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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"

27561 results found.

  1. GRB041006: Fading X-ray Afterglow Observed with Chandra
  2. GRB041006: VLT observations of the afterglow and host galaxy
  3. GRB041006: Optical observations and Potential host galaxy
  4. GRB041006, BVRcIc field calibration
  5. GRB 041006: SARA afterglow observations
  6. Search for SN light in XRF 040912 with MEGACAM
  7. GRB 040916: Afterglow Color at Early Times
  8. GRB 041006 Optical afterglow observations
  9. GRB 041006: BR observations with VATT
  10. GRB 041006: Redshift confirmed
  11. GRB041006: Liverpool Telescope optical observations
  12. GRB 041006: Colour measurement
  13. GRB041006: break in the light curve
  14. GRB 041006: Radio Observations
  15. GRB041006, further submilllimetre observations
  16. GRB 041006 : optical follow-up observation at Lulin Observatory
  17. GRB 041006 : Optical follow-up observation at TAROT
  18. GRB041006: Optical photometry and spectroscopy at TNG
  19. GRB041006 (= H3570): Chandra Observations In Progress
  20. GRB 041006 : optical observation at Bisei
  21. GRB041006, optical I observation
  22. GRB041006, submillimetre observations
  23. GRB 041006: Optical decay
  24. GRB041006: Fading of optical afterglow candidate
  25. GRB 041006: Finding chart
  26. GRB 041006: Optical afterglow candidate
  27. GRB 040924: Second Epoch WSRT Radio Observations
  28. radio observations, GRB 040924
  29. GRB040924,optical observation
  30. GRB040924, RTT150 optical observation
  31. GRB 040924: detection of possible host galaxy by Subaru
  32. GRB040924, RTT150 optical observation
  33. GRB040924: Afterglow magnitude at t=17.5hr
  34. GRB 040924: WSRT Radio Observations
  35. GRB 040924: Subaru NIR observation
  36. GRB040924: Optical afterglow properties
  37. GRB 040924, optical follow-up
  38. GRB040924 (H3564): Optical afterglow candidate
  39. XRF 040912: Radio Observations
  40. XRF 040916: Radio Observations
  41. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  42. TAROT Observations of GRB 040916 (HETE #3558)
  43. GRB040912(=H3557): Candidate Optical Afterglow
  44. XRF040912, BVRcIc field calibration
  45. XRF040916, BVRcIc field calibration
  46. GRB040916: Archival optical observations
  47. GRB 040912: Optical Observations
  48. GRB 040912, BVRI observations
  49. HETE 3557: Optical observations
  50. GRB040827: analysis of the XMM-Newton observation
  51. GRB040903, REM near-IR observation
  52. GRB 040827 - Radio Observations
  53. XMM-Newton Images of GRB 040827
  54. GRB040825A: Optical observations
  55. GRB040825A: Optical observations
  56. GRB 040827: optical and NIR observations at the VLT
  57. GRB 040827: UKIRT - 2nd epoch K-band imaging
  58. GRB 040827: 2nd epoch of Magellan K-band imaging
  59. GRB 040827: Detection of NIR afterglow
  60. GRB 040827: Possible detection of optical afterglow
  61. GRB040825B, BVRcIc field photometry
  62. GRB040825A, BVRcIc field photometry
  63. GRB 040825: Optical observations
  64. XRF040812: possible afterglow second Chandra observation
  65. GRB 040812: Second epoch CXO Observations
  66. XRF040812: possible afterglow
  67. CXO observation of GRB 040812
  68. GRB 040812: radio observations
  69. GRB 040810: Optical observations of a limited region
  70. GRB040624: optical monitoring at TNG
  71. XRF040701: Second-Epoch Chandra Observations
  72. XRF040701: VLA Observations
  73. XRF040701: First-Epoch Chandra Observations
  74. GRB 030329: Rebrightening of hyperluminal ejecta.
  75. GRB040511: Retraction of redshift identification
  76. GRB 040511, very fast decay?
  77. GRB 030324: Detection and Color of Host Galaxy
  78. GRB040511: Redshift identifcation
  79. GRB 040511: Optical limit
  80. GRB040511: Candidate optical/NIR afterglow
  81. GRB and XRF on April 27, 2004. Detection by Konus-Wind and Helicon (Coronas-F)
  82. GRB040422, BVRcIc field calibration
  83. HETE/IPN localization of GRB040403A (=H3143, a long burst) and GRB040403B(=H3144, a short/hard burst)
  84. GRB 040403: Optical Observations
  85. GRB 040323, a dark GRB ?
  86. GRB040223: Deep NIR NTT data re-analysis
  87. GRB 040223: XMM-Newton results
  88. GRB040223, improved XMM position
  89. GRB 031203, possible supernova
  90. MASTER: RXTE GRB040308 optical observation
  91. INTEGRAL detection of activity from SGR1806-20
  92. RXTE GRB040229 optical observation: no candidate
  93. GRB 040228 Optical observations
  94. GRB 040223 : Optical observation (non-detection)
  95. GRB031220: 2nd Chandra observation and X-ray afterglow candidate
  96. GRB031203: Chandra Observations
  97. GRB040106: refined X-ray transient position
  98. GRB040106, likely optical afterglow
  99. GRB040106: Second Epoch Optical Observations
  100. GRB 031220: Optical observations of Chandra X-ray sources

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