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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"

32506 results found.

  1. GRB 080130: Swift-BAT refined analysis
  2. GRB 080130: further Swift XRT observations confirm fading source
  3. GRB 080129: Swift/UVOT Refined Upper Limits
  4. Swift/UVOT observations of GRB080130
  5. GRB 080130: REM NIR observations
  6. GRB 080130(?): Swift XRT observation
  7. GRB 080130?: Detection of a possible burst by BATSS
  8. GRB 080129: Optical observations from OSN
  9. GRB 080129: Swift-XRT refined analysis
  10. X-ray transient in NGC 2770: RTT150 optical observations
  11. GRB 080129: KAIT optical limits
  12. GRB 080123: Early afterglow detection with BATSS (BAT Slew Survey)
  13. GRB 080129, Swift-BAT refined analysis
  14. GRB 080129: Gemini-South photometry
  15. GRB 080129: GROND detection in all bands, and fading
  16. GRB 080129: GROND detection of the optical/NIR afterglow, and fading
  17. GRB 080129: Gemini-South Imaging Observations
  18. GRB 080129: Swift XRT position
  19. GRB 080129 (?): UVOT Upper Limits
  20. A new website of high-level data products for Swift GRBs
  21. GRB 080121: Upper limit on X-ray afterglow
  22. GRB 080123 : Suzaku WAM observation of the prompt emission
  23. Swift trigger(=301779) is not a GRB
  24. Transient 080109/SN 2008D: Spectroscopic Evolution
  25. Konus-Wind observation of GRB 080122
  26. GRB 080122 : Suzaku WAM observation of the prompt emission
  27. GRB 080121: Swift/UVOT upper limits
  28. SNe 2008D and 2007uy: Chandra Detections
  29. GRB 080121 position was incorrect
  30. Two non-burst Swift SubThreshold triggers
  31. Transient 080109/SN 2008D: Spectroscopic Evolution and Re-Classification
  32. GRB 080121: Nearby SDSS galaxies
  33. GRB 080123: Swift-XRT refined analysis
  34. GRB 080123: Swift/UVOT refined analysis
  35. X-ray transient in NGC 2770: RTT150 optical observations
  36. GRB 080123, Swift-BAT refined analysis
  37. GRB 080120: GROND confirmation of the optical afterglow
  38. XRF 080109 / SN 2008D: GMRT radio observation at 1280 MHz
  39. VLA radio upper limit on GRB 080120
  40. GRB 080120: Swift-XRT refined analysis
  41. UVOT detection of GRB080120
  42. GRB 080120: GROND detection
  43. GRB080120: Swift XRT position
  44. XRF 080109 / SN 2008D: 1.4 GHz WSRT Radio Observations
  45. Transient in NGC2770 / SN2008D: Metallicity of nearby HII regions
  46. Transient XRF 080109 / SN 2008D: Mount Abu NIR observations
  47. XRF 080109 / SN 2008D: WSRT Radio Detection
  48. Transient 080109/ SN 2008D, metallicity of the host galaxy
  49. Transient 080109/ SN 2008D, IR Spectrum
  50. XRF 080109 / SN 2008D: optical observations
  51. NGC 2770B has the same redshift as NGC 2770
  52. Swift UVOT Monitoring of the SN 2008D Brightening (Transient in NGC 2770)
  53. XRF 080109 / SN 2008D: spectroscopic evolution
  54. optical observations, XRT in NGC 2770
  55. XRF 080109/SN 2008D: PROMPT Optical Imaging
  56. Gemini-South observations of XRF 080109 / SN 2008D
  57. Swift observations of the X-ray transient in NGC 2770 (aka SN2008D)
  58. Discovery of Radio Emission from Transient in NGC 2770
  59. XRF 080109 in NGC2770: NIR observations at TNG
  60. XRB 080109/SN 2008D: Early decline in brightness and change in colors
  61. XRB 080109/SN 2008D:PAIRITEL NIR observations and t_0 from Swift
  62. XRF 080109 in NGC2770: Detectable Superluminal Motion
  63. Detailed Spectroscopic ID of SN 2008D (Transient in NGC 2770)
  64. XRF in NGC 2770: Search for X-ray periodicity
  65. Refined Swift-XRT analysis of the transient in NGC 2770
  66. Transient in NGC 2770: spectroscopic evidence for a SN
  67. Refined Swift UVOT Analysis of SN 2008D (Transient in NGC 2770)
  68. Opticall follow-ups for the X-ray transient in NGC 2770
  69. X-ray transient in NGC 2770: Optical observations with Astrotel-Caucasus
  70. Early OT detection of XRF in NGC 2770 in Asiago frames
  71. Bright X-ray transient / possible XRF in NGC 2770: TNG R imaging
  72. Possible XRF in NGC 2770 - NOT observations of the optical counterpart
  73. Bright X-ray Transient (a XRF? ) in NGC 2770 - A SN optical counterpart?
  74. GRB 071227: Suzaku WAM observation of the prompt emission
  75. GRB 071227: optical afterglow
  76. Further Swift-BAT analysis of GRB 071227
  77. Konus-Wind observation of GRB 071227
  78. GRB 071227: Magellan redshift confirmation
  79. GRB 071227: Swift-XRT refined analysis
  80. GRB 071227: VLT probable redshift of the candidate host galaxy
  81. GRB 071227: Magellan observations
  82. GRB071227: Swift/UVOT refined analysis
  83. GRB 071227: REM NIR and Optical observations
  84. Swift-BAT refined analysis of short GRB 071227
  85. GRB071020: optical observations
  86. GRB 070429B: Possible UVOT Detection of an Optical Afterglow
  87. Swift-BAT trigger 298308 is not a GRB
  88. GRB 071125: Suzaku WAM observation of the prompt emission
  89. GRB 070429B: Probable host galaxy and redshift
  90. GRB 071129, Swift-BAT refined analysis
  91. Konus-Wind and Konus-A observations of GRB 071125
  92. GRB 071112C: Optical/NIR observations
  93. Disregard the "GRB 071126" position
  94. VLA radio detection of GRB 071122
  95. GRB071122: Swift/UVOT Observations
  96. GRB071104: NIR Afterglow Candidate at TNG
  97. GRB 071122: MASTER optical observation
  98. GRB 071122, Swift-BAT refined analysis
  99. GRB 071122 Swift XRT position update sent in error.
  100. GRB 071122 Swift-XRT refined analysis

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