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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

5822 results found.

  1. LIGO/Virgo/KAGRA S240920dw: Identification of a GW compact binary merger candidate
  2. EP EP240919a: Global MASTER-Net observations report
  3. EP240918a: 1.6m Mephisto multi-band Optical Upper Limit
  4. EP240919a: NOT and Gemini optical observations
  5. EP240919a: GOTO optical upper limits
  6. EP240919a: JinShan optical upper limits
  7. EP240919a is likely a GRB event
  8. LIGO/Virgo/KAGRA S240920bz: Identification of a GW compact binary merger candidate
  9. EP240919a: EP-WXT detection of a fast X-ray transient
  10. EP240918b and EP240918c: EP-WXT detection of two fast X-ray transients
  11. EP240918a: EP observation update
  12. LIGO/Virgo/KAGRA S240919bn: Identification of a GW compact binary merger candidate
  13. EP240918a: Swift-XRT observation
  14. Fermi GRB 240918A: Global MASTER-Net observations report
  15. EP EP240918a: Global MASTER-Net observations report
  16. EP240918a: JinShan optical upper limits
  17. EP240918a: YAHPT Optical Upper Limit
  18. EP240918a: GMG Optical Upper Limit
  19. GRB 240916A: GRBAlpha detection
  20. GRB 240914B: GRBAlpha detection
  21. EP240918a: an X-ray transient detected by Einstein Probe
  22. GRB 240916A: NOT optical observation
  23. LIGO/Virgo/KAGRA S240917cb: Identification of a GW compact binary merger candidate
  24. LIGO/Virgo/KAGRA S240916ar: Identification of a GW compact binary merger candidate
  25. LIGO/Virgo/KAGRA S240915b: NED Galaxies in the Localization Volume
  26. GRB 240916A: JinShan optical decay in one of the two GOTO candidates
  27. GRB 240914B: Fermi GBM Final Localization
  28. The EP-WXT triggers 01709047257 and 01709047278 are not real sources
  29. GRB 240916A: GOTO identification of two new optical sources within the GBM localisation region
  30. EP EP240913a: Global MASTER-Net observations report
  31. LIGO/Virgo/KAGRA S240915b: Coverage and upper limits from MAXI/GSC observations
  32. EP240913a: VLT/HAWK-I near-infrared upper limits
  33. LIGO/Virgo/KAGRA S240915bd: Identification of a GW compact binary merger candidate
  34. LIGO/Virgo/KAGRA S240915b: Identification of a GW compact binary merger candidate
  35. EP240913a / GRB 240913C INTEGRAL SPI ACS LIGHT CURVE
  36. GRB 240913C: Joint location by ETJASMIN
  37. GRB 240914B: AstroSat CZTI detection
  38. EP240913A / GRB 240913C: AstroSat CZTI detection
  39. GRB 240914A: SVOM/GRM observation
  40. GRB 240910A: SVOM/VT optical observations
  41. EP240913a: NOT optical upper limits
  42. EP240913a: JinShan optical upper limits
  43. EP240913a: ESO-NTT optical observations
  44. GRB 240914A: ESO-NTT optical observations
  45. EP240913a: Swift/XRT detection of an X-ray source within the EP/WXT error circle
  46. GRB 240914B: BALROG localization (Fermi Trigger 747990592 / GRB 240914298)
  47. GRB 240914A : An intermediate duration GRB located on-board by SVOM/ECLAIRs.
  48. GRB 240905E: further NOT optical observations
  49. EP240913a: A GRB Event
  50. EP240913a: EP-WXT detection of a fast X-ray transient
  51. GRB 240911A: JinShan optical upper limits on two Swift/XRT candidates
  52. GRB 240911A: GOTO optical limits on Swift/XRT candidates
  53. Fermi trigger No 747920561: Global MASTER-Net observations report
  54. GRB 240912A: SVOM/GRM observation
  55. Fermi GRB 240913A: Global MASTER-Net observations report
  56. GRB 240912A: J-band observations with WINTER
  57. Swift GRB 240912A: Global MASTER-Net observations report
  58. GRB 240912A: LCOGT detection and Legacy Surveys likely host galaxy
  59. GRB 240912A: NOT optical spectroscopy
  60. GRB 240912A: Redshift from OSIRIS+/GTC
  61. GRB 240910A: Redshift from OSIRIS+/GTC
  62. GRB 240911A : a likely weak GRB detected by SVOM/ECLAIRs
  63. GRB 240910A: GOTO candidate optical counterpart
  64. GRB 240825A: 7DT Optical Upper Limit
  65. GRB 240905E: SVOM/VT optical observations
  66. GRB 240910A: GRBAlpha detection
  67. LIGO/Virgo/KAGRA S240910ci: Coverage and upper limits from MAXI/GSC observations
  68. LIGO/Virgo/KAGRA S240910ci: Identification of a GW compact binary merger candidate
  69. GRB 240910A: SVOM/GRM observation
  70. EP240908a: Mondy and AbAO follow-up observations
  71. EP240908a: Updates on the WXT detection result around the trigger time
  72. Fermi GRB 240910A: Global MASTER-Net observations report
  73. EP EP240908a: Global MASTER-Net observations report
  74. Fermi trigger No 747553301: Global MASTER-Net observations report
  75. EP240908a: TRT optical upper limit
  76. GRB 240905B: GOTO optical upper limits
  77. EP240908a: EP detection of a fast X-ray transient
  78. Fermi GRB 240908A: Global MASTER-Net observations report
  79. LIGO/Virgo/KAGRA S240908dg: Identification of a GW compact binary merger candidate
  80. LIGO/Virgo/KAGRA S240908bs: Identification of a GW compact binary merger candidate
  81. LIGO/Virgo/KAGRA S240907cg: Identification of a GW compact binary merger candidate
  82. GRB 240905E: GIT optical upper limit
  83. GRB 240905E: Gaoyazi/GOT optical upper limits
  84. GRB 240905E: NUTTelA-TAO / BSTI Optical Limits
  85. GRB 240905E: J-band observations with WINTER
  86. GRB 240905E: CrAO Optical Afterglow observations, possible OT candidate
  87. Fermi GRB 240905D: Global MASTER-Net observations report
  88. Fermi GRB 240905A: Global MASTER-Net observations report
  89. GRB 240905E: NOT optical upper limits
  90. GRB 240902B: AstroSat CZTI detection of a long burst
  91. GRB 240902A: AstroSat CZTI detection of a long burst
  92. GRB 240905E: SVOM/GRM observation
  93. GRB 240905E: SAO RAS optical upper limit
  94. GRB 240905E: Nanshan/HMT optical upper limit
  95. Swift GRB 240905E: Global MASTER-Net observations report
  96. GRB 240905E: Swift detection of a burst
  97. GRB 240905D: AstroSat CZTI detection
  98. GRB 240905A: SVOM/GRM observation
  99. Fermi GRB 240905B: Global MASTER-Net observations report
  100. GRB 240905B: AstroSat CZTI detection and localization

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