Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! 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"

32490 results found.

  1. GRB000911: optical VLT observations
  2. GRB000926 : increasing optical decay slope
  3. GRB000926 optical observations
  4. GRB000926 - Optical observations
  5. Re: GRB 000926, optical observation by Oksanen (vsnet-grb)
  6. J and K band observations of GRB 000926
  7. GRB000911 Optical Observations
  8. GRB 000926: Lightcurve Update and Predictions
  9. GRB 000926, optical observation by Oksanen (vsnet-grb)
  10. GRB000926: X-ray afterglow by BeppoSAX & plan of BSAX & Chandra obs.
  11. GRB000926: Optical observations
  12. GRB 000926: Preliminary R-band Lightcurve
  13. GRB 000926 HST/Chandra TOO Status
  14. Spectroscopic Redshift of GRB 000926
  15. GRB 000926, Optical Observation
  16. GRB000926, radio observations
  17. GRB 000926: Optical candidate
  18. Optical candidate for GRB000926
  19. IPN triangulation of GRB000926
  20. GRB 000911, BVRI field photometry
  21. GRB000911: Corrected coordinates
  22. GRB000911: Sub-millimeter observations
  23. GRB000911: Optical Transient
  24. GRB000911, Radio and Optical observations
  25. GRB000911, Radio observations
  26. GRB000911: Optical observations
  27. False GRB alarm from RXTE/ASM on 8 Sept 2000
  28. GRB 000830: Optical observations
  29. GRB000830: Optical observations
  30. GRB000830, TNG B-band observations
  31. GRB000830: Optical observations
  32. GRB000210, Optical observations
  33. Chandra Position of GRB000210
  34. GRB000830: Optical observations
  35. HST/STIS observations of the host galaxy of GRB 980329
  36. HST/STIS observations of the chaotic environment of GRB 980613
  37. GRB000812, TNG R-band observations
  38. GRB000801 & GRB000730, Gamma Ray Observations
  39. GRB000812, Radio observations
  40. GRB000801, VLT-Antu R-band observations
  41. GRB000301C, UBVI optical observations
  42. GRB000801, Radio Observations
  43. GRB 991208 Host Galaxy Imaging
  44. Updated IPN coordinates for GRB000801
  45. IPN localization of GRB000801
  46. IPN localization of GRB000730B
  47. GRB 990510: Possible detection of a host galaxy
  48. GRB 990510 Host Galaxy Discovery
  49. GRB 000727, optical observations
  50. GRB 990705, HST/STIS observations of the host galaxy
  51. GRB 990712: Late time HST/STIS Observations
  52. GRB 991216, HST/STIS observations
  53. GRB000620, Radio Observations
  54. GRB981226, HST/STIS observations of the host galaxy
  55. GRB000630, optical observations
  56. GRB 000630: Detection of the Optical Afterglow
  57. GRB000630, Revised BVRI Field Photometry
  58. GRB000630, Optical Observations
  59. GRB000630, optical observations
  60. GRB000630, optical observations
  61. GRB000630, optical observations
  62. GRB000630, optical observations
  63. GRB000630: Optical observations
  64. GRB000630, Radio Observations
  65. possible optical counterpart of GRB 000630
  66. GRB 000623, optical observations
  67. GRB 000620, optical observations
  68. GRB000418, HST/STIS Observations
  69. GRB990123: Late-time HST/STIS observations of the host
  70. GRB 990506, HST/STIS Observations of the Host Galaxy
  71. GRB 000620: J-band observations
  72. GRB000620, optical observations
  73. GRB000615: H-band observations
  74. GRB990308, HST/STIS observations of the host galaxy
  75. GRB000620 - Optical observations
  76. GRB000620 Optical observations
  77. IPN annulus for GRB000620
  78. GRB000615, Radio observations
  79. GRB000607, optical observations
  80. GRB 000615: NIR further observations
  81. GRB990123, HST/STIS observations of the host galaxy
  82. GRB000616 optical observations
  83. GRB 000615, near-infrared observations
  84. GRB 990123: Late-time HST/STIS 50CCD observations of the host
  85. GRB000615, further R-band photometry
  86. GRB 000615: NIR observations
  87. GRB000615, R-band photometry
  88. GRB980425, HST/STIS observations of the host galaxy
  89. The Hosts of GRB 980703 and GRB 971214
  90. GRB 000301C: Further Late-Time HST/STIS observations
  91. GRB000528: follow-up X-ray measurements and update of IPN annulus
  92. Optical Follow-up of GRB000529 Error Box
  93. GRB000607, Radio Observations
  94. GRB000604 optical non-detection
  95. GRB000604 - Optical observations
  96. GRB000604, optical observations
  97. GRB000528, optical observations at ESO
  98. GRB 000604 optical observations
  99. GRB 000418: Detection of the Host Galaxy
  100. GRB000604, optical observations, comparison with DPOSS

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
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