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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"

26037 results found.

  1. GRB041006, BVRcIc field calibration
  2. GRB 041006: SARA afterglow observations
  3. Search for SN light in XRF 040912 with MEGACAM
  4. GRB 040916: Afterglow Color at Early Times
  5. GRB 041006 Optical afterglow observations
  6. GRB 041006: BR observations with VATT
  7. GRB 041006: Redshift confirmed
  8. GRB041006: Liverpool Telescope optical observations
  9. GRB 041006: Colour measurement
  10. GRB041006: break in the light curve
  11. GRB 041006: Radio Observations
  12. GRB041006, further submilllimetre observations
  13. GRB 041006 : optical follow-up observation at Lulin Observatory
  14. GRB 041006 : Optical follow-up observation at TAROT
  15. GRB041006: Optical photometry and spectroscopy at TNG
  16. GRB041006 (= H3570): Chandra Observations In Progress
  17. GRB 041006 : optical observation at Bisei
  18. GRB041006, optical I observation
  19. GRB041006, submillimetre observations
  20. GRB 041006: Optical decay
  21. GRB041006: Fading of optical afterglow candidate
  22. GRB 041006: Finding chart
  23. GRB 041006: Optical afterglow candidate
  24. GRB 040924: Second Epoch WSRT Radio Observations
  25. radio observations, GRB 040924
  26. GRB040924,optical observation
  27. GRB040924, RTT150 optical observation
  28. GRB 040924: detection of possible host galaxy by Subaru
  29. GRB040924, RTT150 optical observation
  30. GRB040924: Afterglow magnitude at t=17.5hr
  31. GRB 040924: WSRT Radio Observations
  32. GRB 040924: Subaru NIR observation
  33. GRB040924: Optical afterglow properties
  34. GRB040924 (H3564): Optical afterglow candidate
  35. XRF 040912: Radio Observations
  36. XRF 040916: Radio Observations
  37. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  38. TAROT Observations of GRB 040916 (HETE #3558)
  39. GRB040912(=H3557): Candidate Optical Afterglow
  40. XRF040912, BVRcIc field calibration
  41. XRF040916, BVRcIc field calibration
  42. GRB040916: Archival optical observations
  43. GRB040916: Optical observations
  44. GRB 040912: Optical Observations
  45. GRB 040912, BVRI observations
  46. HETE 3557: Optical observations
  47. GRB040827: analysis of the XMM-Newton observation
  48. GRB 040827 - Radio Observations
  49. GRB040825A: Optical observations
  50. GRB040825A: Optical observations
  51. GRB 040827: optical and NIR observations at the VLT
  52. GRB 040827: UKIRT - 2nd epoch K-band imaging
  53. GRB 040827: 2nd epoch of Magellan K-band imaging
  54. GRB 040827: Detection of NIR afterglow
  55. GRB 040827: Possible detection of optical afterglow
  56. GRB040825B, BVRcIc field photometry
  57. GRB040825A, BVRcIc field photometry
  58. GRB 040825: Optical observations
  59. XRF040812: possible afterglow second Chandra observation
  60. GRB 040812: Second epoch CXO Observations
  61. XRF040812: possible afterglow
  62. GRB 040810: Optical observations of a limited region
  63. XRF040701: Second-Epoch Chandra Observations
  64. XRF040701: First-Epoch Chandra Observations
  65. GRB 030329: Rebrightening of hyperluminal ejecta.
  66. GRB040511: Retraction of redshift identification
  67. GRB 040511, very fast decay?
  68. GRB 030324: Detection and Color of Host Galaxy
  69. GRB040511: Redshift identifcation
  70. GRB 040511: Optical limit
  71. GRB040511: Candidate optical/NIR afterglow
  72. GRB040422, BVRcIc field calibration
  73. GRB040422: optical and NIR observations at the VLT
  74. GRB 040403: Optical Observations
  75. GRB 040323, a dark GRB ?
  76. GRB040223: Deep NIR NTT data re-analysis
  77. GRB 040223: XMM-Newton results
  78. GRB040223, improved XMM position
  79. GRB 031203, possible supernova
  80. MASTER: RXTE GRB040308 optical observation
  81. RXTE GRB040229 optical observation: no candidate
  82. GRB 040228 Optical observations
  83. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  84. GRB031203: Chandra Observations
  85. GRB040106: refined X-ray transient position
  86. GRB040106, likely optical afterglow
  87. GRB040106: Second Epoch Optical Observations
  88. GRB 031220: Optical observations of Chandra X-ray sources
  89. GRB031220: Palomar Observations
  90. GRB031203, improved XMM position
  91. GRB 031203: Discovery of a dust echo
  92. GRB 021203: A Normal GRB viewed far off axis?
  93. GRB 031203: Variable Radio Source
  94. GRB 031203: Optical/IR Astrometry
  95. GRB 031203: Radio detection
  96. GRB 031203: z ~ 10 or Fragmented Dust in the Circumburst Environment?
  97. GRB 031111: Optical observations
  98. SN 2003jd (SN/GRB?) - possible association with GRB 030929
  99. GRB 031026 (=H2882): Evidence for High Redshift from Prompt
  100. GRB030329: radio observations at RT-22 (CrAO)

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