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"

20379 results found.

  1. CONCAM crude optical limits before and after GRB000926
  2. GRB 000926: Optical candidate
  3. Optical candidate for GRB000926
  4. IPN triangulation of GRB000926
  5. GRB 000911, BVRI field photometry
  6. GRB000911, Radio and Optical observations
  7. GRB000911: Optical observations
  8. IPN triangulation of GRB000910
  9. GRB000830, BVRI field photometry
  10. GRB000801, VLT-Antu R-band observations
  11. GRB000301C, UBVI optical observations
  12. GRB000801, Radio Observations
  13. GRB 991208 Host Galaxy Imaging
  14. IPN localization of GRB000730B
  15. IPN localization of GRB000730B
  16. GRB 990510: Possible detection of a host galaxy
  17. GRB 990510 Host Galaxy Discovery
  18. GRB 990712: Late time HST/STIS Observations
  19. GRB 991216, HST/STIS observations
  20. GRB000630, optical observations
  21. GRB000630, Revised BVRI Field Photometry
  22. GRB000630, Optical Observations
  23. GRB000630, optical observations
  24. GRB000630, optical observations
  25. GRB000630, BVRI Field Photometry
  26. GRB000630, optical observations
  27. GRB000630: Optical observations
  28. possible optical counterpart of GRB 000630
  29. GRB 000620, optical observations
  30. GRB000418, HST/STIS Observations
  31. GRB990123: Late-time HST/STIS observations of the host
  32. GRB000620, optical observations
  33. GRB000620 - Optical observations
  34. GRB000620 Optical observations
  35. GRB000620: BeppoSAX WFC and GRBM detection
  36. GRB000615, Radio observations
  37. GRB000607, optical observations
  38. GRB 000615: NIR further observations
  39. GRB000616 optical observations
  40. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  41. GRB000615, further R-band photometry
  42. GRB 000615: NIR observations
  43. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  44. GRB000615, R-band photometry
  45. GRB 000301C: Further Late-Time HST/STIS observations
  46. GRB000528: follow-up X-ray measurements and update of IPN annulus
  47. BeppoSAX X-ray transient/possible GRB000608
  48. GRB000604 - Optical observations
  49. GRB000604, optical observations
  50. GRB000528, optical observations at ESO
  51. GRB 000418: Detection of the Host Galaxy
  52. GRB000604, optical observations, comparison with DPOSS
  53. GRB000604 [IPN Position]
  54. GRB000528, Radio Observations
  55. X-ray Afterglow of GRB 000529
  56. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  57. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  58. GRB 000528 - WFC measurements
  59. GRB000529: BeppoSAX WFC position
  60. GRB000519, BVRI field photometry
  61. IPN triangulation of GRB000519
  62. GRB000508B, optical photometry
  63. GRB000508B, BVR field photometry
  64. Possible GRB-related phenomenon
  65. RXTE/ASM and IPN localization of GRB 000508B
  66. GRB000424, UBVRI field photometry
  67. GRB000418, UBVRI field photometry update
  68. GRB000424, optical observations
  69. GRB 000429, optical observation
  70. GRB 000429, UBVRI field photometry
  71. IPN localization of GRB000429
  72. GRB 000418, UBVRI field photometry
  73. GRB 000418, optical observation
  74. GRB 000418, Optical Observation
  75. IPN error box for GRB000418
  76. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  77. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  78. Budget cuts in BeppoSAX operations: impact on GRB observations
  79. GRB 000408, optical observations
  80. GRB 991208, UBVRI field photometry
  81. GRB000301c results
  82. GRB000408, lotis optical observations
  83. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  84. GRB000301C - Addendum to GCN 623
  85. GRB 000326: Optical Observations
  86. GRB000326, Radio observations
  87. GRB000326 [IPN Position]
  88. GRB000313, Radio observations
  89. GRB 000313 - optical transient in the BATSE error box
  90. GRB000301C - R photometry
  91. GRB 000307, Optical Observations
  92. GRB 000307, BVRI Field Photometry
  93. GRB 000301C: Optical Spectrum and Redshift
  94. GRB 000301C: Optical Spectrum and Redshift
  95. GRB 000301C: A Precise Redshift Determination
  96. GRB 000301C, Optical Observation
  97. GRB 000301C: HST/STIS CCD Imaging of the field
  98. GRB000301C, optical R-band observations
  99. GRB 000301C Optical Observations
  100. GRB 000301C: K' Observations

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