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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"
  1. GRB 080207: TAROT Calern observatory optical observations
  2. GRB 080207: Swift-XRT Refined Analysis
  3. GRB 080207: Enhanced Swift-XRT position
  4. GRB 080207: Swift detection of a burst
  5. Konus-Wind observation of GRB 080204
  6. GRB 080205 optical upper limit
  7. GRB 080205: MASTER optical observation
  8. GRB 080205: optical observation
  9. VLA radio upper limit on GRB 080205
  10. INT+WFC R-band observations of GRB 080205
  11. GRB 080205, Swift-BAT refined analysis
  12. IPN localization of very hard GRB 080204
  13. GRB 080205: Swift XRT refined analysis
  14. GRB 080205: OA evolution from KAIT observations
  15. GRB 080205: Swift/UVOT observations
  16. GRB 080205: Enhanced Swift-XRT position
  17. GRB 080205: KAIT OA detection
  18. GRB 080205: Swift detection of a burst
  19. Swift-BAT Trigger #302454, correction of GCN notice, update on AX J1749.1-2639
  20. GRB 080130: Swift-BAT refined analysis
  21. GRB 080130: further Swift XRT observations confirm fading source
  22. GRB 080129: Swift/UVOT Refined Upper Limits
  23. Swift/UVOT observations of GRB080130
  24. GRB 080130: REM NIR observations
  25. GRB 080130(?): Swift XRT observation
  26. GRB 080130?: Detection of a possible burst by BATSS
  27. GRB 080129: Optical observations from OSN
  28. GRB 080129: Swift-XRT refined analysis
  29. X-ray transient in NGC 2770: RTT150 optical observations
  30. GRB 080129: KAIT optical limits
  31. GRB 080123: Early afterglow detection with BATSS (BAT Slew Survey)
  32. GRB 080129: optical limit by Pi of the Sky
  33. GRB 080129, Swift-BAT refined analysis
  34. GRB 080129: TAROT La Silla observatory optical observations
  35. GRB 080129: Gemini-South photometry
  36. GRB 080129: GROND detection in all bands, and fading
  37. GRB 080129: GROND detection of the optical/NIR afterglow, and fading
  38. GRB 080129: Enhanced Swift-XRT position
  39. GRB 080129: Gemini-South Imaging Observations
  40. GRB 080129: Swift XRT position
  41. GRB 080129 (?): UVOT Upper Limits
  42. GRB 080129 (?): Swift detection of a possible burst
  43. A new website of high-level data products for Swift GRBs
  44. GRB 080121: Upper limit on X-ray afterglow
  45. GRB 080123 : Suzaku WAM observation of the prompt emission
  46. Swift trigger(=301779) is not a GRB
  47. Transient 080109/SN 2008D: Spectroscopic Evolution
  48. GRB 080122: pseudo-z= 1.93 from prompt emission spectrum
  49. Konus-Wind observation of GRB 080122
  50. GRB 080122 : Suzaku WAM observation of the prompt emission
  51. GRB 080121: Swift/UVOT upper limits
  52. SNe 2008D and 2007uy: Chandra Detections
  53. GRB 080121 position was incorrect
  54. GRB 080121: Enhanced Swift-XRT position
  55. Two non-burst Swift SubThreshold triggers
  56. Transient 080109/SN 2008D: Spectroscopic Evolution and Re-Classification
  57. IPN triangulation of GRB080122
  58. GRB 080121: Nearby SDSS galaxies
  59. GRB 080121: Swift-BAT detection of a very weak, short burst
  60. GRB 080123: Swift-XRT refined analysis
  61. GRB 080123: Swift/UVOT refined analysis
  62. X-ray transient in NGC 2770: RTT150 optical observations
  63. GRB 080123, Swift-BAT refined analysis
  64. GRB 080123: Enhanced Swift-XRT position
  65. GRB 080123: Swift detection of a short burst
  66. GRB 080120: GROND confirmation of the optical afterglow
  67. XRF 080109 / SN 2008D: GMRT radio observation at 1280 MHz
  68. VLA radio upper limit on GRB 080120
  69. GRB 080120: Swift-XRT refined analysis
  70. UVOT detection of GRB080120
  71. GRB 080120: GROND detection
  72. GRB 080120 : Planned XMM-Newton observation
  73. GRB080120: Swift XRT position
  74. GRB 080120: a long GRB detected by INTEGRAL
  75. XRF 080109 / SN 2008D: 1.4 GHz WSRT Radio Observations
  76. Transient in NGC2770 / SN2008D: Metallicity of nearby HII regions
  77. Transient XRF 080109 / SN 2008D: Mount Abu NIR observations
  78. XRF 080109 / SN 2008D: WSRT Radio Detection
  79. Transient 080109/ SN 2008D, metallicity of the host galaxy
  80. Transient 080109/ SN 2008D, IR Spectrum
  81. XRF 080109 / SN 2008D: optical observations
  82. NGC 2770B has the same redshift as NGC 2770
  83. Swift UVOT Monitoring of the SN 2008D Brightening (Transient in NGC 2770)
  84. XRF 080109 / SN 2008D: spectroscopic evolution
  85. XRF 080109 / SN 2008D: UKIRT JHK imaging
  86. optical observations, XRT in NGC 2770
  87. XRF 080109/SN 2008D: PROMPT Optical Imaging
  88. Gemini-South observations of XRF 080109 / SN 2008D
  89. Swift observations of the X-ray transient in NGC 2770 (aka SN2008D)
  90. Discovery of Radio Emission from Transient in NGC 2770
  91. XRF 080109 in NGC2770: NIR observations at TNG
  92. XRB 080109/SN 2008D: Early decline in brightness and change in colors
  93. XRB 080109/SN 2008D:PAIRITEL NIR observations and t_0 from Swift
  94. XRF 080109 in NGC2770: Detectable Superluminal Motion
  95. Detailed Spectroscopic ID of SN 2008D (Transient in NGC 2770)
  96. XRF in NGC 2770: Search for X-ray periodicity
  97. Spectroscopic classification of SN 2008D (Transient in NGC 2770)
  98. Refined Swift-XRT analysis of the transient in NGC 2770
  99. Transient in NGC 2770: spectroscopic evidence for a SN
  100. Refined Swift UVOT Analysis of SN 2008D (Transient in NGC 2770)

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