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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"

23410 results found.

  1. GRB 080129: Gemini-South Imaging Observations
  2. GRB 080129 (?): UVOT Upper Limits
  3. GRB 080129 (?): Swift detection of a possible burst
  4. GRB 080121: Upper limit on X-ray afterglow
  5. GRB 080121: Swift/UVOT upper limits
  6. SNe 2008D and 2007uy: Chandra Detections
  7. GRB 080121: Enhanced Swift-XRT position
  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/UVOT refined analysis
  12. GRB 080123: Enhanced Swift-XRT position
  13. GRB 080123: Swift detection of a short burst
  14. GRB 080120: GROND confirmation of the optical afterglow
  15. VLA radio upper limit on GRB 080120
  16. UVOT detection of GRB080120
  17. GRB080120: Swift XRT position
  18. GRB 080120: a long GRB detected by INTEGRAL
  19. Transient XRF 080109 / SN 2008D: Mount Abu NIR observations
  20. NGC 2770B has the same redshift as NGC 2770
  21. Swift UVOT Monitoring of the SN 2008D Brightening (Transient in NGC 2770)
  22. XRF 080109 / SN 2008D: UKIRT JHK imaging
  23. optical observations, XRT in NGC 2770
  24. XRF 080109/SN 2008D: PROMPT Optical Imaging
  25. Gemini-South observations of XRF 080109 / SN 2008D
  26. Swift observations of the X-ray transient in NGC 2770 (aka SN2008D)
  27. Discovery of Radio Emission from Transient in NGC 2770
  28. XRF 080109 in NGC2770: NIR observations at TNG
  29. XRB 080109/SN 2008D: Early decline in brightness and change in colors
  30. XRB 080109/SN 2008D:PAIRITEL NIR observations and t_0 from Swift
  31. XRF 080109 in NGC2770: Detectable Superluminal Motion
  32. Spectroscopic classification of SN 2008D (Transient in NGC 2770)
  33. Refined Swift-XRT analysis of the transient in NGC 2770
  34. Refined Swift UVOT Analysis of SN 2008D (Transient in NGC 2770)
  35. Early OT detection of XRF in NGC 2770 in Asiago frames
  36. Possible XRF in NGC 2770 - NOT observations of the optical counterpart
  37. Bright X-ray Transient in NGC 2770 - A low-luminosity XRF?
  38. GRB 071227: optical afterglow
  39. Further Swift-BAT analysis of GRB 071227
  40. Konus-Wind observation of GRB 071227
  41. GRB 071227: Swift-XRT refined analysis
  42. GRB 071227: VLT probable redshift of the candidate host galaxy
  43. GRB 071227: Magellan observations
  44. GRB071227: Swift/UVOT refined analysis
  45. GRB 071227: REM NIR and Optical observations
  46. GRB 071227: Swift detection of a burst
  47. GRB 070429B: Possible UVOT Detection of an Optical Afterglow
  48. GRB 071208?: Swift detection of a possible burst
  49. GRB 071125: Suzaku WAM observation of the prompt emission
  50. GRB 070429B: Probable host galaxy and redshift
  51. GRB 071129, Swift-BAT refined analysis
  52. GRB 071129: Swift detection of a burst
  53. Konus-Wind and Konus-A observations of GRB 071125
  54. IPN triangulation of very bright GRB 071125
  55. GRB 071126: Enhanced Swift-XRT position
  56. GRB071122: Swift/UVOT Observations
  57. GRB071104: NIR Afterglow Candidate at TNG
  58. GRB 071122 Swift-XRT refined analysis
  59. GRB 071122: P60 Optical Afterglow Candidate
  60. GRB 071122: ROTSE-III Optical Limits
  61. GRB 071122: Swift detection of a burst
  62. GRB 071118: P60 Observations
  63. GRB071118 MITSuME OAO optical observation
  64. GRB 071118: Observations from OSN
  65. GRB 071117: VLT observations and probable redshift
  66. Swift/UVOT observations of GRB071118
  67. Swift XRT follow-up observations of GRB071008
  68. Swift/UVOT upper limits for GRB 071117
  69. GRB071118: Swift XRT refined analysis
  70. GRB 071117: Gemini Optical Afterglow Discovery
  71. GRB 071118, Swift-BAT refined analysis
  72. GRB 071117: TAROT La Silla observatory optical observations
  73. GRB 071112B: Gemini Image Differencing
  74. GRB 071118: Swift detection of a burst
  75. GRB 071117: Gemini Observations
  76. VLT FORS2 observations of short hard GRB071112B
  77. GRB 071117: Initial Swift/UVOT observations
  78. GRB 071117: Swift detection of a bright burst
  79. Swift detection of MXB 0656-072
  80. GRB 071112C: Optical and NIR data observed with KANATA
  81. GRB 071112C MITSuME Akeno early optical observation
  82. GRB 071112C: SARA upper limit
  83. GRB 071112C : Second Epoch Lulin R-band observations
  84. GRB071112C MITSuME Okayama Optical Observation
  85. GRB 071112C: Swift-BAT refined analysis
  86. GRB 071112C: Swift XRT refined analysis
  87. GRB 071112C: Optical observations at Crni Vrh
  88. Swift UVOT upper limits of GRB071112B
  89. GRB 071112B: Gemini Optical Imaging
  90. GRB 071112B: Swift-XRT preliminary analysis
  91. GRB 071112C: Palomar Pre-Imaging
  92. GRB 071112C : Lulin R-band observation
  93. GRB 071112C: TAROT Calern observatory optical observations
  94. Swift XRT follow-up observations of GRB071028B
  95. GRB071112C Xinglong_TNT_and_EST_afterglow observations
  96. GRB 071112C: Optical and NIR afterglows observed with KANATA
  97. GRB 071112B: ROTSE-III Rapid Optical Limits
  98. GRB 071112C: Swift detection of a burst with an optical counterpart
  99. GRB 071112B: Swift detection of a short hard burst
  100. GRB 071112: Swift detection of a possible burst

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