Skip to main content
Circulars over Kafka event name backfill. 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"

24594 results found.

  1. GRB 981220:Optical Observations
  2. GRB 981226 optical observations
  3. GRB 981220
  4. GRB 981220, radio observations
  5. GRB981220 I-band Observations
  6. GRB 981220
  7. GRB 980326/Host Galaxy
  8. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  9. BeppoSAX NFI Observation of GRB980425
  10. GRB980329 R,I flux calibration and R,I,K upper limits
  11. GRB980425 Optical Follow-up
  12. GRB 980923 BATSE Observations
  13. SGR1900+14, BeppoSAX-GRBM observations
  14. GRB970508 optical observations
  15. GRB971214, association with a Galactic star?
  16. GRB980519, Optical Observations
  17. GRB980703 - BeppoSAX/GRBM detection
  18. GRB980703 optical photometry
  19. GRB 980703: BATSE Observations
  20. GRB980703 optical observations
  21. GRB980703: Radio transient
  22. GRB 980703: Spectrum of the proposed optical counterpart
  23. GRB980703 Transient Optical Follow-Up
  24. GRB980703: LOTIS observation at early times
  25. GRB980613 Optical Observations
  26. GRB980703 (I band observations)
  27. BeppoSAX NFI observations of GRB 980703
  28. GRB980519 observation report
  29. GRB980703 optical followup
  30. Radio observations of SGRs
  31. SGR1900+14 field optical observations
  32. GRB980613, optical observations
  33. GRB 980613: Optical transient and its host galaxy
  34. SGR1627-41, RXTE/ASM observations
  35. GRB 980613: Detection of the probable host galaxy
  36. Reduced error box of SGR 1627-41
  37. GRB 980613: BATSE Observations
  38. GRB 980613 Optical Observations
  39. GRB 980613 optical observations
  40. Discovery of a new SGR source, SGR1627-41
  41. GRB980613 Optical Observations
  42. GRB980613 observations from Palomar
  43. GRB 980613 optical/IR obs.
  44. GRB980613 Near Infra-Red Observations
  45. GRB971214 Secondary Standards
  46. GRB980519 Secondary Standards
  47. BATSE on-board GRB trigger change
  48. GRB 980519 Optical Observations
  49. GRB 980519
  50. GRB980519 optical observations
  51. GRB 980519 Optical Observations
  52. GRB980519 BATSE Observations
  53. GRB980519 Optical Observations
  54. GRB980519 Optical Observations
  55. GRB 980519 Optical Observations
  56. GRB980515, BeppoSAX IAUC to be submitted
  57. BSAX Observations of GRB980425 field
  58. IPN web site of GRBs
  59. GRB980425 BATSE observations
  60. SAX J0840.7+2248 Optical Observations
  61. GRB980425: optical obs.
  62. GRB980425: Radio Observations
  63. report on BSAX observations of GRB980425
  64. GRB 980329 ROSAT observation
  65. GRB980326 X-ray Observations
  66. GRB980326, optical observations
  67. GRB980326, optical observations
  68. GRB980329, Fading IR counterpart to radio source
  69. GRB980329 Keck K-band observations
  70. GRB980329 sub-millimeter observations
  71. GRB980329 optical observations
  72. GRB980329 near-IR observations
  73. GRB980329 near-IR observations
  74. GRB980326 optical observations
  75. GRB980329 optical observations
  76. GRB980329 VLA observations
  77. GRB980329 optical observations
  78. GRB980329 optical observations
  79. GRB980326 optical observations
  80. GRB980326 optical observations
  81. Optical Observations of GRB 970508
  82. Near-IR follow-up on GRB 971227
  83. Optical Observations of the GRB 971227 field
  84. Optical Observations on GRB 971227
  85. GRB971227: Plaskett R-band observations
  86. GRB 971227: Optical clarifications
  87. GRB971227: Further CAHA R-band images
  88. GRB971227: LOTIS observations
  89. GRB971214: Optical Observations and Calibrations
  90. GRB 971214: Optical Observations
  91. Radio Observations of GRB 971214 at the VLA
  92. GRB 971024: Refined analysis by USNOFS Observations
  93. GRB 971024: KPNO Optical Observations
  94. GRB 970828: Palomar Observations

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