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"

35259 results found.

  1. IPN triangulation of GRB 001004
  2. Public availability of BeppoSAX data of GRB000926
  3. GRB000926: X-ray afterglow by BeppoSAX. Refined analysis
  4. GRB 000926, Optical Decay
  5. GRB000926 - Optical observations
  6. GRB000926 - Optical observations
  7. GRB 000926: optical observations
  8. GRB 000926, Optical Observations
  9. GRB000926 K'-band Observation
  10. GRB000926 : increasing optical decay slope
  11. GRB000926 optical observations
  12. GRB000926 - Optical observations
  13. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  14. J and K band observations of GRB 000926
  15. GRB 000926: Lightcurve Update and Predictions
  16. GRB 000926, optical observation by Oksanen (vsnet-grb)
  17. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  18. CONCAM crude optical limits before and after GRB000926
  19. GRB 000926: Preliminary R-band Lightcurve
  20. GRB 000926 HST/Chandra TOO Status
  21. Spectroscopic Redshift of GRB 000926
  22. GRB 000926, Optical Observation
  23. GRB 000926: Optical candidate
  24. Optical candidate for GRB000926
  25. IPN triangulation of GRB000926
  26. GRB 000911, BVRI field photometry
  27. GRB000911: Sub-millimeter observations
  28. IPN triangulation of GRB000925
  29. IPN triangulation of GRB000911
  30. IPN triangulation of GRB000910
  31. False GRB alarm from RXTE/ASM on 8 Sept 2000
  32. GRB 000830: Optical observations
  33. GRB000830: Optical observations
  34. GRB000830, TNG B-band observations
  35. GRB000830, BVRI field photometry
  36. GRB000830: Optical observations
  37. GRB000210, Optical observations
  38. Chandra Position of GRB000210
  39. "Snapshot" afterglow IDs and GRB 000830
  40. IPN triangulation of GRB000830
  41. HST/STIS observations of the host galaxy of GRB 980329
  42. HST/STIS observations of the chaotic environment of GRB 980613
  43. IPN localization of GRB000820
  44. GRB000801 & GRB000730, Gamma Ray Observations
  45. GRB000730, Gamma Ray Observations
  46. GRB000812, Radio observations
  47. IPN localization of GRB000812
  48. IPN localization of GRB000811
  49. GRB000801, Gamma Ray Observations
  50. GRB000801, VLT-Antu R-band observations
  51. GRB 991208 Host Galaxy Imaging
  52. Updated IPN coordinates for GRB000801
  53. IPN localization of GRB000801
  54. IPN localization of GRB000730B
  55. IPN localization of GRB000730B
  56. IPN localization of GRB000730
  57. GRB 990510: Possible detection of a host galaxy
  58. GRB 990510 Host Galaxy Discovery
  59. GRB 000727, optical observations
  60. IPN localization of GRB000727
  61. GRB 990705, HST/STIS observations of the host galaxy
  62. GRB 990712: Late time HST/STIS Observations
  63. GRB 991216, HST/STIS observations
  64. GRB981226, HST/STIS observations of the host galaxy
  65. GRB 000630: Detection of the Optical Afterglow
  66. GRB000630, Revised BVRI Field Photometry
  67. GRB000630, Optical Observations
  68. GRB000630, optical observations
  69. GRB000630, BVRI Field Photometry
  70. GRB000630, optical observations
  71. GRB000630: Optical observations
  72. possible optical counterpart of GRB 000630
  73. IPN triangulation of GRB000630
  74. GRB 000623, optical observations
  75. GRB 000620, optical observations
  76. GRB000418, HST/STIS Observations
  77. GRB990123: Late-time HST/STIS observations of the host
  78. GRB 990506, HST/STIS Observations of the Host Galaxy
  79. GRB000623
  80. GRB 000620: J-band observations
  81. GRB990308, HST/STIS observations of the host galaxy
  82. IPN annulus for GRB000620
  83. GRB000615, Radio observations
  84. GRB000607, optical observations
  85. GRB 000615: NIR further observations
  86. BeppoSAX ALERT: GRB000620
  87. GRB000620: BeppoSAX Alert
  88. GRB990123, HST/STIS observations of the host galaxy
  89. GRB 000615, near-infrared observations
  90. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  91. GRB000616 [IPN Position]
  92. GRB000615B [IPN Position]
  93. GRB000615, further R-band photometry
  94. GRB 000615: NIR observations
  95. GRB000615: BeppoSAX NFI follow-up preliminary analysis
  96. GRB000615, R-band photometry
  97. GRB980425, HST/STIS observations of the host galaxy
  98. GRB000615: BeppoSAX GRB Alert
  99. The Hosts of GRB 980703 and GRB 971214
  100. GRB 000301C: Further Late-Time HST/STIS 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