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"

24606 results found.

  1. IPN localization of GRB000730B
  2. GRB 990510: Possible detection of a host galaxy
  3. GRB 990510 Host Galaxy Discovery
  4. IPN localization of GRB000727
  5. GRB 990712: Late time HST/STIS Observations
  6. GRB 991216, HST/STIS observations
  7. GRB000620, Radio Observations
  8. GRB000630, optical observations
  9. GRB000630, Revised BVRI Field Photometry
  10. GRB000630, Optical Observations
  11. GRB000630, optical observations
  12. GRB000630, optical observations
  13. GRB000630, BVRI Field Photometry
  14. GRB000630, optical observations
  15. GRB000630: Optical observations
  16. GRB000630, Radio Observations
  17. possible optical counterpart of GRB 000630
  18. GRB 000620, optical observations
  19. GRB000418, HST/STIS Observations
  20. GRB990123: Late-time HST/STIS observations of the host
  21. GRB000620, optical observations
  22. GRB000615: H-band observations
  23. GRB990308, HST/STIS observations of the host galaxy
  24. GRB000620 - Optical observations
  25. GRB000620 Optical observations
  26. GRB000620: BeppoSAX WFC and GRBM detection
  27. GRB000607, optical observations
  28. GRB 000615: NIR further observations
  29. GRB990123, HST/STIS observations of the host galaxy
  30. GRB000616 optical observations
  31. GRB 000615, near-infrared observations
  32. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  33. GRB000615, further R-band photometry
  34. GRB 000615: NIR observations
  35. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  36. GRB000615, R-band photometry
  37. The Hosts of GRB 980703 and GRB 971214
  38. GRB 000301C: Further Late-Time HST/STIS observations
  39. GRB000528: follow-up X-ray measurements and update of IPN annulus
  40. GRB980519, HST/STIS observations of the host galaxy
  41. GRB000604 optical non-detection
  42. GRB000604 - Optical observations
  43. GRB000604, optical observations
  44. GRB000528, optical observations at ESO
  45. GRB 000604 optical observations
  46. GRB 000418: Detection of the Host Galaxy
  47. GRB000604, optical observations, comparison with DPOSS
  48. GRB000528, Radio Observations
  49. X-ray Afterglow of GRB 000529
  50. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  51. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  52. GRB 000528 - WFC measurements
  53. GRB000519, BVRI field photometry
  54. IPN triangulation of GRB000519
  55. GRB000508B, optical photometry
  56. GRB000508B, BVR field photometry
  57. Possible GRB-related phenomenon
  58. RXTE/ASM and IPN localization of GRB 000508B
  59. GRB000424, UBVRI field photometry
  60. GRB000418, UBVRI field photometry update
  61. GRB000424, optical observations
  62. GRB 000429, optical observation
  63. GRB 000429, UBVRI field photometry
  64. GRB 000418, UBVRI field photometry
  65. GRB 000418, optical observation
  66. GRB 000418, Optical Observation
  67. GRB000418, near-infrared observations
  68. Correction to IPN error box for GRB000419
  69. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  70. GRB000416 BRJK observations
  71. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  72. GRB 000408, optical observations
  73. GRB 991208, UBVRI field photometry
  74. GRB000408, lotis optical observations
  75. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  76. GRB000301C - Addendum to GCN 623
  77. GRB 000323, optical observations
  78. GRB 000326: Optical Observations
  79. GRB000326, Radio observations
  80. GRB000313, Radio observations
  81. GRB 000313 - optical transient in the BATSE error box
  82. GRB 000307, Optical Observations
  83. GRB 000307, BVRI Field Photometry
  84. GRB 000301C: A Precise Redshift Determination
  85. GRB 000301C, Optical Observation
  86. GRB 000301C: HST/STIS CCD Imaging of the field
  87. IPN error box for GRB000307
  88. GRB000301C, optical R-band observations
  89. GRB 000301C Optical Observations
  90. GRB 000301C: K' Observations
  91. GRB000301C OT candidate optical observations
  92. GRB000301C - Host galaxy not detected in R (?)
  93. Optical observations of GRB000301c
  94. GRB000301C, Radio observations
  95. GRB000301C, Radio observations
  96. GRB000301C, near-infrared observations (JHK' imaging)
  97. GRB 000301c near-IR observations
  98. GRB 000301C, UBVRI field photometry
  99. GRB 000301C: OT confirmed
  100. GRB000301c optical 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