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"

20354 results found.

  1. GRB 010222 Kyoto optical observation
  2. GRB 010222 BV optical observations
  3. GRB010222 R-BAND OBSERVATION
  4. GRB010214 follow-up from Hanle
  5. GRB 010222: Near-IR Observations
  6. GRB 010222: Optical Observations
  7. GRB010222, radio observations
  8. GRB010222, optical observations
  9. GRB010220, Radio and Optical Observations
  10. GRB 010220, simultaneous optical observations
  11. GRB010220: BeppoSAX WFC and GRBM preliminary data
  12. GRB010214, optical observations
  13. BeppoSAX GRB010220: refined position
  14. GRB010214: BeppoSAX WFC and GRBM preliminary data
  15. GRB 010214: X-Ray afterglow
  16. GRB 010214 optical observation
  17. J-Band Observation of GRB 010214.
  18. GRB010213, Near-IR observations
  19. Possible InfraRed Transient of GRB 010214.
  20. GRB010213 (HETE) TAROT observations
  21. GRB010213 detected by HETE
  22. IPN Status Report
  23. HETE Status
  24. GRB010126 Optical Observations
  25. IPN TRIANGULATION OF GRB010126
  26. Optical Observations of GRB 001018 at Keck
  27. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  28. Optical observations of GRB 001018 with JCAM
  29. IPN TRIANGULATION OF GRB010115
  30. IPN TRIANGULATION OF GRB010109
  31. IPN TRIANGULATION OF GRB010109
  32. IPN triangulation of GRB010104
  33. IPN triangulation of GRB010103
  34. IPN triangulation of GRB001219
  35. GRB 001212 Optical Observation
  36. GRB 001212 Optical Observation
  37. GRB 001212 possible OA
  38. IPN triangulation of GRB001212
  39. Confirmation of IPN position for GRB001204
  40. IPN triangulation of GRB001204 (short/hard)
  41. GRB001120, optical observations
  42. WSRT 4.8 GHz observations of GRB001109
  43. IPN triangulation of GRB001120
  44. GRB 001109: deep JHK upper limits
  45. GRB 001109 X-ray afterglow with BeppoSAX
  46. CORRECTION to XMM-Newton observation of GRB001025
  47. GRB001109, Radio observations
  48. BeppoSAX ALERT: GRB001109
  49. GRB001105 BVRI field photometry correction
  50. GRB001105, BVRI field photometry
  51. IPN TRIANGULATION OF GRB001105
  52. GRB 001025B, Optical obervations
  53. GRB 991208: HST Imaging of the Host Galaxy
  54. GRB 001025B, I-band observations
  55. XMM-Newton observation of GRB001025
  56. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  57. GRB001007: Optical observations
  58. ASM Localization of GRB 001025
  59. GRB001007, Radio observations
  60. IPN TRIANGULATION OF GRB001019
  61. IPN TRIANGULATION OF GRB001018
  62. IPN TRIANGULATION OF GRB 001017
  63. V,R,I band observations of GRB000926
  64. HETE positions added to GCN
  65. GRB 001007, BVR-band observations
  66. GRB000926 - Amateur Optical Observations
  67. CONCAM null result on GRB001005
  68. IPN triangulation of GRB001007
  69. GRB000926 - Optical observations
  70. GRB000926 - Optical observations
  71. GRB 000926, Optical Observations
  72. GRB000926 K'-band Observation
  73. J and K band observations of GRB 000926
  74. GRB000911 Optical Observations
  75. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  76. CONCAM crude optical limits before and after GRB000926
  77. GRB 000926: Optical candidate
  78. Optical candidate for GRB000926
  79. IPN triangulation of GRB000926
  80. GRB 000911, BVRI field photometry
  81. GRB000911, Radio and Optical observations
  82. GRB000911: Optical observations
  83. IPN triangulation of GRB000910
  84. GRB000830, BVRI field photometry
  85. GRB000801, VLT-Antu R-band observations
  86. GRB000301C, UBVI optical observations
  87. GRB000801, Radio Observations
  88. GRB 991208 Host Galaxy Imaging
  89. IPN localization of GRB000730B
  90. IPN localization of GRB000730B
  91. GRB 990510: Possible detection of a host galaxy
  92. GRB 990510 Host Galaxy Discovery
  93. GRB 990712: Late time HST/STIS Observations
  94. GRB 991216, HST/STIS observations
  95. GRB000630, optical observations
  96. GRB000630, Revised BVRI Field Photometry
  97. GRB000630, Optical Observations
  98. GRB000630, optical observations
  99. GRB000630, optical observations
  100. GRB000630, BVRI Field Photometry

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