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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"

18330 results found.

  1. GRB 080130: further Swift XRT observations confirm fading source
  2. GRB 080129: Swift/UVOT Refined Upper Limits
  3. Swift/UVOT observations of GRB080130
  4. GRB 080130: REM NIR observations
  5. GRB 080130(?): Swift XRT observation
  6. GRB 080129: Swift-XRT refined analysis
  7. GRB 080129: KAIT optical limits
  8. GRB 080129: TAROT La Silla observatory optical observations
  9. GRB 080129: GROND detection in all bands, and fading
  10. GRB 080129: GROND detection of the optical/NIR afterglow, and fading
  11. GRB 080129: Enhanced Swift-XRT position
  12. GRB 080129: Gemini-South Imaging Observations
  13. GRB 080129 (?): UVOT Upper Limits
  14. GRB 080121: Swift/UVOT upper limits
  15. SNe 2008D and 2007uy: Chandra Detections
  16. GRB 080121: Enhanced Swift-XRT position
  17. IPN triangulation of GRB080122
  18. GRB 080121: Nearby SDSS galaxies
  19. GRB 080123: Swift/UVOT refined analysis
  20. GRB 080123: Enhanced Swift-XRT position
  21. GRB 080123: Swift detection of a short burst
  22. GRB 080120: GROND confirmation of the optical afterglow
  23. VLA radio upper limit on GRB 080120
  24. GRB 080120: Swift-XRT refined analysis
  25. GRB080120: Swift XRT position
  26. Transient XRF 080109 / SN 2008D: Mount Abu NIR observations
  27. XRF 080109 / SN 2008D: UKIRT JHK imaging
  28. optical observations, XRT in NGC 2770
  29. Gemini-South observations of XRF 080109 / SN 2008D
  30. Swift observations of the X-ray transient in NGC 2770 (aka SN2008D)
  31. Discovery of Radio Emission from Transient in NGC 2770
  32. XRF 080109 in NGC2770: NIR observations at TNG
  33. XRB 080109/SN 2008D: Early decline in brightness and change in colors
  34. XRB 080109/SN 2008D:PAIRITEL NIR observations and t_0 from Swift
  35. Refined Swift-XRT analysis of the transient in NGC 2770
  36. Swift UVOT Observations of the X-ray transient in NGC 2770
  37. GRB 071227: optical afterglow
  38. Further Swift-BAT analysis of GRB 071227
  39. GRB 071227: Swift-XRT refined analysis
  40. GRB 071227: VLT probable redshift of the candidate host galaxy
  41. GRB071227: Swift/UVOT refined analysis
  42. GRB 071227: REM NIR and Optical observations
  43. GRB 071227: Swift detection of a burst
  44. GRB 070429B: Possible UVOT Detection of an Optical Afterglow
  45. GRB 070429B: Probable host galaxy and redshift
  46. GRB 071126: Enhanced Swift-XRT position
  47. GRB071122: Swift/UVOT Observations
  48. GRB071104: NIR Afterglow Candidate at TNG
  49. GRB 071122 Swift-XRT refined analysis
  50. GRB 071122: P60 Optical Afterglow Candidate
  51. GRB 071122: Swift detection of a burst
  52. GRB 071118: P60 Observations
  53. GRB071118 MITSuME OAO optical observation
  54. GRB 071118: Observations from OSN
  55. GRB 071117: VLT observations and probable redshift
  56. Swift/UVOT observations of GRB071118
  57. Swift XRT follow-up observations of GRB071008
  58. Swift/UVOT upper limits for GRB 071117
  59. GRB071118: Swift XRT refined analysis
  60. GRB 071117: Gemini Optical Afterglow Discovery
  61. GRB 071117: TAROT La Silla observatory optical observations
  62. GRB 071118: Swift detection of a burst
  63. GRB 071117: Gemini Observations
  64. Swift detection of MXB 0656-072
  65. GRB 071112C: Optical and NIR data observed with KANATA
  66. GRB 071112C MITSuME Akeno early optical observation
  67. GRB 071112C: SARA upper limit
  68. GRB 071112C : Second Epoch Lulin R-band observations
  69. GRB071112C MITSuME Okayama Optical Observation
  70. GRB 071112C: Swift-BAT refined analysis
  71. GRB 071112C: Swift XRT refined analysis
  72. Swift UVOT upper limits of GRB071112B
  73. GRB 071112B: Gemini Optical Imaging
  74. GRB 071112B: Swift-XRT preliminary analysis
  75. GRB 071112C : Lulin R-band observation
  76. GRB 071112C: TAROT Calern observatory optical observations
  77. Swift XRT follow-up observations of GRB071028B
  78. GRB071112C Xinglong_TNT_and_EST_afterglow observations
  79. GRB 071112C: Optical and NIR afterglows observed with KANATA
  80. GRB 071112C: Swift detection of a burst with an optical counterpart
  81. GRB 071112: Swift detection of a possible burst
  82. Swift/UVOT initial analysis of GRB071109
  83. GRB 071109: further Swift-XRT analysis
  84. GRB 071109: TAROT Calern observatory optical observations
  85. GRB 071109: Swift-XRT possible X-ray counterpart
  86. GRB 071109: A long GRB detected by INTEGRAL
  87. GRB 071104: Possible Swift UVOT Afterglow Candidate
  88. GRB 071104: Swift-XRT position
  89. Swift XRT and UVOT observations of GRB071028B
  90. GRB071101: Optical and NIR upper limits by KANATA
  91. GRB0711101: Two new source from Xinglong TNT observation
  92. GRB 071101: TAROT Calern observatory optical observations
  93. GRB071101 LOAO B,V,R,I observation
  94. GRB 071031: Swift-XRT Team refined analysis
  95. GRB 071020: MITSuME Akeno optical observations
  96. GRB 071031: REM NIR and Optical observation
  97. GRB 071031: Swift detection of a burst with an optical counterpart
  98. GRB 071028B Swift-BAT detection of a burst
  99. GRB071025: Optical+NIR observations
  100. GRB 071028: SARA observations of variable source

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