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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"

41192 results found.

  1. Two non-burst Swift SubThreshold triggers
  2. Transient 080109/SN 2008D: Spectroscopic Evolution and Re-Classification
  3. IPN triangulation of GRB080122
  4. GRB 080121: Nearby SDSS galaxies
  5. GRB 080121: Swift-BAT detection of a very weak, short burst
  6. GRB 080123: Swift-XRT refined analysis
  7. X-ray transient in NGC 2770: RTT150 optical observations
  8. GRB 080123, Swift-BAT refined analysis
  9. GRB 080123: Enhanced Swift-XRT position
  10. GRB 080123: Swift detection of a short burst
  11. GRB 080120: GROND confirmation of the optical afterglow
  12. XRF 080109 / SN 2008D: GMRT radio observation at 1280 MHz
  13. GRB 080120: Swift-XRT refined analysis
  14. UVOT detection of GRB080120
  15. GRB 080120: GROND detection
  16. GRB 080120 : Planned XMM-Newton observation
  17. GRB080120: Swift XRT position
  18. GRB 080120: a long GRB detected by INTEGRAL
  19. XRF 080109 / SN 2008D: 1.4 GHz WSRT Radio Observations
  20. Transient in NGC2770 / SN2008D: Metallicity of nearby HII regions
  21. Transient XRF 080109 / SN 2008D: Mount Abu NIR observations
  22. XRF 080109 / SN 2008D: WSRT Radio Detection
  23. Transient 080109/ SN 2008D, metallicity of the host galaxy
  24. Transient 080109/ SN 2008D, IR Spectrum
  25. XRF 080109 / SN 2008D: optical observations
  26. NGC 2770B has the same redshift as NGC 2770
  27. Swift UVOT Monitoring of the SN 2008D Brightening (Transient in NGC 2770)
  28. XRF 080109 / SN 2008D: spectroscopic evolution
  29. XRF 080109 / SN 2008D: UKIRT JHK imaging
  30. optical observations, XRT in NGC 2770
  31. XRF 080109/SN 2008D: PROMPT Optical Imaging
  32. Gemini-South observations of XRF 080109 / SN 2008D
  33. Swift observations of the X-ray transient in NGC 2770 (aka SN2008D)
  34. Discovery of Radio Emission from Transient in NGC 2770
  35. XRF 080109 in NGC2770: NIR observations at TNG
  36. XRB 080109/SN 2008D: Early decline in brightness and change in colors
  37. XRB 080109/SN 2008D:PAIRITEL NIR observations and t_0 from Swift
  38. XRF 080109 in NGC2770: Detectable Superluminal Motion
  39. Detailed Spectroscopic ID of SN 2008D (Transient in NGC 2770)
  40. XRF in NGC 2770: Search for X-ray periodicity
  41. Spectroscopic classification of SN 2008D (Transient in NGC 2770)
  42. Refined Swift-XRT analysis of the transient in NGC 2770
  43. Transient in NGC 2770: spectroscopic evidence for a SN
  44. Refined Swift UVOT Analysis of SN 2008D (Transient in NGC 2770)
  45. Opticall follow-ups for the X-ray transient in NGC 2770
  46. X-ray transient in NGC 2770: Optical observations with Astrotel-Caucasus
  47. Optical Spectroscopy of the Transient in NGC 2770
  48. Swift UVOT Observations of the X-ray transient in NGC 2770
  49. Early OT detection of XRF in NGC 2770 in Asiago frames
  50. Bright X-ray transient / possible XRF in NGC 2770: TNG R imaging
  51. Possible XRF in NGC 2770 - NOT observations of the optical counterpart
  52. Bright X-ray Transient (a XRF? ) in NGC 2770 - A SN optical counterpart?
  53. Bright X-ray Transient in NGC 2770 - A low-luminosity XRF?
  54. GRB 071227: Suzaku WAM observation of the prompt emission
  55. GRB 071227: optical afterglow
  56. Further Swift-BAT analysis of GRB 071227
  57. Konus-Wind observation of GRB 071227
  58. GRB 071227: Magellan redshift confirmation
  59. GRB 071227: Swift-XRT refined analysis
  60. GRB 071227: VLT probable redshift of the candidate host galaxy
  61. GRB 071227: Magellan observations
  62. GRB071227: Swift/UVOT refined analysis
  63. GRB 071227: REM NIR and Optical observations
  64. Swift-BAT refined analysis of short GRB 071227
  65. GRB 071227: Swift detection of a burst
  66. GRB071020: optical observations
  67. GRB 070429B: Possible UVOT Detection of an Optical Afterglow
  68. Swift-BAT trigger 298308 is not a GRB
  69. GRB 071208?: Swift detection of a possible burst
  70. GRB 071125: Suzaku WAM observation of the prompt emission
  71. GRB 070429B: Probable host galaxy and redshift
  72. GRB 071129, Swift-BAT refined analysis
  73. GRB 071129: Swift detection of a burst
  74. IPN triangulation of very bright GRB 071125
  75. GRB 071112C: Optical/NIR observations
  76. GRB 071126: Enhanced Swift-XRT position
  77. GRB071122: Swift/UVOT Observations
  78. GRB071104: NIR Afterglow Candidate at TNG
  79. GRB 071122: MASTER optical observation
  80. GRB 071122, Swift-BAT refined analysis
  81. GRB 071122 Swift-XRT refined analysis
  82. GRB071122: Gemini Absorption redshift
  83. GRB 071122: P60 Optical Afterglow Candidate
  84. GRB 071122: ROTSE-III Optical Limits
  85. GRB 071122: Swift detection of a burst
  86. GRB 071118: P60 Observations
  87. GRB071118 MITSuME OAO optical observation
  88. GRB 071118: Observations from OSN
  89. GRB 071117: VLT observations and probable redshift
  90. Swift/UVOT observations of GRB071118
  91. GRB 071117: Swift-XRT revised position
  92. Konus-Wind and Konus-A observations of GRB 071117
  93. Swift XRT follow-up observations of GRB071008
  94. GRB071118: Swift XRT refined analysis
  95. GRB 071117: Gemini Optical Afterglow Discovery
  96. GRB 071118, Swift-BAT refined analysis
  97. GRB 071117: TAROT La Silla observatory optical observations
  98. GRB 071112B: Gemini Image Differencing
  99. GRB 071118: Swift detection of a burst
  100. GRB 071117: Gemini Observations

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