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"

32502 results found.

  1. GRB010214 follow-up from Hanle
  2. GRB 010222: Near-IR Observations
  3. GRB 010222: Optical Observations
  4. GRB 010222, Decay Slope Confirmed
  5. GRB010222: Another absorption line system
  6. GRB010222: Optical decay slope
  7. GRB 010214, Optical Observations
  8. GRB010222: Sub-millimeter detection
  9. GRB010222: R-band fading behavior
  10. GRB010222: Optical Observations
  11. GRB010222, radio observations
  12. GRB010222, optical observations
  13. GRB010222: BeppoSAX/NFI Observations
  14. Redshift of the Optical Transient of GRB010222
  15. GRB010222: possible optical counterpart
  16. GRB010222
  17. GRB010222: BeppoSAX refined position
  18. ALERT: GRB010222: the brightest GRB observed by BeppoSAX
  19. GRB010220, Radio and Optical Observations
  20. GRB 010220, simultaneous optical observations
  21. GRB010220: BeppoSAX WFC and GRBM preliminary data
  22. GRB010214, candidate optical afterglow
  23. GRB010214, optical observations
  24. GRB010214: BeppoSAX WFC and GRBM preliminary data
  25. GRB 010214: X-Ray afterglow
  26. GRB 010214, Optical Observations
  27. GRB 010214 optical observation
  28. GRB010213, Radio Observations
  29. GRB010213 Optical Observation
  30. GRB010213, Radio Observations
  31. J-Band Observation of GRB 010214.
  32. GRB010214, Radio Observations
  33. GRB010214, optical observations
  34. GRB010213, optical observations
  35. Possible InfraRed Transient of GRB 010214.
  36. GRB010214 Optical Observation
  37. GRB010213 (HETE) TAROT observations
  38. GRB 010214, optical observations
  39. IPN Status Report
  40. HETE Status
  41. GRB010126 opt. obs.
  42. IPN/RXTE TRIANGULATION OF GRB010126
  43. GRB010126: CONCAM crude optical limits during GRB
  44. GRB010126, TNG R-band observations
  45. GRB010126 Optical Observations
  46. GRB010126 optical observations
  47. GRB010126: Optical observations
  48. IPN/RXTE TRIANGULATION OF GRB010126
  49. GRB 010119, optical observations
  50. GRB010119: Optical observations
  51. Optical Observations of GRB 001018 at Keck
  52. GRB010119, Radio observations
  53. Optical observations of GRB 001018 with JCAM
  54. IPN TRIANGULATION OF GRB010109
  55. GRB 001204: Ks observations
  56. H band observation of GRB 001212
  57. GRB 001212 Optical Observation
  58. GRB 001212 Optical Observation
  59. GRB 001212 optical observation
  60. GRB 001212 possible OA in 2MASS
  61. GRB 001212 possible OA
  62. GRB001204: Optical observations
  63. Confirmation of IPN position for GRB001204
  64. GRB001204, Radio observations
  65. GRB 001105, further optical observations
  66. GRB001120: Gunn-i observations
  67. GRB001109, optical observations
  68. WSRT 4.8 GHz observations of GRB001109
  69. Optical/NIR observations of GRB001109
  70. GRB 001109: deep JHK upper limits
  71. GRB 001109 X-ray afterglow with BeppoSAX
  72. CORRECTION to XMM-Newton observation of GRB001025
  73. GRB001109: Optical observations
  74. GRB001109, R-band optical observations
  75. GRB001109, Radio observations
  76. GRB001105 BVRI field photometry correction
  77. GRB001105, BVRI field photometry
  78. GRB 001105, R-band observation
  79. GRB 991208: HST Imaging of the Host Galaxy
  80. GRB000926: R-image of the host galaxy
  81. GRB 001025B, I-band observations
  82. XMM-Newton observation of GRB001025
  83. GRB001025B, Radio observations
  84. GRB 001025 Optical Observations
  85. GRB 001025A, optical observation
  86. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  87. IPN triangulation of GRB001025
  88. GRB001007: Optical observations
  89. GRB001007, Radio observations
  90. GRB 001018, Possible Radio Afterglow
  91. CORRECTION TO PEAK FLUX OF GRB001018
  92. GRB 000926: Improved Absorber Redshift
  93. V,R,I band observations of GRB000926
  94. The Likely Optical/Infrared Afterglow of GRB 001011
  95. HETE positions added to GCN
  96. GRB 001007, BVR-band observations
  97. GRB001007: Optical observations
  98. CONCAM null result on GRB001005
  99. GRB 000926 : the host galaxy
  100. GRB 000926 Chandra Observation

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