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"

27404 results found.

  1. GRB010222 R-BAND OBSERVATION
  2. GRB010214 follow-up from Hanle
  3. GRB 010222: Near-IR Observations
  4. GRB 010222: Optical Observations
  5. GRB010222: Optical decay slope
  6. GRB 010214, Optical Observations
  7. GRB010222, radio observations
  8. GRB010222, optical observations
  9. GRB010222: BeppoSAX/NFI Observations
  10. GRB010214B,Gamma Ray Observations
  11. GRB 010220, simultaneous optical observations
  12. GRB010220: BeppoSAX WFC and GRBM preliminary data
  13. GRB010214, candidate optical afterglow
  14. GRB010214, optical observations
  15. GRB010214: BeppoSAX WFC and GRBM preliminary data
  16. GRB 010214: X-Ray afterglow
  17. GRB 010214 optical observation
  18. GRB010213, Radio Observations
  19. J-Band Observation of GRB 010214.
  20. GRB010213, Near-IR observations
  21. Possible InfraRed Transient of GRB 010214.
  22. GRB 010214, optical observations
  23. GRB010213 detected by HETE
  24. IPN Status Report
  25. HETE Status
  26. IPN/RXTE TRIANGULATION OF GRB010126
  27. GRB010126 Optical Observations
  28. IPN TRIANGULATION OF GRB010126
  29. Optical Observations of GRB 001018 at Keck
  30. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  31. Optical observations of GRB 001018 with JCAM
  32. IPN TRIANGULATION OF GRB010115
  33. IPN TRIANGULATION OF GRB010109
  34. IPN TRIANGULATION OF GRB010109
  35. IPN triangulation of GRB010104
  36. IPN triangulation of GRB010103
  37. H band observation of GRB 001212
  38. IPN triangulation of GRB001219
  39. GRB 001212 Optical Observation
  40. GRB 001212 Optical Observation
  41. GRB 001212 possible OA in 2MASS
  42. IPN triangulation of GRB001212
  43. Confirmation of IPN position for GRB001204
  44. IPN triangulation of GRB001204 (short/hard)
  45. GRB001120, optical observations
  46. WSRT 4.8 GHz observations of GRB001109
  47. IPN triangulation of GRB001120
  48. GRB 001109: deep JHK upper limits
  49. GRB 001109 X-ray afterglow with BeppoSAX
  50. CORRECTION to XMM-Newton observation of GRB001025
  51. GRB001109, Radio observations
  52. GRB001105 BVRI field photometry correction
  53. GRB001105, BVRI field photometry
  54. IPN TRIANGULATION OF GRB001105
  55. GRB 001025B, Optical obervations
  56. GRB 991208: HST Imaging of the Host Galaxy
  57. GRB 001025B, I-band observations
  58. XMM-Newton observation of GRB001025
  59. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  60. CORRECTION TO IPN/RXTE ERROR BOX FOR GRB001025
  61. GRB001007: Optical observations
  62. ASM Localization of GRB 001025
  63. GRB001007, Radio observations
  64. GRB 001018, Possible Radio Afterglow
  65. GRB001018, Gamma Ray Observations
  66. IPN TRIANGULATION OF GRB001019
  67. IPN TRIANGULATION OF GRB001018
  68. IPN TRIANGULATION OF GRB 001017
  69. V,R,I band observations of GRB000926
  70. HETE positions added to GCN
  71. GRB000926 - Amateur Optical Observations
  72. CONCAM null result on GRB001005
  73. IPN triangulation of GRB001005
  74. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  75. GRB000926 - Optical observations
  76. GRB000926 - Optical observations
  77. GRB 000926, Optical Decay
  78. GRB000911: VLT infrared observation
  79. GRB 000926, Optical Observations
  80. GRB000926 K'-band Observation
  81. J and K band observations of GRB 000926
  82. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  83. CONCAM crude optical limits before and after GRB000926
  84. GRB 000926: Preliminary R-band Lightcurve
  85. Spectroscopic Redshift of GRB 000926
  86. GRB 000926: Optical candidate
  87. Optical candidate for GRB000926
  88. GRB 000911, BVRI field photometry
  89. GRB000911, Radio and Optical observations
  90. GRB000911: Optical observations
  91. GRB000830, BVRI field photometry
  92. GRB000210, Optical observations
  93. "Snapshot" afterglow IDs and GRB 000830
  94. GRB000730, Gamma Ray Observations
  95. GRB000812, Radio observations
  96. GRB000801, Gamma Ray Observations
  97. GRB000801, VLT-Antu R-band observations
  98. GRB 991208 Host Galaxy Imaging
  99. IPN localization of GRB000730B
  100. GRB 990510: Possible detection of a host galaxy

Advanced

Download all Circulars as a .tar.gz archive:
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