Skip to main content
New! Super-Kamiokande JSON Notices and Schema v4.5.0. 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"

2707 results found.

  1. Chandra observations of GW170817 ~581 days since merger
  2. GRB 190206A: AstroSat CZTI detection
  3. GRB 190203A: Swift-BAT refined analysis
  4. GRB 190204A: Swift detection of a burst with a possible optical counterpart
  5. GRB 190202A: LCO-CTIO optical observations
  6. GRB 190129B: DDOTI Detection of the Possible Afterglow and Suggestion of Fading
  7. GRB 190129B: GROND possible host candidate
  8. IceCube-190124A - IceCube observation of a high-energy neutrino candidate event
  9. GRB 190114C: GMRT detection at 1.26GHz
  10. Swift ToO Instructions Update
  11. Swift ToO Website Down
  12. GRB 190114C: RATIR Optical and NIR Detections
  13. GRB 190114C: COATLI Optical Detection
  14. GRB 190114B, Swift-BAT refined analysis
  15. GRB 190114C: SPI-ACS/INTEGRAL extended emission detection
  16. GRB 190114C: Possible host galaxy in Pan-STARRS
  17. GRB 190114B: Swift detection of a burst
  18. GRB 190114A: Possible UVOT Detection
  19. GRB 190106A: optical observations, possible jet break detection
  20. Correction to the GCN circ. 23654 / GRB 190109B: Mondy optical upper limit
  21. GRB 190106A: GMG spectral results
  22. GRB 181228A: possible NOT optical detection
  23. FRB 181228: Global MASTER Net optical inspection
  24. Swift Trigger 878504 is not astrophysical
  25. MASTER: OTs detection during Fermi alert trigger 565936249 early observations
  26. GRB 181201A: VLT/FORS2 tentative spectroscopic redshift
  27. Short-duration GRB 181121.4: MASTER-Tavrida possible OT detection near the PGC galaxy during large Fermi error box inspection
  28. GRB 181123B: Keck near-infrared imaging
  29. GRB 181110A: Kanata 1.5m optical observation
  30. Fermi GRB 181105.31: Global MASTER Net optical observations
  31. GRB 181030A: Swift detection of a burst with a possible optical counterpart
  32. IceCube-181023A - IceCube observation of a high-energy neutrino candidate event
  33. GRB 181020A: Global MASTER Net OT observations
  34. IceCube-181014A - IceCube observation of a high-energy neutrino candidate event
  35. IceCube-180908A - IceCube observation of a high-energy neutrino candidate event
  36. GRB 180828A: Swift detection of a GRB or possible Galactic Transient Swift J1754.9-2548
  37. GRB 180728A: discovery of the associated supernova
  38. Swift Trigger 852625: Swift/BAT/XRT/UVOT observations
  39. GRB 180809B: CALET Gamma-Ray Burst Monitor detection
  40. Swift Trigger 852625: a possible GRB
  41. GRB 180806.94: MASTER possible OT detection in Fermi GMB trigger 555287944 error box
  42. GMRT radio detection of GRB 180720B
  43. GRB 180728B: GOTO optical search over IPN region
  44. GRB 180728B: MASTER optical observations short GRB IPN error box
  45. GRB 180720C: Swift detection of a burst or possible Galactic Transient
  46. GRB 180720B: LCO Haleakala possible bright optical candidate
  47. GRB 180715A: LCO Sutherland possible optical candidate
  48. GRB 180705A: OSN observations
  49. Konus-Wind observation of GRB 180704A
  50. GRB 180703A: LCO Sutherland possible optical candidate
  51. GRB150101B: INTEGRAL prompt gamma-ray signal from a possible GRB170817A-analogue
  52. GRB 180626C : GOTO optical observations
  53. GRB 180626B : GOTO optical observations
  54. GRB 180613A: Possible IR afterglow
  55. GRB 180613A: Possible host galaxy at XRT position, or star
  56. GRB 180529A: CALET Gamma-Ray Burst Monitor detection
  57. AGILE/MCAL detection of GRB 180529 and a possible precursor
  58. Swift Trigger 831888: a possible GRB or Galactic transient
  59. GRB 180510B: Swift detection of a burst with an optical counterpart
  60. Chandra observations of GW170817 reveal a fading afterglow
  61. Chandra observations of GW170817 260 days since merger: first statistically significant evidence for an X-ray decay
  62. GRB 180418A GROND observations
  63. Chandra observations of GRB161219B 400 days after the explosion
  64. Swift Trigger 819301: possible GRB 180329A
  65. GRB 180324A: RATIR Optical Observations and Possible Afterglow Detection
  66. GRB 180316A: RATIR Optical Observations, Possible Re-brightening
  67. GRB 180224A: AbAO optical observations
  68. Swift trigger 811074 (possible GRB 180221A): Swift refined analysis
  69. GRB180221A: MASTER-OAFA optical observations
  70. Swift Trigger 811074: possible GRB 180221A
  71. Trigger 809374: Swift detection of a possible non-burst faint source
  72. Fermi-GBM Detection of possible burst from AXP CXOU J164710.2-455216/PSR J1647-4552
  73. LIGO/Virgo GW170817: Chandra X-ray Emission Continues to Rise ~156 Days Post-Merger
  74. GRB 180120A CALET Gamma-Ray Burst Monitor detection
  75. GRB180111A: Xinglong TNT possible optical detection
  76. GRB 180103A: LCO Sutherland 1-m telescope observations
  77. GRB 171209A: Swift/UVOT Analysis of the burst
  78. GRB 171209A: Swift detection of a burst
  79. LIGO/Virgo G298048: Brightening X-ray Emission from GW170817/GRB170817A/SSS17a
  80. LIGO/Virgo GW170817: Chandra X-ray brightening of the counterpart 108 days since merger
  81. GRB 171205A: Host galaxy photometric properties
  82. Possible blackbody component in the X-ray spectrum of GRB171205A
  83. Pan-STARRS follow-up of IceCube-171106A
  84. GRB 171123A: Swift detection of a burst
  85. GRB 171010A: possible SN component
  86. IceCube-171106A - IceCube observation of a high-energy neutrino candidate
  87. GRB 171030A: MASTER inspection of the IPN error box of the short GRB.
  88. GRB 171103A: Fermi GBM observation
  89. GRB 171010A: VLT spectroscopic identification of the associated SN 2017htp
  90. GRB 171030A: IPN error box through NSs probability merging rate map
  91. Swift trigger 781740: Further analysis from Swift and Fermi/GBM
  92. Fermi-GBM Detection of possible burst from AXP CXOU J164710.2-455216/PSR J1647-4552
  93. Swift trigger 779171 is probably a noise fluctuation
  94. IceCube-171015A - IceCube observation of a high-energy neutrino candidate event
  95. BAT trigger 778435 is not a GRB.
  96. GRB 171013A: Swift detection of a possible burst
  97. GRB 171010A: Swift/UVOT Detection
  98. GRB 171010A: ePESSTO NTT spectroscopic redshift
  99. GRB 171010A: OT, spectrum, and possible host galaxy
  100. LIGO/Virgo G298048: Mid-Infrared Spitzer/IRAC Observations at 3.6 and 4.5 microns

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