Skip to main content
New! BOOM Notices and Schema v7.0.0. 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"

44618 results found.

  1. GRB990123, HST/STIS observations of the host galaxy
  2. GRB000616 optical observations
  3. GRB 000615, near-infrared observations
  4. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  5. GRB000616 [IPN Position]
  6. GRB000615B [IPN Position]
  7. GRB000615, further R-band photometry
  8. GRB 000615: NIR observations
  9. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  10. GRB000615, R-band photometry
  11. GRB000615: BeppoSAX refined coordinates
  12. GRB980425, HST/STIS observations of the host galaxy
  13. GRB000615: BeppoSAX GRB Alert
  14. The Hosts of GRB 980703 and GRB 971214
  15. GRB 000301C: Further Late-Time HST/STIS observations
  16. GRB000528: follow-up X-ray measurements and update of IPN annulus
  17. Optical Follow-up of GRB000529 Error Box
  18. GRB980519, HST/STIS observations of the host galaxy
  19. GRB000607, Radio Observations
  20. BeppoSAX X-ray transient/possible GRB000608
  21. GRB000604 optical non-detection
  22. GRB000604 - Optical observations
  23. GRB000607, A SHORT, HARD BURST
  24. GRB000604, optical observations
  25. GRB000528, optical observations at ESO
  26. GRB 000604 optical observations
  27. GRB 000418: Detection of the Host Galaxy
  28. GRB000604, optical observations, comparison with DPOSS
  29. GRB000604 [IPN Position]
  30. GRB000528, Radio Observations
  31. X-ray Afterglow of GRB 000529
  32. GRB000529: BeppoSAX NFI follow-up preliminary analysis
  33. GRB000528: BeppoSAX NFI follow-up preliminary analysis
  34. GRB000529: Optical Observations
  35. IPN localization and time history of GRB000528
  36. New IPN localization of GRB000529
  37. GRB000519: Optical observations
  38. IPN localization of GRB000529
  39. GRB 000528 - WFC measurements
  40. GRB000529: BeppoSAX WFC position
  41. GRB000528: BeppoSAX GRBM observations
  42. GRB 000528 Optical Observations
  43. GRB000519, BVRI field photometry
  44. IPN triangulation of GRB000519
  45. IPN triangulation of GRB000516
  46. Re: GRB000508B : Optical observations
  47. GRB 000418, Optical observation
  48. GRB000508B, optical photometry
  49. GRB000508B, BVR field photometry
  50. Possible GRB-related phenomenon
  51. RXTE/ASM and IPN localization of GRB 000508B
  52. GRB000424, UBVRI field photometry
  53. GRB 000424 Optical Observations
  54. GRB000418, UBVRI field photometry update
  55. The redshift of GRB 000418
  56. GRB000424, optical observations
  57. GRB 000429, optical observation
  58. GRB 000429, UBVRI field photometry
  59. IPN localization of GRB000429
  60. GRB 000418, UBVRI field photometry
  61. GRB000418, Radio detection
  62. GRB000418, K'-band photometry
  63. GRB 000418, Optical Observation
  64. GRB 000418, optical observation
  65. GRB000424 Optical Observations
  66. GRB 000418, Optical Observation
  67. GRB000424, optical observations
  68. GRB000424, optical observations
  69. GRB 000424, Optical Observations
  70. GRB 000418, Optical Observation
  71. GRB000418, near-infrared observations
  72. BeppoSAX GRB000424
  73. Correction to IPN error box for GRB000419
  74. IPN error box for GRB000418
  75. GRB000419 [IPN Position]
  76. GRB000416 Optical Observations
  77. BATSE observations of FXT/GRB 000416 = 1SAXJ1715.0-7134
  78. GRB000416 BRJK observations
  79. 1SAXJ1715.0-7134 refined position
  80. RE: Budget cuts in BeppoSAX operations: impact on GRB observation
  81. X-ray burst or X-ray rich GRB 000416 observed by BeppoSAX
  82. Budget cuts in BeppoSAX operations: impact on GRB observations
  83. GRB 000408, optical observations
  84. Refined IPN error box for GRB000408
  85. GRB 991208, UBVRI field photometry
  86. GRB000301c results
  87. GRB000408: Optical CCD Observations from MIRO
  88. GRB000408, lotis optical observations
  89. GRB 000301C: Late-Time HST/STIS CCD Imaging of the field
  90. GRB000408 [IPN Position]
  91. GRB000326 Optical Observations
  92. GRB000301C - Addendum to GCN 623
  93. GRB000301C - R magnitude lower limit
  94. GRB000326, Further VLA observations
  95. GRB 000323, optical observations
  96. GRB 000326: Optical Observations
  97. GRB000326, Radio observations
  98. GRB000326 [IPN Position]
  99. GRB 000307 optical observations
  100. GRB000323 [IPN Position]

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