Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

34289 results found.

  1. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  2. IPN error box for GRB990527
  3. Late Afterglows of GRBs 990510, 990123
  4. X-ray/GRB 1SAX J0835.9+5118, TNG V and R observations
  5. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  6. X-ray/GRB 1SAX J0835.9+5118, Optical Observations
  7. GRB 990506 optical observation
  8. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  9. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  10. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  11. X-ray/GRB 1SAX J0835.9+5118, Optical Observation
  12. radio observations of X-ray/GRB transient field
  13. optical observation of the X-ray/GRB transient SAX J0835.9+5118
  14. Optical report on X-ray/GRB transient
  15. radio detection of X-ray/GRB transient
  16. BeppoSAX: A new fast X-ray transient
  17. GRB 990510: optical observations
  18. GRB990510: photometric and spectroscopic observations with the VLT
  19. GRB 990510: optical linear polarization
  20. GRB 990510: optical observations
  21. GRB990510, VI observations
  22. GRB 990506 R band observations
  23. GRB990510: X-ray afterglow
  24. GRB 990510: optical observation
  25. VLT spectrum of GRB990510
  26. GRB 990510: Broad Band Break
  27. GRB 990510: BATSE Observations
  28. GRB 990510 Optical Observations
  29. GRB 990510, BVI photometry
  30. GRB 990510 optical observations
  31. GRB 990510: BeppoSAX/GRBM observations
  32. GRB990510 optical observations
  33. GRB 990510 optical observations
  34. GRB 990510 optical observations
  35. Galactic extinction towards GRB 990510
  36. GRB 990510 optical observations
  37. IPN localization of GRB990510
  38. GRB 990506 Radio Observations
  39. GRB 990123, optical monitoring
  40. GRB 990506: BATSE Observations
  41. GRB 990506, optical observations
  42. GRB 990510: Final BeppoSAX-WFC Coordinates
  43. GRB 990506, Optical Observations
  44. GRB 990506 optical observations
  45. GRB 990506 optical observations
  46. GRB 990506, optical observations
  47. GRB990506 observation plan
  48. Refined IPN error box for GRB990506
  49. GRB 990506: Limits on the possible optical transient
  50. GRB 990506, armchair astronomy
  51. GRB 990506, optical observations from +1 to +3 hours
  52. GRB 990506, optical observations
  53. GRB990506 observation plan
  54. New IPN/RXTE error box for GRB990506
  55. IPN localization for GRB990506
  56. GRB 970228: Redshift and properties of the host galaxy
  57. IPN localization of GRB990427
  58. GRB981220 VLBA observations
  59. GRB990321 REFINED IPN ANNULUS
  60. GRB990323 PRECISE IPN POSITION
  61. GRB990321 IPN TRIANGULATION
  62. GRB 990316 Optical Observations
  63. GRB 990316, Radio observations
  64. GRB 990316, Optical observations
  65. GRB990316, Optical observations
  66. GRB 990316 optical observations
  67. GRB990316: simultaneous optical observation
  68. ASM/IPN error box for GRB 990308 (BATSE #7457)
  69. GRB990308 not a new SGR
  70. GRB 990308a and GRB 990308b
  71. GRB990308 (Trig. 7457), optical observations
  72. GRB981220, IPN localization
  73. GRB 981220, radio observations
  74. GRB 990123, Field Photometry
  75. GRB 990217 Optical Observations
  76. GRB 990217, radio observations
  77. Optical Observations of GRB990217
  78. GRB990123: Caltech STIS Photometry and Images
  79. GRB990123 observations
  80. GRB990123, Optical Observation
  81. GRB 990123: Discovery of the Probable Host Galaxy
  82. GRB 990123: Reduced HST Images
  83. For Immediate Posting to GCN - HST Data GRB 990123 Available
  84. GRB19990123 observations
  85. GRB 990123: BVRI standards in the field
  86. GRB 990123: Updated Keck Spectroscopy Results
  87. GRB981220, field photometry
  88. GRB 990123 NOT Spectrum Update
  89. GRB990123, Optical observation
  90. GRB990123, is the "radio flare" due to an inhomogeneous medium?
  91. GRB 990123: Publicly available reduced HST images
  92. GRB990123, Upcoming HST Service Observations
  93. GRB 990123: New Constraints on Possible Foreground Galaxies
  94. GRB990123 Optical Observations
  95. GRB990123, Probability of gravitational lensing
  96. GRB 990123: Detection of the IR Transient, and the Light Curve Fits
  97. GRB 990123: Continued Radio Observations
  98. GRB990123, Preliminary Lens Search Results
  99. GRB 990123: Correction to GCN 230 - C.A. Young added to author list
  100. On the Lensing Interpretation of GRB 990123

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