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"
  1. GRB000620 Optical observations
  2. IPN annulus for GRB000620
  3. GRB000620: BeppoSAX WFC and GRBM detection
  4. GRB000615, Radio observations
  5. GRB000607, optical observations
  6. GRB 000615: NIR further observations
  7. GRB000620: refined BeppoSAX/WFC coordinates
  8. BeppoSAX ALERT: GRB000620
  9. GRB000620: BeppoSAX Alert
  10. GRB990123, HST/STIS observations of the host galaxy
  11. GRB000616 optical observations
  12. GRB 000615, near-infrared observations
  13. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  14. GRB000616 [IPN Position]
  15. GRB000615B [IPN Position]
  16. GRB000615, further R-band photometry
  17. GRB 000615: NIR observations
  18. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  19. GRB000615, R-band photometry
  20. GRB000615: BeppoSAX refined coordinates
  21. GRB980425, HST/STIS observations of the host galaxy
  22. GRB000615: BeppoSAX GRB Alert
  23. The Hosts of GRB 980703 and GRB 971214
  24. GRB 000301C: Further Late-Time HST/STIS observations
  25. GRB000528: follow-up X-ray measurements and update of IPN annulus
  26. Optical Follow-up of GRB000529 Error Box
  27. GRB980519, HST/STIS observations of the host galaxy
  28. GRB000607, Radio Observations
  29. BeppoSAX X-ray transient/possible GRB000608
  30. GRB000604 optical non-detection
  31. GRB000604 - Optical observations
  32. GRB000607, A SHORT, HARD BURST
  33. GRB000604, optical observations
  34. GRB000528, optical observations at ESO
  35. GRB 000604 optical observations
  36. GRB 000418: Detection of the Host Galaxy
  37. GRB000604, optical observations, comparison with DPOSS
  38. GRB000604 [IPN Position]
  39. GRB000528, Radio Observations
  40. X-ray Afterglow of GRB 000529
  41. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  42. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  43. GRB000529: Optical Observations
  44. IPN localization and time history of GRB000528
  45. New IPN localization of GRB000529
  46. GRB000519: Optical observations
  47. IPN localization of GRB000529
  48. GRB 000528 - WFC measurements
  49. GRB000529: BeppoSAX WFC position
  50. GRB000528: BeppoSAX GRBM observations
  51. GRB 000528 Optical Observations
  52. GRB000519, BVRI field photometry
  53. IPN triangulation of GRB000519
  54. IPN triangulation of GRB000516
  55. Re: GRB000508B : Optical observations
  56. GRB 000418, Optical observation
  57. GRB000508B, optical photometry
  58. GRB000508B, BVR field photometry
  59. Possible GRB-related phenomenon
  60. RXTE/ASM and IPN localization of GRB 000508B
  61. GRB000424, UBVRI field photometry
  62. GRB 000424 Optical Observations
  63. GRB000418, UBVRI field photometry update
  64. The redshift of GRB 000418
  65. GRB000424, optical observations
  66. GRB 000429, optical observation
  67. GRB 000429, UBVRI field photometry
  68. IPN localization of GRB000429
  69. GRB 000418, UBVRI field photometry
  70. GRB000418, Radio detection
  71. GRB000418, K'-band photometry
  72. GRB 000418, Optical Observation
  73. GRB 000418, optical observation
  74. GRB000424 Optical Observations
  75. GRB 000418, Optical Observation
  76. GRB000424, optical observations
  77. GRB000424, optical observations
  78. GRB 000424, Optical Observations
  79. GRB 000418, Optical Observation
  80. GRB000418, near-infrared observations
  81. BeppoSAX GRB000424
  82. Correction to IPN error box for GRB000419
  83. IPN error box for GRB000418
  84. GRB000419 [IPN Position]
  85. GRB000416 Optical Observations
  86. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  87. GRB000416 BRJK observations
  88. 1SAXJ1715.0-7134 refined position
  89. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  90. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  91. Budget cuts in BeppoSAX operations: impact on GRB observations
  92. GRB 000408, optical observations
  93. Refined IPN error box for GRB000408
  94. GRB 991208, UBVRI field photometry
  95. GRB000301c results
  96. GRB000408: Optical CCD Observations from MIRO
  97. GRB000408, lotis optical observations
  98. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  99. GRB000408 [IPN Position]
  100. GRB000326 Optical 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