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"

15556 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. GRB010220, Radio and Optical Observations
  18. GRB 010220, simultaneous optical observations
  19. GRB010214, candidate optical afterglow
  20. GRB010214, optical observations
  21. GRB 010214, Optical Observations
  22. GRB 010214 optical observation
  23. GRB010213 Optical Observation
  24. GRB010213, Radio Observations
  25. GRB010214, optical observations
  26. GRB010213, optical observations
  27. GRB010214 Optical Observation
  28. GRB 010214, optical observations
  29. GRB010213 detected by HETE
  30. HETE Status
  31. GRB010126: CONCAM crude optical limits during GRB
  32. GRB010126, TNG R-band observations
  33. GRB010126 Optical Observations
  34. GRB010126 optical observations
  35. GRB010126: Optical observations
  36. GRB 010119, optical observations
  37. GRB010119: Optical observations
  38. Optical Observations of GRB 001018 at Keck
  39. Optical observations of GRB 001018 with JCAM
  40. GRB010103, optical observations
  41. GRB 001212 Optical Observation
  42. GRB 001212 Optical Observation
  43. GRB 001212 optical observation
  44. GRB 001212 possible OA in 2MASS
  45. GRB 001212 possible OA
  46. GRB001204: Optical observations
  47. GRB 001105, further optical observations
  48. GRB001120: Gunn-i observations
  49. GRB001120: Optical observations
  50. GRB001109, optical observations
  51. GRB001120, optical observations
  52. Optical/NIR observations of GRB001109
  53. GRB 001109: deep JHK upper limits
  54. GRB001109: Optical observations
  55. GRB001109, R-band optical observations
  56. GRB001109, Radio observations
  57. GRB001105, BVRI field photometry
  58. GRB 001105, R-band observation
  59. GRB 001025B, Optical obervations
  60. GRB 991208: HST Imaging of the Host Galaxy
  61. GRB000926: R-image of the host galaxy
  62. GRB 001025 Optical Observations
  63. GRB 001025A, optical observation
  64. GRB001007: Optical observations
  65. GRB001007, Radio observations
  66. GRB001019, Optical Observations
  67. GRB 000926: Improved Absorber Redshift
  68. The Likely Optical/Infrared Afterglow of GRB 001011
  69. GRB 001007, BVR-band observations
  70. GRB000926 - Amateur Optical Observations
  71. GRB001007: Optical observations
  72. CONCAM null result on GRB001005
  73. GRB 000926 : the host galaxy
  74. GRB 000926 Chandra Observation
  75. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  76. GRB000926 - Optical observations
  77. GRB000926 - Optical observations
  78. GRB 000926, Optical Decay
  79. GRB000911: VLT infrared observation
  80. GRB000926 - Optical observations
  81. GRB000926 - Optical observations
  82. GRB 000926: optical observations
  83. GRB 000926, Optical Observations
  84. GRB000926 - Optical observations
  85. GRB000911: optical VLT observations
  86. GRB000926 K'-band Observation
  87. GRB000926 : increasing optical decay slope
  88. GRB000926 optical observations
  89. GRB000926 - Optical observations
  90. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  91. J and K band observations of GRB 000926
  92. GRB000911 Optical Observations
  93. GRB 000926: Lightcurve Update and Predictions
  94. GRB 000926, optical observation by Oksanen (vsnet-grb)
  95. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  96. GRB000926: Optical observations
  97. CONCAM crude optical limits before and after GRB000926
  98. GRB 000926: Preliminary R-band Lightcurve
  99. GRB 000926 HST/Chandra TOO Status
  100. Spectroscopic Redshift of GRB 000926

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