Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

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"

21793 results found.

  1. GRB020127: Palomar and VLA Observations of Possible Counterparts
  2. GRB020127: Comparison of Chandra Epochs and Identification of Possible Counterparts
  3. SN2002ap (SN/GRB?) Echelle spectra
  4. SN2002ap (SN/GRB?) optical spectrographic observations
  5. GRB020127, WSRT radio observations
  6. GRB020127 Optical Observations
  7. SN 2002ap in M74
  8. SN2002ap (SN/GRB?) UBVRI Field Photometry
  9. GRB020127: Chandra Observations and Prospective Counterparts
  10. pre-SN2002ap (SN/GRB?) imaging of M74
  11. Type Ib/c SN2002ap (SN/GRB?)
  12. Type Ib/c SN2002ap (SN/GRB?) Radio Observations
  13. GRB020124, optical observations
  14. GRB020127: Optical observations
  15. GRB 020127, I-band observations starting 3.14-hr after the event
  16. GRB020127 Optical Observations -- Erratum to GCN 1230
  17. GRB010921 Optical Observations
  18. GRB020124: Optical observations
  19. VLT observations of GRB 020124: The fading optical/near-infrared afterglow
  20. GRB020124: Optical observations
  21. GRB 020124: Optical observations
  22. GRB 020124 Optical Observations
  23. IPN observations of SGR1806-20
  24. GRB 020124: Optical afterglow
  25. HETE 1896: Optical observations
  26. GRB optical counterpart candidate in GCN 1217 is M dwarf
  27. Possible optical counterpart to a GRB
  28. GRB011212, Optical Observations
  29. Optical polarization observations for GRB011211
  30. GRB 011211: Detection of the Probable Host Galaxy
  31. GRB 011130 and GRB 011212 - Milagro GeV/TeV Observations
  32. Color indices of the afterglow of GRB011211
  33. GRB011212: Optical observations at Gunma
  34. GRB 011130: Optical Observations of X-ray and Radio Sources
  35. GRB 011130, Radio/X-ray Comparison
  36. GRB011212: Optical observations
  37. GRB 011212: optical observation at Asiago
  38. GRB 011211: TNG Spectroscopic Observations
  39. GRB 011211, Optical Observations
  40. GRB011212: Optical observations
  41. GRB 011211 Optical Observations: Likely Afterglow
  42. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  43. GRB 011130: Optical Observations of Chandra Sources
  44. GRB 011130: Optical Observations of Chandra sources
  45. GRB011130 (XRF011130) Chandra Observations
  46. GRB 011130: Magellan spectroscopy
  47. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  48. GRB011130, optical observations
  49. GRB 011130, K band observations
  50. GRB011130, optical observations
  51. GRB011130 (XRF011130) optical observations
  52. GRB011130 (XRF011130) SDSS PT i-band observations
  53. XRF011130: Infrared Observations
  54. GRB011130, Radio Observations
  55. GRB011130 (=XRF011130), Optical Observations
  56. XRF011130: NEAT Optical Observations
  57. GRB001109, Radio Monitoring
  58. GRB 011121
  59. GRB 011121: J-band observations
  60. GRB 011121: NIR observations, host galaxy?
  61. GRB010921 - Milagro GeV/TeV Observations
  62. GRB 011121: HST Scheduled
  63. GRB011121: fainter still
  64. GRB011121: UBRI Observations
  65. GRB011121
  66. GRB 011121: Radio Observations
  67. GRB011121: continued decay
  68. GRB 011121: Detection of Bright IR Counterpart
  69. GRB011121: possible redshift, continued decay
  70. GRB011121: fading behavior
  71. GRB011121: possible optical counterpart
  72. XRF011030: J and K band observations
  73. XRF011030: Chandra Observations
  74. GRB 011030: K-band observations
  75. GRB011030: Z-band observations
  76. GRB 011030 R band observations
  77. The X-ray Flash 011030 ('GRB 011030')
  78. Non-triggered burst 011030 ("GRB 011030")
  79. The Radio Afterglow from the X-ray Rich GRB 011030
  80. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  81. GRB 970828: HST Observations of the Host Galaxy
  82. GRB 000131: HST Detection of the Host Galaxy
  83. GRB 970828: HST Observations of the Host Galaxy
  84. GRB010921, optical observation
  85. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  86. GRB011019: Subaru Optical Observations
  87. GRB 011030 I-band Observations
  88. GRB 011030 K-band Observations
  89. GRB010921, optical observations
  90. GRB 011030, WSRT radio observations
  91. GRB 011030, Radio observations
  92. GRB 011030, R-band observations
  93. GRB011019: NEAT Optical Observations
  94. GRB011019: ROTSE-III optical observations
  95. GRB 010921, I-band observations
  96. GRB011019: Optical observations
  97. GRB011019, optical observations -- correction
  98. GRB011019, optical observations
  99. GRB010921: Spectroscopy of the Host Galaxy
  100. GRB 010921: The afterglow of HETE #1761

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov