Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

44690 results found.

  1. XMM-Newton observation of GRB011211
  2. GRB 011211 Optical Observations: Likely Afterglow
  3. GRB011130 (=XRF011130): Further analysis of Chandra Target of
  4. GRB011211(=XRF011211): BeppoSAX refined positions
  5. BeppoSAX Alert: GRB011211(=XRF011211)
  6. GRB 011130: Optical Observations of Chandra Sources
  7. GRB 011130: Optical Observations of Chandra sources
  8. GRB011130 (XRF011130) Chandra Observations
  9. GRB011130 (=XRF011130): Scheduled Target of Opportunity
  10. GRB 011130: Magellan spectroscopy
  11. Sub-mm and Centimeter Detections of the Host Galaxy of GRB000418
  12. GRB011130, optical observations
  13. GRB 011130, K band observations
  14. GRB011130, optical observations
  15. GRB011130 (=XRF011130): Second Revised Localization by HETE
  16. GRB 011130 I-band Observation
  17. GRB011130 (XRF011130) optical observations
  18. GRB011130 (XRF011130) SDSS PT i-band observations
  19. XRF011130: Infrared Observations
  20. GRB011130, Radio Observations
  21. Detection of the X-ray afterglow of GRB011121 by BeppoSAX
  22. GRB011130 (=XRF011130), Optical Observations
  23. XRF011130: NEAT Optical Observations
  24. GRB011130 (=XRF011130): Revised Localization of an X-ray
  25. GRB001109, Radio Monitoring
  26. GRB 011121
  27. GRB011130 (=H1864): An X-Ray Rich GRB Detected by HETE
  28. GRB 011121: J-band observations
  29. GRB 011121: NIR observations, host galaxy?
  30. GRB010921 - Milagro GeV/TeV Observations
  31. GRB 011121: HST Scheduled
  32. GRB011121: fainter still
  33. Correction: GCN1157 (GRB 011121)
  34. GRB011121: UBRI Observations
  35. GRB011121
  36. GRB 011121: Radio Observations
  37. GRB 011121 J-Band Astrometry
  38. GRB011121: continued decay
  39. GRB 011121: Detection of Bright IR Counterpart
  40. GRB011121: possible redshift, continued decay
  41. GRB011121: fading behavior
  42. GRB011121: possible optical counterpart
  43. GRB011121: BeppoSAX-WFC refined positions
  44. IPN triangulation of GRB011121
  45. BEPPOSAX GRB011121
  46. GRB 011030: TNG K-band observation
  47. XRF011030: J and K band observations
  48. GRB011030, optical observation
  49. XRF011030: Chandra Observations
  50. GRB 011030: K-band observations
  51. GRB011030: Z-band observations
  52. GRB 011030 R band observations
  53. GRB 011030 I-band Observation
  54. The X-ray Flash 011030 ('GRB 011030')
  55. Non-triggered burst 011030 ("GRB 011030")
  56. The Radio Afterglow from the X-ray Rich GRB 011030
  57. GRB 010921: HST Detection of the Afterglow and Host Galaxy
  58. GRB 970828: HST Observations of the Host Galaxy
  59. GRB 000131: HST Detection of the Host Galaxy
  60. GRB 970828: HST Observations of the Host Galaxy
  61. GRB010921, optical observation
  62. GRB 011019 optical observation
  63. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  64. GRB011019: Subaru Optical Observations
  65. GRB 011030 I-band Observations
  66. GRB 011030 K-band Observations
  67. GRB010921, optical observations
  68. GRB 011030, WSRT radio observations
  69. GRB011030 - further refinement WFC position
  70. GRB 011030, Radio observations
  71. GRB011030: radio search
  72. GRB 011030, R-band observations
  73. X-ray rich GRB011030: BeppoSAX refined positions
  74. BeppoSAX ALERT: Possible X-ray rich GRB011030
  75. GRB 010921: Possible supernova component
  76. GRB011019: NEAT Optical Observations
  77. GRB011019: ROTSE-III optical observations
  78. GRB010921, optical observation at early time
  79. GRB 010921, I-band observations
  80. GRB011019: Optical observations
  81. GRB011019, optical observations -- correction
  82. GRB011019, optical observations
  83. GRB011019: A Faint, X-ray Rich GRB localized by HETE
  84. GRB010921: Spectroscopy of the Host Galaxy
  85. GRB 010921: The afterglow of HETE #1761
  86. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  87. Optical Observations of the field of HETE trigger #1793/GRB 011012?
  88. GRB010923 as seen by BeppoSAX GRBM
  89. GRB010928(=H1770): Localization of a Long GRB by HETE
  90. GRB010923(=H1764): A Short Duration GRB Detected by HETE
  91. GRB010921, negative optical observations
  92. GRB010921 field photometry
  93. GRB010921 Optical Observations
  94. GRB 010921 DPOSS Images Available
  95. IPN triangulation of GRB010921 (=H1761)
  96. H1761: A Bright GRB Detected by HETE
  97. HETE Trigger #1760 (GRB 010920B?): new optical source = asteroid
  98. HETE Trigger #1760 (GRB 010920B?): a new optical source
  99. HETE Trigger #1759 (GRB 010920?) optical observations
  100. GRB001109, Host Galaxy Astrometry

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