Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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. GRB970508 optical observations
  2. GRB971214, association with a Galactic star?
  3. Optical Observations of the Host Galaxy of GRB 980519
  4. GRB980519, Optical Observations
  5. GRB980703, Host galaxy multicolor photometry
  6. GRB980703 - BeppoSAX/GRBM detection
  7. GRB 980703 (NFI observations)
  8. GRB980703 optical photometry
  9. GRB 980703: BATSE Observations
  10. GRB980703 optical observations
  11. GRB980703: Radio transient
  12. GRB980703 H-band Observations
  13. GRB 980703: Spectrum of the proposed optical counterpart
  14. RXTE Observation of GRB 980706
  15. GRB980703: Spectrum of the proposed optical counterpart
  16. GRB980703 Transient Optical Follow-Up
  17. GRB980703: LOTIS observation at early times
  18. GRB980613 Optical Observations
  19. GRB 980703
  20. GRB980703 (I band observations)
  21. GRB 980703 H-band Observations
  22. GRB980703 (optical R observations)
  23. GRB980706
  24. GRB980703: radio source/optical transient
  25. BeppoSAX NFI observations of GRB 980703
  26. GRB 980703: ASM Position & Intensity
  27. GRB980703
  28. GRB980519 observation report
  29. GRB980703 optical followup
  30. SGR1627-41
  31. Radio observations of SGRs
  32. SGR1900+14 field optical observations
  33. GRB 980613 Near-IR observations
  34. GRB980613, optical observations
  35. GRB 980613: Optical transient and its host galaxy
  36. SGR1627-41, RXTE/ASM observations
  37. SGR1627-41, Refined IPN annulus location
  38. GRB 980613: Detection of the probable host galaxy
  39. Reduced error box of SGR 1627-41
  40. GRB 980613: BATSE Observations
  41. SGR1627-41, BeppoSAX-GRBM detections
  42. SGR 1627-41
  43. GRB 980613 Optical Observations
  44. GRB 980613 optical observations
  45. Discovery of a new SGR source, SGR1627-41
  46. GRB980613 Optical Observations
  47. GRB980613 observations from Palomar
  48. GRB980613 BeppoSAX-NFI follow up
  49. GRB 980613 new optical/IR observations
  50. GRB 980613 optical/IR obs.
  51. GRB980613 Near Infra-Red Observations
  52. GRB980611
  53. GRB980613, BeppoSAX WFC positions
  54. GRB971214 Secondary Standards
  55. SGR 1900+14
  56. GRB980519 Secondary Standards
  57. SGR1900+14
  58. SGR1900+14
  59. BATSE on-board GRB trigger change
  60. GRB 980519 Optical Observations
  61. GRB980519 optical observations
  62. GRB980519 I-band observations
  63. GRB 980519
  64. GRB980519 optical observations
  65. GRB 980519 Optical Observations
  66. GRB980519 BATSE Observations
  67. GRB970519, optical follow-up at Schmidt Calern
  68. GRB980519 optical observations
  69. GRB980519 Optical Observations
  70. GRB980519 Optical Observations
  71. GRB980519 IPN POSITION
  72. GRB980519 Optical Observations
  73. GRB 980519 Optical Observations
  74. GRB980519 optical observations
  75. GRB980515, BeppoSAX IAUC to be submitted
  76. BATSE on-board GRB trigger change
  77. GRB980519, BeppoSAX-WFC updated position
  78. GRB980519, BeppoSAX-WFC position
  79. GRB980515: SAX-WFC updated position
  80. BeppoSAX GRB ALERT: updated position of grb980515
  81. GRB 980425 Radio Light Curve
  82. GRB 980425 Brightness Temperature
  83. BSAX Observations of GRB980425 field
  84. IPN web site of GRBs
  85. GRB980425 BATSE observations
  86. SAX J0840.7+2248 Optical Observations
  87. GRB 980425 optical observations
  88. GRB980425: optical obs.
  89. GRB980425: Radio Observations
  90. GRB 980425 optical observations
  91. report on BSAX observations of GRB980425
  92. GRB 980425 optical observations
  93. GRB 980329 ROSAT observation
  94. GRB980326 X-ray Observations
  95. GRB980326, optical observations
  96. GRB980326, optical observations
  97. GRB980329, Fading IR counterpart to radio source
  98. GRByymmdd, Announcement of automation
  99. GRB980326 IPN annulus
  100. GRB980329

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