227: Suzaku WAM observation of the prompt emission
  62. GRB 071227: optical afterglow
  63. Further Swift-BAT analysis of GRB 071227
  64. Konus-Wind observation of GRB 071227
  65. GRB 071227: Magellan redshift confirmation
  66. GRB 071227: Swift-XRT refined analysis
  67. GRB 071227: VLT probable redshift of the candidate host galaxy
  68. GRB 071227: Magellan observations
  69. GRB071227: Swift/UVOT refined analysis
  70. GRB 071227: REM NIR and Optical observations
  71. Swift-BAT refined analysis of short GRB 071227
  72. GRB 071227: Swift detection of a burst
  73. GRB071020: optical observations
  74. GRB 070429B: Possible UVOT Detection of an Optical Afterglow
  75. Swift-BAT trigger 298308 is not a GRB
  76. GRB 071208?: Swift detection of a possible burst
  77. IBAS Alert #4772 in not a GRB
  78. GRB 071125: Suzaku WAM observation of the prompt emission
  79. GRB 070429B: Probable host galaxy and redshift
  80. GRB 071129, Swift-BAT refined analysis
  81. GRB 071129: Swift detection of a burst
  82. Konus-Wind and Konus-A observations of GRB 071125
  83. IPN triangulation of very bright GRB 071125
  84. GRB 071112C: Optical/NIR observations
  85. Disregard the "GRB 071126" position
  86. GRB 071126: Enhanced Swift-XRT position
  87. VLA radio detection of GRB 071122
  88. GRB071122: Swift/UVOT Observations
  89. GRB071104: NIR Afterglow Candidate at TNG
  90. GRB 071122: MASTER optical observation
  91. GRB 071122, Swift-BAT refined analysis
  92. GRB 071122 Swift XRT position update sent in error.
  93. GRB 071122 Swift-XRT refined analysis
  94. GRB 071122: Corrected P60 Coordinates
  95. GRB071122: Gemini Absorption redshift
  96. GRB 071122: P60 Optical Afterglow Candidate
  97. GRB 071122: ROTSE-III Optical Limits
  98. GRB 071122: Swift detection of a burst
  99. GRB 071118: P60 Observations
  100. GRB071118 MITSuME OAO optical observation

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