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"

36154 results found.

  1. GRB040924, BVRcIc field calibration
  2. GRB041015: MASTER: Optical observations
  3. GRB041015,optical observation
  4. GRB 041015: Optical limit at Osaka University
  5. GRB041015 : Optical follow-up at Kiso
  6. GRB 041015 - A long GRB detected by INTEGRAL
  7. GRB 041006 R observations in Loiano
  8. GRB041006: VLT observations of the afterglow and host galaxy
  9. GRB041006: Optical observations and Potential host galaxy
  10. GRB041006, BVRcIc field calibration
  11. GRB 040924: VLT spectroscopy
  12. GRB 041006: SARA afterglow observations
  13. Search for SN light in XRF 040912 with MEGACAM
  14. GRB 040916: Afterglow Color at Early Times
  15. GRB 041006 Optical afterglow observations
  16. IBAS GRB Alert # 2010
  17. GRB 041006: BR observations with VATT
  18. GRB 041006: Redshift confirmed
  19. GRB041006: Liverpool Telescope optical observations
  20. GRB 041006: Colour measurement
  21. GRB041006: break in the light curve
  22. GRB 041006: Radio Observations
  23. GRB041006, further submilllimetre observations
  24. GRB 041006 : optical follow-up observation at Lulin Observatory
  25. GRB 041006 : Optical follow-up observation at TAROT
  26. GRB041006: Optical photometry and spectroscopy at TNG
  27. GRB 041006: presice astrometry
  28. GRB041006 (= H3570): Chandra Observations In Progress
  29. GRB 041006 : optical observation at Bisei
  30. GRB041006 (=HETE3570): optical observations
  31. ROTSE-IIIa Observations of GRB 041006
  32. GRB041006, submillimetre observations
  33. GRB041006: MASTER optical observations
  34. GRB 041006: Optical decay
  35. GRB 041006 (=H3570): An X-Ray Rich GRB Localized in Real Time by HETE
  36. GRB 041006 : Optical follow-up observation at KISO
  37. GRB 041006: Finding chart
  38. GRB 041006: Optical afterglow candidate
  39. XRF 020903: Observations of the Host Galaxy (authors)
  40. GRB 040924: Second Epoch WSRT Radio Observations
  41. radio observations, GRB 040924
  42. IBAS Alert 1991. Not a real GRB
  43. GRB040929,optical observation
  44. GRB040924,optical observation
  45. GRB040924, RTT150 optical observation
  46. GRB 040924: detection of possible host galaxy by Subaru
  47. GRB040924, RTT150 optical observation
  48. GRB040924: KAIT observations
  49. GRB040924: Afterglow magnitude at t=17.5hr
  50. GRB 040924: WSRT Radio Observations
  51. GRB 040924: NIR finding chart
  52. GRB040924 : Optical candidate observations at Lulin observatory
  53. GRB040924 : Optical candidate observations at Lulin observatory
  54. GRB 040924: Subaru NIR observation
  55. GRB 040924: RTT150 optical observations
  56. GRB 040924, optical follow-up
  57. IPN triangulation of GRB040924 (H3564)
  58. GRB 040924(=H3564): A Short, Bright GRB Localized in Real Time by HETE
  59. GRB040912(=H3557): Chandra Candidate X-ray Afterglow
  60. XRF040916: continuing decay of OT
  61. TAROT Observations of GRB 040916 (HETE #3558)
  62. XRF040916, optical observations
  63. XRF040916: Optical Transient Candidate by Subaru
  64. GRB040916 optical limits 17 min after GRB
  65. XRF 040912 (=H3557): Spectral and Temporal Properties
  66. XRF040916, Ic observations
  67. XRF040912, BVRcIc field calibration
  68. XRF040916, BVRcIc field calibration
  69. GRB040916: Archival optical observations
  70. GRB040912(=H3557): Observations with the Chandra X-ray Observatory
  71. GRB040916: Optical observations
  72. ROTSE-IIIb Observations of GRB 040916 (HETE #3558)
  73. GRB040912 (= H3557): Chandra Observations Scheduled
  74. GRB 040912: Optical Observations
  75. GRB/XRF040912,optical observations
  76. GRB 040912, BVRI observations
  77. Optical observations of GRB/XRF 040912 = HETE 3557
  78. An intense burst from SGR1806-20
  79. IBAS GRB Alerts 1978-1980
  80. Optical observations of field of GRB040912
  81. GRB040912 (= H3557): A Long GRB or XRF Localized by HETE
  82. GRB 040827: XMM-Newton data
  83. GRB040903 - A XRF?
  84. GRB040827: analysis of the XMM-Newton observation
  85. GRB 040903 - INTEGRAL data analysis
  86. IBAS Alert 1974. Not a real GRB
  87. Very bright burst detected from SGR 1806-20
  88. ROTSE-III Rapid Response to possible GRB 040903 (INTEGRAL #1972)
  89. Possible GRB 040903 - further analysis
  90. Possible GRB 040903 detected with INTEGRAL
  91. GRB 040827 - Radio Observations
  92. XMM-Newton Images of GRB 040827
  93. GRB 040827: optical and NIR observations at the VLT
  94. GRB 040827: UKIRT - 2nd epoch K-band imaging
  95. GRB 040827: 2nd epoch of Magellan K-band imaging
  96. GRB 040827: K imaging - no evidence of variability
  97. GRB 040827: Detection of NIR afterglow
  98. GRB 040827: Possible detection of optical afterglow
  99. GRB 040827: RTT150 optical observations
  100. GRB040825A: optical limit before GRB

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