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"

35340 results found.

  1. GRB010214: BeppoSAX/NFI Observations
  2. GRB010213 (HETE) TAROT observations
  3. GRB 010214, optical observations
  4. BeppoSAX ALERT: GRB010214
  5. IPN Status Report
  6. HETE Status
  7. GRB010126 opt. obs.
  8. IPN/RXTE TRIANGULATION OF GRB010126
  9. GRB010126: CONCAM crude optical limits during GRB
  10. GRB010126, TNG R-band observations
  11. IPN TRIANGULATION OF GRB010126
  12. IPN/RXTE TRIANGULATION OF GRB010126
  13. GRB 010119, optical observations
  14. GRB010119: Optical observations
  15. Optical Observations of GRB 001018 at Keck
  16. IPN TRIANGULATION OF GRB010119 (SHORT/HARD)
  17. Optical observations of GRB 001018 with JCAM
  18. IPN TRIANGULATION OF GRB010115
  19. IPN TRIANGULATION OF GRB010109
  20. GRB010103, optical observations
  21. IPN triangulation of GRB010104
  22. IPN triangulation of GRB010103
  23. GRB 001204: Ks observations
  24. H band observation of GRB 001212
  25. GRB & BeppoSAX: ground operations restored back to 24 hrs a day
  26. IPN triangulation of GRB001219
  27. GRB 001212 Optical Observation
  28. GRB 001212 Optical Observation
  29. GRB 001212 optical observation
  30. GRB 001212 possible OA in 2MASS
  31. GRB 001212 possible OA
  32. IPN triangulation of GRB001212
  33. Confirmation of IPN position for GRB001204
  34. IPN triangulation of GRB001204 (short/hard)
  35. GRB 001105, further optical observations
  36. GRB001120: Gunn-i observations
  37. GRB001120: Optical observations
  38. GRB001109, optical observations
  39. GRB001120, optical observations
  40. IPN triangulation of GRB001120
  41. Optical/NIR observations of GRB001109
  42. GRB 001109: deep JHK upper limits
  43. GRB 001109 X-ray afterglow with BeppoSAX
  44. GRB001109: Optical observations
  45. GRB001109: BeppoSAX/NFI Observations
  46. GRB001109, R-band optical observations
  47. GRB001109, Radio observations
  48. BeppoSAX ALERT: GRB001109
  49. GRB001105 BVRI field photometry correction
  50. GRB001105, BVRI field photometry
  51. GRB 001105, R-band observation
  52. IPN TRIANGULATION OF GRB001105
  53. GRB 001025B, Optical obervations
  54. GRB 991208: HST Imaging of the Host Galaxy
  55. GRB000926: R-image of the host galaxy
  56. GRB 001025B, I-band observations
  57. GRB 001025 Optical Observations
  58. GRB 001025A, optical observation
  59. IPN TRIANGULATION OF GRB001025B (SHORT/HARD)
  60. IPN triangulation of GRB001025
  61. ASM Localization of GRB 001025
  62. GRB001007, Radio observations
  63. IPN TRIANGULATION OF GRB001020
  64. GRB001019, Optical Observations
  65. GRB 001018, Possible Radio Afterglow
  66. GRB001018, Gamma Ray Observations
  67. IPN TRIANGULATION OF GRB001019
  68. IPN TRIANGULATION OF GRB001018
  69. IPN TRIANGULATION OF GRB 001017
  70. GRB 000926: Improved Absorber Redshift
  71. V,R,I band observations of GRB000926
  72. The Likely Optical/Infrared Afterglow of GRB 001011
  73. HETE positions added to GCN
  74. BeppoSAX ALERT: GRB001011
  75. GRB 001007, BVR-band observations
  76. GRB000926 - Amateur Optical Observations
  77. CONCAM null result on GRB001005
  78. IPN triangulation of GRB001007
  79. GRB 000926 : the host galaxy
  80. IPN triangulation of GRB001005
  81. GRB 000926 Chandra Observation
  82. IPN triangulation of GRB 001004
  83. Public availability of BeppoSAX data of GRB000926
  84. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  85. GRB 000926, Optical Decay
  86. GRB000926 - Optical observations
  87. GRB000926 - Optical observations
  88. GRB 000926: optical observations
  89. GRB 000926, Optical Observations
  90. GRB000926 K'-band Observation
  91. GRB000926 : increasing optical decay slope
  92. GRB000926 optical observations
  93. GRB000926 - Optical observations
  94. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  95. J and K band observations of GRB 000926
  96. GRB 000926: Lightcurve Update and Predictions
  97. GRB 000926, optical observation by Oksanen (vsnet-grb)
  98. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  99. CONCAM crude optical limits before and after GRB000926
  100. GRB 000926: Preliminary R-band Lightcurve

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